#include "postgres.h"
#include "access/htup_details.h"
#include "catalog/objectaccess.h"
#include "catalog/pg_aggregate.h"
#include "catalog/pg_proc.h"
#include "executor/executor.h"
#include "executor/nodeWindowAgg.h"
#include "miscadmin.h"
#include "nodes/nodeFuncs.h"
#include "optimizer/clauses.h"
#include "optimizer/optimizer.h"
#include "parser/parse_agg.h"
#include "parser/parse_coerce.h"
#include "utils/acl.h"
#include "utils/builtins.h"
#include "utils/datum.h"
#include "utils/expandeddatum.h"
#include "utils/lsyscache.h"
#include "utils/memutils.h"
#include "utils/regproc.h"
#include "utils/syscache.h"
#include "windowapi.h"

Include dependency graph for nodeWindowAgg.c:

Data Structures
struct	WindowObjectData

struct	WindowStatePerFuncData

struct	WindowStatePerAggData

Typedefs
typedef struct WindowObjectData	WindowObjectData

typedef struct WindowStatePerFuncData	WindowStatePerFuncData

typedef struct WindowStatePerAggData	WindowStatePerAggData

Functions
static void	initialize_windowaggregate (WindowAggState *winstate, WindowStatePerFunc perfuncstate, WindowStatePerAgg peraggstate)

static void	advance_windowaggregate (WindowAggState *winstate, WindowStatePerFunc perfuncstate, WindowStatePerAgg peraggstate)

static bool	advance_windowaggregate_base (WindowAggState *winstate, WindowStatePerFunc perfuncstate, WindowStatePerAgg peraggstate)

static void	finalize_windowaggregate (WindowAggState winstate, WindowStatePerFunc perfuncstate, WindowStatePerAgg peraggstate, Datum result, bool *isnull)

static void	eval_windowaggregates (WindowAggState *winstate)

static void	eval_windowfunction (WindowAggState winstate, WindowStatePerFunc perfuncstate, Datum result, bool *isnull)

static void	begin_partition (WindowAggState *winstate)

static void	spool_tuples (WindowAggState *winstate, int64 pos)

static void	release_partition (WindowAggState *winstate)

static int	row_is_in_frame (WindowAggState winstate, int64 pos, TupleTableSlot slot)

static void	update_frameheadpos (WindowAggState *winstate)

static void	update_frametailpos (WindowAggState *winstate)

static void	update_grouptailpos (WindowAggState *winstate)

static WindowStatePerAggData *	initialize_peragg (WindowAggState winstate, WindowFunc wfunc, WindowStatePerAgg peraggstate)

static Datum	GetAggInitVal (Datum textInitVal, Oid transtype)

static bool	are_peers (WindowAggState winstate, TupleTableSlot slot1, TupleTableSlot *slot2)

static bool	window_gettupleslot (WindowObject winobj, int64 pos, TupleTableSlot *slot)

static pg_noinline void	prepare_tuplestore (WindowAggState *winstate)

static pg_noinline void	calculate_frame_offsets (PlanState *pstate)

static TupleTableSlot *	ExecWindowAgg (PlanState *pstate)

WindowAggState *	ExecInitWindowAgg (WindowAgg node, EState estate, int eflags)

void	ExecEndWindowAgg (WindowAggState *node)

void	ExecReScanWindowAgg (WindowAggState *node)

void *	WinGetPartitionLocalMemory (WindowObject winobj, Size sz)

int64	WinGetCurrentPosition (WindowObject winobj)

int64	WinGetPartitionRowCount (WindowObject winobj)

void	WinSetMarkPosition (WindowObject winobj, int64 markpos)

bool	WinRowsArePeers (WindowObject winobj, int64 pos1, int64 pos2)

Datum	WinGetFuncArgInPartition (WindowObject winobj, int argno, int relpos, int seektype, bool set_mark, bool isnull, bool isout)

Datum	WinGetFuncArgInFrame (WindowObject winobj, int argno, int relpos, int seektype, bool set_mark, bool isnull, bool isout)

Datum	WinGetFuncArgCurrent (WindowObject winobj, int argno, bool *isnull)

Typedef Documentation

◆ WindowObjectData

typedef struct WindowObjectData WindowObjectData

◆ WindowStatePerAggData

typedef struct WindowStatePerAggData WindowStatePerAggData

◆ WindowStatePerFuncData

typedef struct WindowStatePerFuncData WindowStatePerFuncData

Function Documentation

◆ advance_windowaggregate()

static void advance_windowaggregate	(	WindowAggState *	winstate,
		WindowStatePerFunc	perfuncstate,
		WindowStatePerAgg	peraggstate
	)

static

Definition at line 242 of file nodeWindowAgg.c.

{
    LOCAL_FCINFO(fcinfo, FUNC_MAX_ARGS);
    WindowFuncExprState *wfuncstate = perfuncstate->wfuncstate;
    int         numArguments = perfuncstate->numArguments;
    Datum       newVal;
    ListCell   *arg;
    int         i;
    MemoryContext oldContext;
    ExprContext *econtext = winstate->tmpcontext;
    ExprState  *filter = wfuncstate->aggfilter;
 
    oldContext = MemoryContextSwitchTo(econtext->ecxt_per_tuple_memory);
 
    /* Skip anything FILTERed out */
    if (filter)
    {
        bool        isnull;
        Datum       res = ExecEvalExpr(filter, econtext, &isnull);
 
        if (isnull || !DatumGetBool(res))
        {
            MemoryContextSwitchTo(oldContext);
            return;
        }
    }
 
    /* We start from 1, since the 0th arg will be the transition value */
    i = 1;
    foreach(arg, wfuncstate->args)
    {
        ExprState  *argstate = (ExprState *) lfirst(arg);
 
        fcinfo->args[i].value = ExecEvalExpr(argstate, econtext,
                                             &fcinfo->args[i].isnull);
        i++;
    }
 
    if (peraggstate->transfn.fn_strict)
    {
        /*
         * For a strict transfn, nothing happens when there's a NULL input; we
         * just keep the prior transValue.  Note transValueCount doesn't
         * change either.
         */
        for (i = 1; i <= numArguments; i++)
        {
            if (fcinfo->args[i].isnull)
            {
                MemoryContextSwitchTo(oldContext);
                return;
            }
        }
 
        /*
         * For strict transition functions with initial value NULL we use the
         * first non-NULL input as the initial state.  (We already checked
         * that the agg's input type is binary-compatible with its transtype,
         * so straight copy here is OK.)
         *
         * We must copy the datum into aggcontext if it is pass-by-ref.  We do
         * not need to pfree the old transValue, since it's NULL.
         */
        if (peraggstate->transValueCount == 0 && peraggstate->transValueIsNull)
        {
            MemoryContextSwitchTo(peraggstate->aggcontext);
            peraggstate->transValue = datumCopy(fcinfo->args[1].value,
                                                peraggstate->transtypeByVal,
                                                peraggstate->transtypeLen);
            peraggstate->transValueIsNull = false;
            peraggstate->transValueCount = 1;
            MemoryContextSwitchTo(oldContext);
            return;
        }
 
        if (peraggstate->transValueIsNull)
        {
            /*
             * Don't call a strict function with NULL inputs.  Note it is
             * possible to get here despite the above tests, if the transfn is
             * strict *and* returned a NULL on a prior cycle.  If that happens
             * we will propagate the NULL all the way to the end.  That can
             * only happen if there's no inverse transition function, though,
             * since we disallow transitions back to NULL when there is one.
             */
            MemoryContextSwitchTo(oldContext);
            Assert(!OidIsValid(peraggstate->invtransfn_oid));
            return;
        }
    }
 
    /*
     * OK to call the transition function.  Set winstate->curaggcontext while
     * calling it, for possible use by AggCheckCallContext.
     */
    InitFunctionCallInfoData(*fcinfo, &(peraggstate->transfn),
                             numArguments + 1,
                             perfuncstate->winCollation,
                             (Node *) winstate, NULL);
    fcinfo->args[0].value = peraggstate->transValue;
    fcinfo->args[0].isnull = peraggstate->transValueIsNull;
    winstate->curaggcontext = peraggstate->aggcontext;
    newVal = FunctionCallInvoke(fcinfo);
    winstate->curaggcontext = NULL;
 
    /*
     * Moving-aggregate transition functions must not return null, see
     * advance_windowaggregate_base().
     */
    if (fcinfo->isnull && OidIsValid(peraggstate->invtransfn_oid))
        ereport(ERROR,
                (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
                 errmsg("moving-aggregate transition function must not return null")));
 
    /*
     * We must track the number of rows included in transValue, since to
     * remove the last input, advance_windowaggregate_base() mustn't call the
     * inverse transition function, but simply reset transValue back to its
     * initial value.
     */
    peraggstate->transValueCount++;
 
    /*
     * If pass-by-ref datatype, must copy the new value into aggcontext and
     * free the prior transValue.  But if transfn returned a pointer to its
     * first input, we don't need to do anything.  Also, if transfn returned a
     * pointer to a R/W expanded object that is already a child of the
     * aggcontext, assume we can adopt that value without copying it.  (See
     * comments for ExecAggCopyTransValue, which this code duplicates.)
     */
    if (!peraggstate->transtypeByVal &&
        DatumGetPointer(newVal) != DatumGetPointer(peraggstate->transValue))
    {
        if (!fcinfo->isnull)
        {
            MemoryContextSwitchTo(peraggstate->aggcontext);
            if (DatumIsReadWriteExpandedObject(newVal,
                                               false,
                                               peraggstate->transtypeLen) &&
                MemoryContextGetParent(DatumGetEOHP(newVal)->eoh_context) == CurrentMemoryContext)
                 /* do nothing */ ;
            else
                newVal = datumCopy(newVal,
                                   peraggstate->transtypeByVal,
                                   peraggstate->transtypeLen);
        }
        if (!peraggstate->transValueIsNull)
        {
            if (DatumIsReadWriteExpandedObject(peraggstate->transValue,
                                               false,
                                               peraggstate->transtypeLen))
                DeleteExpandedObject(peraggstate->transValue);
            else
                pfree(DatumGetPointer(peraggstate->transValue));
        }
    }
 
    MemoryContextSwitchTo(oldContext);
    peraggstate->transValue = newVal;
    peraggstate->transValueIsNull = fcinfo->isnull;
}

References WindowStatePerAggData::aggcontext, WindowFuncExprState::aggfilter, arg, WindowFuncExprState::args, Assert(), WindowAggState::curaggcontext, CurrentMemoryContext, datumCopy(), DatumGetBool(), DatumGetEOHP(), DatumGetPointer(), DatumIsReadWriteExpandedObject, DeleteExpandedObject(), ExprContext::ecxt_per_tuple_memory, ereport, errcode(), errmsg(), ERROR, ExecEvalExpr(), FmgrInfo::fn_strict, FUNC_MAX_ARGS, FunctionCallInvoke, i, InitFunctionCallInfoData, WindowStatePerAggData::invtransfn_oid, lfirst, LOCAL_FCINFO, MemoryContextGetParent(), MemoryContextSwitchTo(), WindowStatePerFuncData::numArguments, OidIsValid, pfree(), WindowAggState::tmpcontext, WindowStatePerAggData::transfn, WindowStatePerAggData::transtypeByVal, WindowStatePerAggData::transtypeLen, WindowStatePerAggData::transValue, WindowStatePerAggData::transValueCount, WindowStatePerAggData::transValueIsNull, WindowStatePerFuncData::wfuncstate, and WindowStatePerFuncData::winCollation.

Referenced by eval_windowaggregates().

◆ advance_windowaggregate_base()

static bool advance_windowaggregate_base	(	WindowAggState *	winstate,
		WindowStatePerFunc	perfuncstate,
		WindowStatePerAgg	peraggstate
	)

static

Definition at line 419 of file nodeWindowAgg.c.

{
    LOCAL_FCINFO(fcinfo, FUNC_MAX_ARGS);
    WindowFuncExprState *wfuncstate = perfuncstate->wfuncstate;
    int         numArguments = perfuncstate->numArguments;
    Datum       newVal;
    ListCell   *arg;
    int         i;
    MemoryContext oldContext;
    ExprContext *econtext = winstate->tmpcontext;
    ExprState  *filter = wfuncstate->aggfilter;
 
    oldContext = MemoryContextSwitchTo(econtext->ecxt_per_tuple_memory);
 
    /* Skip anything FILTERed out */
    if (filter)
    {
        bool        isnull;
        Datum       res = ExecEvalExpr(filter, econtext, &isnull);
 
        if (isnull || !DatumGetBool(res))
        {
            MemoryContextSwitchTo(oldContext);
            return true;
        }
    }
 
    /* We start from 1, since the 0th arg will be the transition value */
    i = 1;
    foreach(arg, wfuncstate->args)
    {
        ExprState  *argstate = (ExprState *) lfirst(arg);
 
        fcinfo->args[i].value = ExecEvalExpr(argstate, econtext,
                                             &fcinfo->args[i].isnull);
        i++;
    }
 
    if (peraggstate->invtransfn.fn_strict)
    {
        /*
         * For a strict (inv)transfn, nothing happens when there's a NULL
         * input; we just keep the prior transValue.  Note transValueCount
         * doesn't change either.
         */
        for (i = 1; i <= numArguments; i++)
        {
            if (fcinfo->args[i].isnull)
            {
                MemoryContextSwitchTo(oldContext);
                return true;
            }
        }
    }
 
    /* There should still be an added but not yet removed value */
    Assert(peraggstate->transValueCount > 0);
 
    /*
     * In moving-aggregate mode, the state must never be NULL, except possibly
     * before any rows have been aggregated (which is surely not the case at
     * this point).  This restriction allows us to interpret a NULL result
     * from the inverse function as meaning "sorry, can't do an inverse
     * transition in this case".  We already checked this in
     * advance_windowaggregate, but just for safety, check again.
     */
    if (peraggstate->transValueIsNull)
        elog(ERROR, "aggregate transition value is NULL before inverse transition");
 
    /*
     * We mustn't use the inverse transition function to remove the last
     * input.  Doing so would yield a non-NULL state, whereas we should be in
     * the initial state afterwards which may very well be NULL.  So instead,
     * we simply re-initialize the aggregate in this case.
     */
    if (peraggstate->transValueCount == 1)
    {
        MemoryContextSwitchTo(oldContext);
        initialize_windowaggregate(winstate,
                                   &winstate->perfunc[peraggstate->wfuncno],
                                   peraggstate);
        return true;
    }
 
    /*
     * OK to call the inverse transition function.  Set
     * winstate->curaggcontext while calling it, for possible use by
     * AggCheckCallContext.
     */
    InitFunctionCallInfoData(*fcinfo, &(peraggstate->invtransfn),
                             numArguments + 1,
                             perfuncstate->winCollation,
                             (Node *) winstate, NULL);
    fcinfo->args[0].value = peraggstate->transValue;
    fcinfo->args[0].isnull = peraggstate->transValueIsNull;
    winstate->curaggcontext = peraggstate->aggcontext;
    newVal = FunctionCallInvoke(fcinfo);
    winstate->curaggcontext = NULL;
 
    /*
     * If the function returns NULL, report failure, forcing a restart.
     */
    if (fcinfo->isnull)
    {
        MemoryContextSwitchTo(oldContext);
        return false;
    }
 
    /* Update number of rows included in transValue */
    peraggstate->transValueCount--;
 
    /*
     * If pass-by-ref datatype, must copy the new value into aggcontext and
     * free the prior transValue.  But if invtransfn returned a pointer to its
     * first input, we don't need to do anything.  Also, if invtransfn
     * returned a pointer to a R/W expanded object that is already a child of
     * the aggcontext, assume we can adopt that value without copying it. (See
     * comments for ExecAggCopyTransValue, which this code duplicates.)
     *
     * Note: the checks for null values here will never fire, but it seems
     * best to have this stanza look just like advance_windowaggregate.
     */
    if (!peraggstate->transtypeByVal &&
        DatumGetPointer(newVal) != DatumGetPointer(peraggstate->transValue))
    {
        if (!fcinfo->isnull)
        {
            MemoryContextSwitchTo(peraggstate->aggcontext);
            if (DatumIsReadWriteExpandedObject(newVal,
                                               false,
                                               peraggstate->transtypeLen) &&
                MemoryContextGetParent(DatumGetEOHP(newVal)->eoh_context) == CurrentMemoryContext)
                 /* do nothing */ ;
            else
                newVal = datumCopy(newVal,
                                   peraggstate->transtypeByVal,
                                   peraggstate->transtypeLen);
        }
        if (!peraggstate->transValueIsNull)
        {
            if (DatumIsReadWriteExpandedObject(peraggstate->transValue,
                                               false,
                                               peraggstate->transtypeLen))
                DeleteExpandedObject(peraggstate->transValue);
            else
                pfree(DatumGetPointer(peraggstate->transValue));
        }
    }
 
    MemoryContextSwitchTo(oldContext);
    peraggstate->transValue = newVal;
    peraggstate->transValueIsNull = fcinfo->isnull;
 
    return true;
}

References WindowStatePerAggData::aggcontext, WindowFuncExprState::aggfilter, arg, WindowFuncExprState::args, Assert(), WindowAggState::curaggcontext, CurrentMemoryContext, datumCopy(), DatumGetBool(), DatumGetEOHP(), DatumGetPointer(), DatumIsReadWriteExpandedObject, DeleteExpandedObject(), ExprContext::ecxt_per_tuple_memory, elog, ERROR, ExecEvalExpr(), FmgrInfo::fn_strict, FUNC_MAX_ARGS, FunctionCallInvoke, i, InitFunctionCallInfoData, initialize_windowaggregate(), WindowStatePerAggData::invtransfn, lfirst, LOCAL_FCINFO, MemoryContextGetParent(), MemoryContextSwitchTo(), WindowStatePerFuncData::numArguments, WindowAggState::perfunc, pfree(), WindowAggState::tmpcontext, WindowStatePerAggData::transtypeByVal, WindowStatePerAggData::transtypeLen, WindowStatePerAggData::transValue, WindowStatePerAggData::transValueCount, WindowStatePerAggData::transValueIsNull, WindowStatePerAggData::wfuncno, WindowStatePerFuncData::wfuncstate, and WindowStatePerFuncData::winCollation.

Referenced by eval_windowaggregates().

◆ are_peers()

static bool are_peers	(	WindowAggState *	winstate,
		TupleTableSlot *	slot1,
		TupleTableSlot *	slot2
	)

static

Definition at line 3109 of file nodeWindowAgg.c.

{
    WindowAgg  *node = (WindowAgg *) winstate->ss.ps.plan;
    ExprContext *econtext = winstate->tmpcontext;
 
    /* If no ORDER BY, all rows are peers with each other */
    if (node->ordNumCols == 0)
        return true;
 
    econtext->ecxt_outertuple = slot1;
    econtext->ecxt_innertuple = slot2;
    return ExecQualAndReset(winstate->ordEqfunction, econtext);
}

References ExecQualAndReset(), if(), WindowAggState::ordEqfunction, WindowAgg::ordNumCols, PlanState::plan, ScanState::ps, WindowAggState::ss, and WindowAggState::tmpcontext.

Referenced by ExecWindowAgg(), row_is_in_frame(), update_frameheadpos(), update_frametailpos(), update_grouptailpos(), and WinRowsArePeers().

◆ begin_partition()

static void begin_partition ( WindowAggState * winstate )

static

Definition at line 1193 of file nodeWindowAgg.c.

{
    PlanState  *outerPlan = outerPlanState(winstate);
    int         numfuncs = winstate->numfuncs;
 
    winstate->partition_spooled = false;
    winstate->framehead_valid = false;
    winstate->frametail_valid = false;
    winstate->grouptail_valid = false;
    winstate->spooled_rows = 0;
    winstate->currentpos = 0;
    winstate->frameheadpos = 0;
    winstate->frametailpos = 0;
    winstate->currentgroup = 0;
    winstate->frameheadgroup = 0;
    winstate->frametailgroup = 0;
    winstate->groupheadpos = 0;
    winstate->grouptailpos = -1;    /* see update_grouptailpos */
    ExecClearTuple(winstate->agg_row_slot);
    if (winstate->framehead_slot)
        ExecClearTuple(winstate->framehead_slot);
    if (winstate->frametail_slot)
        ExecClearTuple(winstate->frametail_slot);
 
    /*
     * If this is the very first partition, we need to fetch the first input
     * row to store in first_part_slot.
     */
    if (TupIsNull(winstate->first_part_slot))
    {
        TupleTableSlot *outerslot = ExecProcNode(outerPlan);
 
        if (!TupIsNull(outerslot))
            ExecCopySlot(winstate->first_part_slot, outerslot);
        else
        {
            /* outer plan is empty, so we have nothing to do */
            winstate->partition_spooled = true;
            winstate->more_partitions = false;
            return;
        }
    }
 
    /* Create new tuplestore if not done already. */
    if (unlikely(winstate->buffer == NULL))
        prepare_tuplestore(winstate);
 
    winstate->next_partition = false;
 
    if (winstate->numaggs > 0)
    {
        WindowObject agg_winobj = winstate->agg_winobj;
 
        /* reset mark and see positions for aggregate functions */
        agg_winobj->markpos = -1;
        agg_winobj->seekpos = -1;
 
        /* Also reset the row counters for aggregates */
        winstate->aggregatedbase = 0;
        winstate->aggregatedupto = 0;
    }
 
    /* reset mark and seek positions for each real window function */
    for (int i = 0; i < numfuncs; i++)
    {
        WindowStatePerFunc perfuncstate = &(winstate->perfunc[i]);
 
        if (!perfuncstate->plain_agg)
        {
            WindowObject winobj = perfuncstate->winobj;
 
            winobj->markpos = -1;
            winobj->seekpos = -1;
        }
    }
 
    /*
     * Store the first tuple into the tuplestore (it's always available now;
     * we either read it above, or saved it at the end of previous partition)
     */
    tuplestore_puttupleslot(winstate->buffer, winstate->first_part_slot);
    winstate->spooled_rows++;
}

Referenced by ExecWindowAgg().

◆ calculate_frame_offsets()

static pg_noinline void calculate_frame_offsets ( PlanState * pstate )

static

Definition at line 2082 of file nodeWindowAgg.c.

{
    WindowAggState *winstate = castNode(WindowAggState, pstate);
    ExprContext *econtext;
    int         frameOptions = winstate->frameOptions;
    Datum       value;
    bool        isnull;
    int16       len;
    bool        byval;
 
    /* Ensure we've not been called before for this scan */
    Assert(winstate->all_first);
 
    econtext = winstate->ss.ps.ps_ExprContext;
 
    if (frameOptions & FRAMEOPTION_START_OFFSET)
    {
        Assert(winstate->startOffset != NULL);
        value = ExecEvalExprSwitchContext(winstate->startOffset,
                                          econtext,
                                          &isnull);
        if (isnull)
            ereport(ERROR,
                    (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
                     errmsg("frame starting offset must not be null")));
        /* copy value into query-lifespan context */
        get_typlenbyval(exprType((Node *) winstate->startOffset->expr),
                        &len,
                        &byval);
        winstate->startOffsetValue = datumCopy(value, byval, len);
        if (frameOptions & (FRAMEOPTION_ROWS | FRAMEOPTION_GROUPS))
        {
            /* value is known to be int8 */
            int64       offset = DatumGetInt64(value);
 
            if (offset < 0)
                ereport(ERROR,
                        (errcode(ERRCODE_INVALID_PRECEDING_OR_FOLLOWING_SIZE),
                         errmsg("frame starting offset must not be negative")));
        }
    }
 
    if (frameOptions & FRAMEOPTION_END_OFFSET)
    {
        Assert(winstate->endOffset != NULL);
        value = ExecEvalExprSwitchContext(winstate->endOffset,
                                          econtext,
                                          &isnull);
        if (isnull)
            ereport(ERROR,
                    (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
                     errmsg("frame ending offset must not be null")));
        /* copy value into query-lifespan context */
        get_typlenbyval(exprType((Node *) winstate->endOffset->expr),
                        &len,
                        &byval);
        winstate->endOffsetValue = datumCopy(value, byval, len);
        if (frameOptions & (FRAMEOPTION_ROWS | FRAMEOPTION_GROUPS))
        {
            /* value is known to be int8 */
            int64       offset = DatumGetInt64(value);
 
            if (offset < 0)
                ereport(ERROR,
                        (errcode(ERRCODE_INVALID_PRECEDING_OR_FOLLOWING_SIZE),
                         errmsg("frame ending offset must not be negative")));
        }
    }
    winstate->all_first = false;
}

References WindowAggState::all_first, Assert(), castNode, datumCopy(), DatumGetInt64(), WindowAggState::endOffset, WindowAggState::endOffsetValue, ereport, errcode(), errmsg(), ERROR, ExecEvalExprSwitchContext(), ExprState::expr, exprType(), FRAMEOPTION_END_OFFSET, FRAMEOPTION_GROUPS, FRAMEOPTION_ROWS, FRAMEOPTION_START_OFFSET, WindowAggState::frameOptions, get_typlenbyval(), len, ScanState::ps, PlanState::ps_ExprContext, WindowAggState::ss, WindowAggState::startOffset, WindowAggState::startOffsetValue, and value.

Referenced by ExecWindowAgg().

◆ eval_windowaggregates()

static void eval_windowaggregates ( WindowAggState * winstate )

static

Definition at line 663 of file nodeWindowAgg.c.

{
    WindowStatePerAgg peraggstate;
    int         wfuncno,
                numaggs,
                numaggs_restart,
                i;
    int64       aggregatedupto_nonrestarted;
    MemoryContext oldContext;
    ExprContext *econtext;
    WindowObject agg_winobj;
    TupleTableSlot *agg_row_slot;
    TupleTableSlot *temp_slot;
 
    numaggs = winstate->numaggs;
    if (numaggs == 0)
        return;                 /* nothing to do */
 
    /* final output execution is in ps_ExprContext */
    econtext = winstate->ss.ps.ps_ExprContext;
    agg_winobj = winstate->agg_winobj;
    agg_row_slot = winstate->agg_row_slot;
    temp_slot = winstate->temp_slot_1;
 
    /*
     * If the window's frame start clause is UNBOUNDED_PRECEDING and no
     * exclusion clause is specified, then the window frame consists of a
     * contiguous group of rows extending forward from the start of the
     * partition, and rows only enter the frame, never exit it, as the current
     * row advances forward.  This makes it possible to use an incremental
     * strategy for evaluating aggregates: we run the transition function for
     * each row added to the frame, and run the final function whenever we
     * need the current aggregate value.  This is considerably more efficient
     * than the naive approach of re-running the entire aggregate calculation
     * for each current row.  It does assume that the final function doesn't
     * damage the running transition value, but we have the same assumption in
     * nodeAgg.c too (when it rescans an existing hash table).
     *
     * If the frame start does sometimes move, we can still optimize as above
     * whenever successive rows share the same frame head, but if the frame
     * head moves beyond the previous head we try to remove those rows using
     * the aggregate's inverse transition function.  This function restores
     * the aggregate's current state to what it would be if the removed row
     * had never been aggregated in the first place.  Inverse transition
     * functions may optionally return NULL, indicating that the function was
     * unable to remove the tuple from aggregation.  If this happens, or if
     * the aggregate doesn't have an inverse transition function at all, we
     * must perform the aggregation all over again for all tuples within the
     * new frame boundaries.
     *
     * If there's any exclusion clause, then we may have to aggregate over a
     * non-contiguous set of rows, so we punt and recalculate for every row.
     * (For some frame end choices, it might be that the frame is always
     * contiguous anyway, but that's an optimization to investigate later.)
     *
     * In many common cases, multiple rows share the same frame and hence the
     * same aggregate value. (In particular, if there's no ORDER BY in a RANGE
     * window, then all rows are peers and so they all have window frame equal
     * to the whole partition.)  We optimize such cases by calculating the
     * aggregate value once when we reach the first row of a peer group, and
     * then returning the saved value for all subsequent rows.
     *
     * 'aggregatedupto' keeps track of the first row that has not yet been
     * accumulated into the aggregate transition values.  Whenever we start a
     * new peer group, we accumulate forward to the end of the peer group.
     */
 
    /*
     * First, update the frame head position.
     *
     * The frame head should never move backwards, and the code below wouldn't
     * cope if it did, so for safety we complain if it does.
     */
    update_frameheadpos(winstate);
    if (winstate->frameheadpos < winstate->aggregatedbase)
        elog(ERROR, "window frame head moved backward");
 
    /*
     * If the frame didn't change compared to the previous row, we can re-use
     * the result values that were previously saved at the bottom of this
     * function.  Since we don't know the current frame's end yet, this is not
     * possible to check for fully.  But if the frame end mode is UNBOUNDED
     * FOLLOWING or CURRENT ROW, no exclusion clause is specified, and the
     * current row lies within the previous row's frame, then the two frames'
     * ends must coincide.  Note that on the first row aggregatedbase ==
     * aggregatedupto, meaning this test must fail, so we don't need to check
     * the "there was no previous row" case explicitly here.
     */
    if (winstate->aggregatedbase == winstate->frameheadpos &&
        (winstate->frameOptions & (FRAMEOPTION_END_UNBOUNDED_FOLLOWING |
                                   FRAMEOPTION_END_CURRENT_ROW)) &&
        !(winstate->frameOptions & FRAMEOPTION_EXCLUSION) &&
        winstate->aggregatedbase <= winstate->currentpos &&
        winstate->aggregatedupto > winstate->currentpos)
    {
        for (i = 0; i < numaggs; i++)
        {
            peraggstate = &winstate->peragg[i];
            wfuncno = peraggstate->wfuncno;
            econtext->ecxt_aggvalues[wfuncno] = peraggstate->resultValue;
            econtext->ecxt_aggnulls[wfuncno] = peraggstate->resultValueIsNull;
        }
        return;
    }
 
    /*----------
     * Initialize restart flags.
     *
     * We restart the aggregation:
     *   - if we're processing the first row in the partition, or
     *   - if the frame's head moved and we cannot use an inverse
     *     transition function, or
     *   - we have an EXCLUSION clause, or
     *   - if the new frame doesn't overlap the old one
     *
     * Note that we don't strictly need to restart in the last case, but if
     * we're going to remove all rows from the aggregation anyway, a restart
     * surely is faster.
     *----------
     */
    numaggs_restart = 0;
    for (i = 0; i < numaggs; i++)
    {
        peraggstate = &winstate->peragg[i];
        if (winstate->currentpos == 0 ||
            (winstate->aggregatedbase != winstate->frameheadpos &&
             !OidIsValid(peraggstate->invtransfn_oid)) ||
            (winstate->frameOptions & FRAMEOPTION_EXCLUSION) ||
            winstate->aggregatedupto <= winstate->frameheadpos)
        {
            peraggstate->restart = true;
            numaggs_restart++;
        }
        else
            peraggstate->restart = false;
    }
 
    /*
     * If we have any possibly-moving aggregates, attempt to advance
     * aggregatedbase to match the frame's head by removing input rows that
     * fell off the top of the frame from the aggregations.  This can fail,
     * i.e. advance_windowaggregate_base() can return false, in which case
     * we'll restart that aggregate below.
     */
    while (numaggs_restart < numaggs &&
           winstate->aggregatedbase < winstate->frameheadpos)
    {
        /*
         * Fetch the next tuple of those being removed. This should never fail
         * as we should have been here before.
         */
        if (!window_gettupleslot(agg_winobj, winstate->aggregatedbase,
                                 temp_slot))
            elog(ERROR, "could not re-fetch previously fetched frame row");
 
        /* Set tuple context for evaluation of aggregate arguments */
        winstate->tmpcontext->ecxt_outertuple = temp_slot;
 
        /*
         * Perform the inverse transition for each aggregate function in the
         * window, unless it has already been marked as needing a restart.
         */
        for (i = 0; i < numaggs; i++)
        {
            bool        ok;
 
            peraggstate = &winstate->peragg[i];
            if (peraggstate->restart)
                continue;
 
            wfuncno = peraggstate->wfuncno;
            ok = advance_windowaggregate_base(winstate,
                                              &winstate->perfunc[wfuncno],
                                              peraggstate);
            if (!ok)
            {
                /* Inverse transition function has failed, must restart */
                peraggstate->restart = true;
                numaggs_restart++;
            }
        }
 
        /* Reset per-input-tuple context after each tuple */
        ResetExprContext(winstate->tmpcontext);
 
        /* And advance the aggregated-row state */
        winstate->aggregatedbase++;
        ExecClearTuple(temp_slot);
    }
 
    /*
     * If we successfully advanced the base rows of all the aggregates,
     * aggregatedbase now equals frameheadpos; but if we failed for any, we
     * must forcibly update aggregatedbase.
     */
    winstate->aggregatedbase = winstate->frameheadpos;
 
    /*
     * If we created a mark pointer for aggregates, keep it pushed up to frame
     * head, so that tuplestore can discard unnecessary rows.
     */
    if (agg_winobj->markptr >= 0)
        WinSetMarkPosition(agg_winobj, winstate->frameheadpos);
 
    /*
     * Now restart the aggregates that require it.
     *
     * We assume that aggregates using the shared context always restart if
     * *any* aggregate restarts, and we may thus clean up the shared
     * aggcontext if that is the case.  Private aggcontexts are reset by
     * initialize_windowaggregate() if their owning aggregate restarts. If we
     * aren't restarting an aggregate, we need to free any previously saved
     * result for it, else we'll leak memory.
     */
    if (numaggs_restart > 0)
        MemoryContextReset(winstate->aggcontext);
    for (i = 0; i < numaggs; i++)
    {
        peraggstate = &winstate->peragg[i];
 
        /* Aggregates using the shared ctx must restart if *any* agg does */
        Assert(peraggstate->aggcontext != winstate->aggcontext ||
               numaggs_restart == 0 ||
               peraggstate->restart);
 
        if (peraggstate->restart)
        {
            wfuncno = peraggstate->wfuncno;
            initialize_windowaggregate(winstate,
                                       &winstate->perfunc[wfuncno],
                                       peraggstate);
        }
        else if (!peraggstate->resultValueIsNull)
        {
            if (!peraggstate->resulttypeByVal)
                pfree(DatumGetPointer(peraggstate->resultValue));
            peraggstate->resultValue = (Datum) 0;
            peraggstate->resultValueIsNull = true;
        }
    }
 
    /*
     * Non-restarted aggregates now contain the rows between aggregatedbase
     * (i.e., frameheadpos) and aggregatedupto, while restarted aggregates
     * contain no rows.  If there are any restarted aggregates, we must thus
     * begin aggregating anew at frameheadpos, otherwise we may simply
     * continue at aggregatedupto.  We must remember the old value of
     * aggregatedupto to know how long to skip advancing non-restarted
     * aggregates.  If we modify aggregatedupto, we must also clear
     * agg_row_slot, per the loop invariant below.
     */
    aggregatedupto_nonrestarted = winstate->aggregatedupto;
    if (numaggs_restart > 0 &&
        winstate->aggregatedupto != winstate->frameheadpos)
    {
        winstate->aggregatedupto = winstate->frameheadpos;
        ExecClearTuple(agg_row_slot);
    }
 
    /*
     * Advance until we reach a row not in frame (or end of partition).
     *
     * Note the loop invariant: agg_row_slot is either empty or holds the row
     * at position aggregatedupto.  We advance aggregatedupto after processing
     * a row.
     */
    for (;;)
    {
        int         ret;
 
        /* Fetch next row if we didn't already */
        if (TupIsNull(agg_row_slot))
        {
            if (!window_gettupleslot(agg_winobj, winstate->aggregatedupto,
                                     agg_row_slot))
                break;          /* must be end of partition */
        }
 
        /*
         * Exit loop if no more rows can be in frame.  Skip aggregation if
         * current row is not in frame but there might be more in the frame.
         */
        ret = row_is_in_frame(winstate, winstate->aggregatedupto, agg_row_slot);
        if (ret < 0)
            break;
        if (ret == 0)
            goto next_tuple;
 
        /* Set tuple context for evaluation of aggregate arguments */
        winstate->tmpcontext->ecxt_outertuple = agg_row_slot;
 
        /* Accumulate row into the aggregates */
        for (i = 0; i < numaggs; i++)
        {
            peraggstate = &winstate->peragg[i];
 
            /* Non-restarted aggs skip until aggregatedupto_nonrestarted */
            if (!peraggstate->restart &&
                winstate->aggregatedupto < aggregatedupto_nonrestarted)
                continue;
 
            wfuncno = peraggstate->wfuncno;
            advance_windowaggregate(winstate,
                                    &winstate->perfunc[wfuncno],
                                    peraggstate);
        }
 
next_tuple:
        /* Reset per-input-tuple context after each tuple */
        ResetExprContext(winstate->tmpcontext);
 
        /* And advance the aggregated-row state */
        winstate->aggregatedupto++;
        ExecClearTuple(agg_row_slot);
    }
 
    /* The frame's end is not supposed to move backwards, ever */
    Assert(aggregatedupto_nonrestarted <= winstate->aggregatedupto);
 
    /*
     * finalize aggregates and fill result/isnull fields.
     */
    for (i = 0; i < numaggs; i++)
    {
        Datum      *result;
        bool       *isnull;
 
        peraggstate = &winstate->peragg[i];
        wfuncno = peraggstate->wfuncno;
        result = &econtext->ecxt_aggvalues[wfuncno];
        isnull = &econtext->ecxt_aggnulls[wfuncno];
        finalize_windowaggregate(winstate,
                                 &winstate->perfunc[wfuncno],
                                 peraggstate,
                                 result, isnull);
 
        /*
         * save the result in case next row shares the same frame.
         *
         * XXX in some framing modes, eg ROWS/END_CURRENT_ROW, we can know in
         * advance that the next row can't possibly share the same frame. Is
         * it worth detecting that and skipping this code?
         */
        if (!peraggstate->resulttypeByVal && !*isnull)
        {
            oldContext = MemoryContextSwitchTo(peraggstate->aggcontext);
            peraggstate->resultValue =
                datumCopy(*result,
                          peraggstate->resulttypeByVal,
                          peraggstate->resulttypeLen);
            MemoryContextSwitchTo(oldContext);
        }
        else
        {
            peraggstate->resultValue = *result;
        }
        peraggstate->resultValueIsNull = *isnull;
    }
}

Referenced by ExecWindowAgg().

◆ eval_windowfunction()

static void eval_windowfunction	(	WindowAggState *	winstate,
		WindowStatePerFunc	perfuncstate,
		Datum *	result,
		bool *	isnull
	)

static

Definition at line 1033 of file nodeWindowAgg.c.

{
    LOCAL_FCINFO(fcinfo, FUNC_MAX_ARGS);
    MemoryContext oldContext;
 
    oldContext = MemoryContextSwitchTo(winstate->ss.ps.ps_ExprContext->ecxt_per_tuple_memory);
 
    /*
     * We don't pass any normal arguments to a window function, but we do pass
     * it the number of arguments, in order to permit window function
     * implementations to support varying numbers of arguments.  The real info
     * goes through the WindowObject, which is passed via fcinfo->context.
     */
    InitFunctionCallInfoData(*fcinfo, &(perfuncstate->flinfo),
                             perfuncstate->numArguments,
                             perfuncstate->winCollation,
                             (Node *) perfuncstate->winobj, NULL);
    /* Just in case, make all the regular argument slots be null */
    for (int argno = 0; argno < perfuncstate->numArguments; argno++)
        fcinfo->args[argno].isnull = true;
    /* Window functions don't have a current aggregate context, either */
    winstate->curaggcontext = NULL;
 
    *result = FunctionCallInvoke(fcinfo);
    *isnull = fcinfo->isnull;
 
    /*
     * The window function might have returned a pass-by-ref result that's
     * just a pointer into one of the WindowObject's temporary slots.  That's
     * not a problem if it's the only window function using the WindowObject;
     * but if there's more than one function, we'd better copy the result to
     * ensure it's not clobbered by later window functions.
     */
    if (!perfuncstate->resulttypeByVal && !fcinfo->isnull &&
        winstate->numfuncs > 1)
        *result = datumCopy(*result,
                            perfuncstate->resulttypeByVal,
                            perfuncstate->resulttypeLen);
 
    MemoryContextSwitchTo(oldContext);
}

References WindowAggState::curaggcontext, datumCopy(), ExprContext::ecxt_per_tuple_memory, WindowStatePerFuncData::flinfo, FUNC_MAX_ARGS, FunctionCallInvoke, InitFunctionCallInfoData, LOCAL_FCINFO, MemoryContextSwitchTo(), WindowStatePerFuncData::numArguments, WindowAggState::numfuncs, ScanState::ps, PlanState::ps_ExprContext, WindowStatePerFuncData::resulttypeByVal, WindowStatePerFuncData::resulttypeLen, WindowAggState::ss, WindowStatePerFuncData::winCollation, and WindowStatePerFuncData::winobj.

Referenced by ExecWindowAgg().

◆ ExecEndWindowAgg()

void ExecEndWindowAgg ( WindowAggState * node )

Definition at line 2739 of file nodeWindowAgg.c.

{
    PlanState  *outerPlan;
    int         i;
 
    if (node->buffer != NULL)
    {
        tuplestore_end(node->buffer);
 
        /* nullify so that release_partition skips the tuplestore_clear() */
        node->buffer = NULL;
    }
 
    release_partition(node);
 
    for (i = 0; i < node->numaggs; i++)
    {
        if (node->peragg[i].aggcontext != node->aggcontext)
            MemoryContextDelete(node->peragg[i].aggcontext);
    }
    MemoryContextDelete(node->partcontext);
    MemoryContextDelete(node->aggcontext);
 
    pfree(node->perfunc);
    pfree(node->peragg);
 
    outerPlan = outerPlanState(node);
    ExecEndNode(outerPlan);
}

References WindowStatePerAggData::aggcontext, WindowAggState::aggcontext, WindowAggState::buffer, ExecEndNode(), i, MemoryContextDelete(), WindowAggState::numaggs, outerPlan, outerPlanState, WindowAggState::partcontext, WindowAggState::peragg, WindowAggState::perfunc, pfree(), release_partition(), and tuplestore_end().

Referenced by ExecEndNode().

◆ ExecInitWindowAgg()

WindowAggState * ExecInitWindowAgg	(	WindowAgg *	node,
		EState *	estate,
		int	eflags
	)

Definition at line 2431 of file nodeWindowAgg.c.

{
    WindowAggState *winstate;
    Plan       *outerPlan;
    ExprContext *econtext;
    ExprContext *tmpcontext;
    WindowStatePerFunc perfunc;
    WindowStatePerAgg peragg;
    int         frameOptions = node->frameOptions;
    int         numfuncs,
                wfuncno,
                numaggs,
                aggno;
    TupleDesc   scanDesc;
    ListCell   *l;
 
    /* check for unsupported flags */
    Assert(!(eflags & (EXEC_FLAG_BACKWARD | EXEC_FLAG_MARK)));
 
    /*
     * create state structure
     */
    winstate = makeNode(WindowAggState);
    winstate->ss.ps.plan = (Plan *) node;
    winstate->ss.ps.state = estate;
    winstate->ss.ps.ExecProcNode = ExecWindowAgg;
 
    /* copy frame options to state node for easy access */
    winstate->frameOptions = frameOptions;
 
    /*
     * Create expression contexts.  We need two, one for per-input-tuple
     * processing and one for per-output-tuple processing.  We cheat a little
     * by using ExecAssignExprContext() to build both.
     */
    ExecAssignExprContext(estate, &winstate->ss.ps);
    tmpcontext = winstate->ss.ps.ps_ExprContext;
    winstate->tmpcontext = tmpcontext;
    ExecAssignExprContext(estate, &winstate->ss.ps);
 
    /* Create long-lived context for storage of partition-local memory etc */
    winstate->partcontext =
        AllocSetContextCreate(CurrentMemoryContext,
                              "WindowAgg Partition",
                              ALLOCSET_DEFAULT_SIZES);
 
    /*
     * Create mid-lived context for aggregate trans values etc.
     *
     * Note that moving aggregates each use their own private context, not
     * this one.
     */
    winstate->aggcontext =
        AllocSetContextCreate(CurrentMemoryContext,
                              "WindowAgg Aggregates",
                              ALLOCSET_DEFAULT_SIZES);
 
    /* Only the top-level WindowAgg may have a qual */
    Assert(node->plan.qual == NIL || node->topWindow);
 
    /* Initialize the qual */
    winstate->ss.ps.qual = ExecInitQual(node->plan.qual,
                                        (PlanState *) winstate);
 
    /*
     * Setup the run condition, if we received one from the query planner.
     * When set, this may allow us to move into pass-through mode so that we
     * don't have to perform any further evaluation of WindowFuncs in the
     * current partition or possibly stop returning tuples altogether when all
     * tuples are in the same partition.
     */
    winstate->runcondition = ExecInitQual(node->runCondition,
                                          (PlanState *) winstate);
 
    /*
     * When we're not the top-level WindowAgg node or we are but have a
     * PARTITION BY clause we must move into one of the WINDOWAGG_PASSTHROUGH*
     * modes when the runCondition becomes false.
     */
    winstate->use_pass_through = !node->topWindow || node->partNumCols > 0;
 
    /* remember if we're the top-window or we are below the top-window */
    winstate->top_window = node->topWindow;
 
    /*
     * initialize child nodes
     */
    outerPlan = outerPlan(node);
    outerPlanState(winstate) = ExecInitNode(outerPlan, estate, eflags);
 
    /*
     * initialize source tuple type (which is also the tuple type that we'll
     * store in the tuplestore and use in all our working slots).
     */
    ExecCreateScanSlotFromOuterPlan(estate, &winstate->ss, &TTSOpsMinimalTuple);
    scanDesc = winstate->ss.ss_ScanTupleSlot->tts_tupleDescriptor;
 
    /* the outer tuple isn't the child's tuple, but always a minimal tuple */
    winstate->ss.ps.outeropsset = true;
    winstate->ss.ps.outerops = &TTSOpsMinimalTuple;
    winstate->ss.ps.outeropsfixed = true;
 
    /*
     * tuple table initialization
     */
    winstate->first_part_slot = ExecInitExtraTupleSlot(estate, scanDesc,
                                                       &TTSOpsMinimalTuple);
    winstate->agg_row_slot = ExecInitExtraTupleSlot(estate, scanDesc,
                                                    &TTSOpsMinimalTuple);
    winstate->temp_slot_1 = ExecInitExtraTupleSlot(estate, scanDesc,
                                                   &TTSOpsMinimalTuple);
    winstate->temp_slot_2 = ExecInitExtraTupleSlot(estate, scanDesc,
                                                   &TTSOpsMinimalTuple);
 
    /*
     * create frame head and tail slots only if needed (must create slots in
     * exactly the same cases that update_frameheadpos and update_frametailpos
     * need them)
     */
    winstate->framehead_slot = winstate->frametail_slot = NULL;
 
    if (frameOptions & (FRAMEOPTION_RANGE | FRAMEOPTION_GROUPS))
    {
        if (((frameOptions & FRAMEOPTION_START_CURRENT_ROW) &&
             node->ordNumCols != 0) ||
            (frameOptions & FRAMEOPTION_START_OFFSET))
            winstate->framehead_slot = ExecInitExtraTupleSlot(estate, scanDesc,
                                                              &TTSOpsMinimalTuple);
        if (((frameOptions & FRAMEOPTION_END_CURRENT_ROW) &&
             node->ordNumCols != 0) ||
            (frameOptions & FRAMEOPTION_END_OFFSET))
            winstate->frametail_slot = ExecInitExtraTupleSlot(estate, scanDesc,
                                                              &TTSOpsMinimalTuple);
    }
 
    /*
     * Initialize result slot, type and projection.
     */
    ExecInitResultTupleSlotTL(&winstate->ss.ps, &TTSOpsVirtual);
    ExecAssignProjectionInfo(&winstate->ss.ps, NULL);
 
    /* Set up data for comparing tuples */
    if (node->partNumCols > 0)
        winstate->partEqfunction =
            execTuplesMatchPrepare(scanDesc,
                                   node->partNumCols,
                                   node->partColIdx,
                                   node->partOperators,
                                   node->partCollations,
                                   &winstate->ss.ps);
 
    if (node->ordNumCols > 0)
        winstate->ordEqfunction =
            execTuplesMatchPrepare(scanDesc,
                                   node->ordNumCols,
                                   node->ordColIdx,
                                   node->ordOperators,
                                   node->ordCollations,
                                   &winstate->ss.ps);
 
    /*
     * WindowAgg nodes use aggvalues and aggnulls as well as Agg nodes.
     */
    numfuncs = winstate->numfuncs;
    numaggs = winstate->numaggs;
    econtext = winstate->ss.ps.ps_ExprContext;
    econtext->ecxt_aggvalues = (Datum *) palloc0(sizeof(Datum) * numfuncs);
    econtext->ecxt_aggnulls = (bool *) palloc0(sizeof(bool) * numfuncs);
 
    /*
     * allocate per-wfunc/per-agg state information.
     */
    perfunc = (WindowStatePerFunc) palloc0(sizeof(WindowStatePerFuncData) * numfuncs);
    peragg = (WindowStatePerAgg) palloc0(sizeof(WindowStatePerAggData) * numaggs);
    winstate->perfunc = perfunc;
    winstate->peragg = peragg;
 
    wfuncno = -1;
    aggno = -1;
    foreach(l, winstate->funcs)
    {
        WindowFuncExprState *wfuncstate = (WindowFuncExprState *) lfirst(l);
        WindowFunc *wfunc = wfuncstate->wfunc;
        WindowStatePerFunc perfuncstate;
        AclResult   aclresult;
        int         i;
 
        if (wfunc->winref != node->winref)  /* planner screwed up? */
            elog(ERROR, "WindowFunc with winref %u assigned to WindowAgg with winref %u",
                 wfunc->winref, node->winref);
 
        /* Look for a previous duplicate window function */
        for (i = 0; i <= wfuncno; i++)
        {
            if (equal(wfunc, perfunc[i].wfunc) &&
                !contain_volatile_functions((Node *) wfunc))
                break;
        }
        if (i <= wfuncno)
        {
            /* Found a match to an existing entry, so just mark it */
            wfuncstate->wfuncno = i;
            continue;
        }
 
        /* Nope, so assign a new PerAgg record */
        perfuncstate = &perfunc[++wfuncno];
 
        /* Mark WindowFunc state node with assigned index in the result array */
        wfuncstate->wfuncno = wfuncno;
 
        /* Check permission to call window function */
        aclresult = object_aclcheck(ProcedureRelationId, wfunc->winfnoid, GetUserId(),
                                    ACL_EXECUTE);
        if (aclresult != ACLCHECK_OK)
            aclcheck_error(aclresult, OBJECT_FUNCTION,
                           get_func_name(wfunc->winfnoid));
        InvokeFunctionExecuteHook(wfunc->winfnoid);
 
        /* Fill in the perfuncstate data */
        perfuncstate->wfuncstate = wfuncstate;
        perfuncstate->wfunc = wfunc;
        perfuncstate->numArguments = list_length(wfuncstate->args);
        perfuncstate->winCollation = wfunc->inputcollid;
 
        get_typlenbyval(wfunc->wintype,
                        &perfuncstate->resulttypeLen,
                        &perfuncstate->resulttypeByVal);
 
        /*
         * If it's really just a plain aggregate function, we'll emulate the
         * Agg environment for it.
         */
        perfuncstate->plain_agg = wfunc->winagg;
        if (wfunc->winagg)
        {
            WindowStatePerAgg peraggstate;
 
            perfuncstate->aggno = ++aggno;
            peraggstate = &winstate->peragg[aggno];
            initialize_peragg(winstate, wfunc, peraggstate);
            peraggstate->wfuncno = wfuncno;
        }
        else
        {
            WindowObject winobj = makeNode(WindowObjectData);
 
            winobj->winstate = winstate;
            winobj->argstates = wfuncstate->args;
            winobj->localmem = NULL;
            perfuncstate->winobj = winobj;
 
            /* It's a real window function, so set up to call it. */
            fmgr_info_cxt(wfunc->winfnoid, &perfuncstate->flinfo,
                          econtext->ecxt_per_query_memory);
            fmgr_info_set_expr((Node *) wfunc, &perfuncstate->flinfo);
        }
    }
 
    /* Update numfuncs, numaggs to match number of unique functions found */
    winstate->numfuncs = wfuncno + 1;
    winstate->numaggs = aggno + 1;
 
    /* Set up WindowObject for aggregates, if needed */
    if (winstate->numaggs > 0)
    {
        WindowObject agg_winobj = makeNode(WindowObjectData);
 
        agg_winobj->winstate = winstate;
        agg_winobj->argstates = NIL;
        agg_winobj->localmem = NULL;
        /* make sure markptr = -1 to invalidate. It may not get used */
        agg_winobj->markptr = -1;
        agg_winobj->readptr = -1;
        winstate->agg_winobj = agg_winobj;
    }
 
    /* Set the status to running */
    winstate->status = WINDOWAGG_RUN;
 
    /* initialize frame bound offset expressions */
    winstate->startOffset = ExecInitExpr((Expr *) node->startOffset,
                                         (PlanState *) winstate);
    winstate->endOffset = ExecInitExpr((Expr *) node->endOffset,
                                       (PlanState *) winstate);
 
    /* Lookup in_range support functions if needed */
    if (OidIsValid(node->startInRangeFunc))
        fmgr_info(node->startInRangeFunc, &winstate->startInRangeFunc);
    if (OidIsValid(node->endInRangeFunc))
        fmgr_info(node->endInRangeFunc, &winstate->endInRangeFunc);
    winstate->inRangeColl = node->inRangeColl;
    winstate->inRangeAsc = node->inRangeAsc;
    winstate->inRangeNullsFirst = node->inRangeNullsFirst;
 
    winstate->all_first = true;
    winstate->partition_spooled = false;
    winstate->more_partitions = false;
    winstate->next_partition = true;
 
    return winstate;
}

References ACL_EXECUTE, aclcheck_error(), ACLCHECK_OK, WindowAggState::agg_row_slot, WindowAggState::agg_winobj, WindowAggState::aggcontext, WindowStatePerFuncData::aggno, WindowAggState::all_first, ALLOCSET_DEFAULT_SIZES, AllocSetContextCreate, WindowFuncExprState::args, WindowObjectData::argstates, Assert(), contain_volatile_functions(), CurrentMemoryContext, ExprContext::ecxt_aggnulls, ExprContext::ecxt_aggvalues, ExprContext::ecxt_per_query_memory, elog, WindowAggState::endInRangeFunc, WindowAgg::endInRangeFunc, WindowAggState::endOffset, WindowAgg::endOffset, equal(), ERROR, EXEC_FLAG_BACKWARD, EXEC_FLAG_MARK, ExecAssignExprContext(), ExecAssignProjectionInfo(), ExecCreateScanSlotFromOuterPlan(), ExecInitExpr(), ExecInitExtraTupleSlot(), ExecInitNode(), ExecInitQual(), ExecInitResultTupleSlotTL(), PlanState::ExecProcNode, execTuplesMatchPrepare(), ExecWindowAgg(), WindowAggState::first_part_slot, WindowStatePerFuncData::flinfo, fmgr_info(), fmgr_info_cxt(), fmgr_info_set_expr, WindowAggState::framehead_slot, FRAMEOPTION_END_CURRENT_ROW, FRAMEOPTION_END_OFFSET, FRAMEOPTION_GROUPS, FRAMEOPTION_RANGE, FRAMEOPTION_START_CURRENT_ROW, FRAMEOPTION_START_OFFSET, WindowAggState::frameOptions, WindowAgg::frameOptions, WindowAggState::frametail_slot, WindowAggState::funcs, get_func_name(), get_typlenbyval(), GetUserId(), i, initialize_peragg(), WindowAggState::inRangeAsc, WindowAgg::inRangeAsc, WindowAggState::inRangeColl, WindowAgg::inRangeColl, WindowAggState::inRangeNullsFirst, WindowAgg::inRangeNullsFirst, InvokeFunctionExecuteHook, lfirst, list_length(), WindowObjectData::localmem, makeNode, WindowObjectData::markptr, WindowAggState::more_partitions, WindowAggState::next_partition, NIL, WindowAggState::numaggs, WindowStatePerFuncData::numArguments, WindowAggState::numfuncs, object_aclcheck(), OBJECT_FUNCTION, OidIsValid, WindowAggState::ordEqfunction, WindowAgg::ordNumCols, PlanState::outerops, PlanState::outeropsfixed, PlanState::outeropsset, outerPlan, outerPlanState, palloc0(), WindowAggState::partcontext, WindowAggState::partEqfunction, WindowAggState::partition_spooled, WindowAgg::partNumCols, WindowAggState::peragg, WindowAggState::perfunc, WindowStatePerFuncData::plain_agg, PlanState::plan, WindowAgg::plan, ScanState::ps, PlanState::ps_ExprContext, PlanState::qual, Plan::qual, WindowObjectData::readptr, WindowStatePerFuncData::resulttypeByVal, WindowStatePerFuncData::resulttypeLen, WindowAggState::runcondition, WindowAgg::runCondition, WindowAggState::ss, ScanState::ss_ScanTupleSlot, WindowAggState::startInRangeFunc, WindowAgg::startInRangeFunc, WindowAggState::startOffset, WindowAgg::startOffset, PlanState::state, WindowAggState::status, WindowAggState::temp_slot_1, WindowAggState::temp_slot_2, WindowAggState::tmpcontext, WindowAggState::top_window, WindowAgg::topWindow, TupleTableSlot::tts_tupleDescriptor, TTSOpsMinimalTuple, TTSOpsVirtual, WindowAggState::use_pass_through, WindowStatePerFuncData::wfunc, WindowFuncExprState::wfunc, WindowStatePerAggData::wfuncno, WindowFuncExprState::wfuncno, WindowStatePerFuncData::wfuncstate, WindowStatePerFuncData::winCollation, WINDOWAGG_RUN, WindowFunc::winfnoid, WindowStatePerFuncData::winobj, WindowAgg::winref, WindowFunc::winref, and WindowObjectData::winstate.

Referenced by ExecInitNode().

◆ ExecReScanWindowAgg()

void ExecReScanWindowAgg ( WindowAggState * node )

Definition at line 2774 of file nodeWindowAgg.c.

{
    PlanState  *outerPlan = outerPlanState(node);
    ExprContext *econtext = node->ss.ps.ps_ExprContext;
 
    node->status = WINDOWAGG_RUN;
    node->all_first = true;
 
    /* release tuplestore et al */
    release_partition(node);
 
    /* release all temp tuples, but especially first_part_slot */
    ExecClearTuple(node->ss.ss_ScanTupleSlot);
    ExecClearTuple(node->first_part_slot);
    ExecClearTuple(node->agg_row_slot);
    ExecClearTuple(node->temp_slot_1);
    ExecClearTuple(node->temp_slot_2);
    if (node->framehead_slot)
        ExecClearTuple(node->framehead_slot);
    if (node->frametail_slot)
        ExecClearTuple(node->frametail_slot);
 
    /* Forget current wfunc values */
    MemSet(econtext->ecxt_aggvalues, 0, sizeof(Datum) * node->numfuncs);
    MemSet(econtext->ecxt_aggnulls, 0, sizeof(bool) * node->numfuncs);
 
    /*
     * if chgParam of subnode is not null then plan will be re-scanned by
     * first ExecProcNode.
     */
    if (outerPlan->chgParam == NULL)
        ExecReScan(outerPlan);
}

References WindowAggState::agg_row_slot, WindowAggState::all_first, ExprContext::ecxt_aggnulls, ExprContext::ecxt_aggvalues, ExecClearTuple(), ExecReScan(), WindowAggState::first_part_slot, WindowAggState::framehead_slot, WindowAggState::frametail_slot, MemSet, WindowAggState::numfuncs, outerPlan, outerPlanState, ScanState::ps, PlanState::ps_ExprContext, release_partition(), WindowAggState::ss, ScanState::ss_ScanTupleSlot, WindowAggState::status, WindowAggState::temp_slot_1, WindowAggState::temp_slot_2, and WINDOWAGG_RUN.

Referenced by ExecReScan().

◆ ExecWindowAgg()

static TupleTableSlot * ExecWindowAgg ( PlanState * pstate )

static

Definition at line 2163 of file nodeWindowAgg.c.

{
    WindowAggState *winstate = castNode(WindowAggState, pstate);
    TupleTableSlot *slot;
    ExprContext *econtext;
    int         i;
    int         numfuncs;
 
    CHECK_FOR_INTERRUPTS();
 
    if (winstate->status == WINDOWAGG_DONE)
        return NULL;
 
    /*
     * Compute frame offset values, if any, during first call (or after a
     * rescan).  These are assumed to hold constant throughout the scan; if
     * user gives us a volatile expression, we'll only use its initial value.
     */
    if (unlikely(winstate->all_first))
        calculate_frame_offsets(pstate);
 
    /* We need to loop as the runCondition or qual may filter out tuples */
    for (;;)
    {
        if (winstate->next_partition)
        {
            /* Initialize for first partition and set current row = 0 */
            begin_partition(winstate);
            /* If there are no input rows, we'll detect that and exit below */
        }
        else
        {
            /* Advance current row within partition */
            winstate->currentpos++;
            /* This might mean that the frame moves, too */
            winstate->framehead_valid = false;
            winstate->frametail_valid = false;
            /* we don't need to invalidate grouptail here; see below */
        }
 
        /*
         * Spool all tuples up to and including the current row, if we haven't
         * already
         */
        spool_tuples(winstate, winstate->currentpos);
 
        /* Move to the next partition if we reached the end of this partition */
        if (winstate->partition_spooled &&
            winstate->currentpos >= winstate->spooled_rows)
        {
            release_partition(winstate);
 
            if (winstate->more_partitions)
            {
                begin_partition(winstate);
                Assert(winstate->spooled_rows > 0);
 
                /* Come out of pass-through mode when changing partition */
                winstate->status = WINDOWAGG_RUN;
            }
            else
            {
                /* No further partitions?  We're done */
                winstate->status = WINDOWAGG_DONE;
                return NULL;
            }
        }
 
        /* final output execution is in ps_ExprContext */
        econtext = winstate->ss.ps.ps_ExprContext;
 
        /* Clear the per-output-tuple context for current row */
        ResetExprContext(econtext);
 
        /*
         * Read the current row from the tuplestore, and save in
         * ScanTupleSlot. (We can't rely on the outerplan's output slot
         * because we may have to read beyond the current row.  Also, we have
         * to actually copy the row out of the tuplestore, since window
         * function evaluation might cause the tuplestore to dump its state to
         * disk.)
         *
         * In GROUPS mode, or when tracking a group-oriented exclusion clause,
         * we must also detect entering a new peer group and update associated
         * state when that happens.  We use temp_slot_2 to temporarily hold
         * the previous row for this purpose.
         *
         * Current row must be in the tuplestore, since we spooled it above.
         */
        tuplestore_select_read_pointer(winstate->buffer, winstate->current_ptr);
        if ((winstate->frameOptions & (FRAMEOPTION_GROUPS |
                                       FRAMEOPTION_EXCLUDE_GROUP |
                                       FRAMEOPTION_EXCLUDE_TIES)) &&
            winstate->currentpos > 0)
        {
            ExecCopySlot(winstate->temp_slot_2, winstate->ss.ss_ScanTupleSlot);
            if (!tuplestore_gettupleslot(winstate->buffer, true, true,
                                         winstate->ss.ss_ScanTupleSlot))
                elog(ERROR, "unexpected end of tuplestore");
            if (!are_peers(winstate, winstate->temp_slot_2,
                           winstate->ss.ss_ScanTupleSlot))
            {
                winstate->currentgroup++;
                winstate->groupheadpos = winstate->currentpos;
                winstate->grouptail_valid = false;
            }
            ExecClearTuple(winstate->temp_slot_2);
        }
        else
        {
            if (!tuplestore_gettupleslot(winstate->buffer, true, true,
                                         winstate->ss.ss_ScanTupleSlot))
                elog(ERROR, "unexpected end of tuplestore");
        }
 
        /* don't evaluate the window functions when we're in pass-through mode */
        if (winstate->status == WINDOWAGG_RUN)
        {
            /*
             * Evaluate true window functions
             */
            numfuncs = winstate->numfuncs;
            for (i = 0; i < numfuncs; i++)
            {
                WindowStatePerFunc perfuncstate = &(winstate->perfunc[i]);
 
                if (perfuncstate->plain_agg)
                    continue;
                eval_windowfunction(winstate, perfuncstate,
                                    &(econtext->ecxt_aggvalues[perfuncstate->wfuncstate->wfuncno]),
                                    &(econtext->ecxt_aggnulls[perfuncstate->wfuncstate->wfuncno]));
            }
 
            /*
             * Evaluate aggregates
             */
            if (winstate->numaggs > 0)
                eval_windowaggregates(winstate);
        }
 
        /*
         * If we have created auxiliary read pointers for the frame or group
         * boundaries, force them to be kept up-to-date, because we don't know
         * whether the window function(s) will do anything that requires that.
         * Failing to advance the pointers would result in being unable to
         * trim data from the tuplestore, which is bad.  (If we could know in
         * advance whether the window functions will use frame boundary info,
         * we could skip creating these pointers in the first place ... but
         * unfortunately the window function API doesn't require that.)
         */
        if (winstate->framehead_ptr >= 0)
            update_frameheadpos(winstate);
        if (winstate->frametail_ptr >= 0)
            update_frametailpos(winstate);
        if (winstate->grouptail_ptr >= 0)
            update_grouptailpos(winstate);
 
        /*
         * Truncate any no-longer-needed rows from the tuplestore.
         */
        tuplestore_trim(winstate->buffer);
 
        /*
         * Form and return a projection tuple using the windowfunc results and
         * the current row.  Setting ecxt_outertuple arranges that any Vars
         * will be evaluated with respect to that row.
         */
        econtext->ecxt_outertuple = winstate->ss.ss_ScanTupleSlot;
 
        slot = ExecProject(winstate->ss.ps.ps_ProjInfo);
 
        if (winstate->status == WINDOWAGG_RUN)
        {
            econtext->ecxt_scantuple = slot;
 
            /*
             * Now evaluate the run condition to see if we need to go into
             * pass-through mode, or maybe stop completely.
             */
            if (!ExecQual(winstate->runcondition, econtext))
            {
                /*
                 * Determine which mode to move into.  If there is no
                 * PARTITION BY clause and we're the top-level WindowAgg then
                 * we're done.  This tuple and any future tuples cannot
                 * possibly match the runcondition.  However, when there is a
                 * PARTITION BY clause or we're not the top-level window we
                 * can't just stop as we need to either process other
                 * partitions or ensure WindowAgg nodes above us receive all
                 * of the tuples they need to process their WindowFuncs.
                 */
                if (winstate->use_pass_through)
                {
                    /*
                     * When switching into a pass-through mode, we'd better
                     * NULLify the aggregate results as these are no longer
                     * updated and NULLifying them avoids the old stale
                     * results lingering.  Some of these might be byref types
                     * so we can't have them pointing to free'd memory.  The
                     * planner insisted that quals used in the runcondition
                     * are strict, so the top-level WindowAgg will always
                     * filter these NULLs out in the filter clause.
                     */
                    numfuncs = winstate->numfuncs;
                    for (i = 0; i < numfuncs; i++)
                    {
                        econtext->ecxt_aggvalues[i] = (Datum) 0;
                        econtext->ecxt_aggnulls[i] = true;
                    }
 
                    /*
                     * STRICT pass-through mode is required for the top window
                     * when there is a PARTITION BY clause.  Otherwise we must
                     * ensure we store tuples that don't match the
                     * runcondition so they're available to WindowAggs above.
                     */
                    if (winstate->top_window)
                    {
                        winstate->status = WINDOWAGG_PASSTHROUGH_STRICT;
                        continue;
                    }
                    else
                    {
                        winstate->status = WINDOWAGG_PASSTHROUGH;
                    }
                }
                else
                {
                    /*
                     * Pass-through not required.  We can just return NULL.
                     * Nothing else will match the runcondition.
                     */
                    winstate->status = WINDOWAGG_DONE;
                    return NULL;
                }
            }
 
            /*
             * Filter out any tuples we don't need in the top-level WindowAgg.
             */
            if (!ExecQual(winstate->ss.ps.qual, econtext))
            {
                InstrCountFiltered1(winstate, 1);
                continue;
            }
 
            break;
        }
 
        /*
         * When not in WINDOWAGG_RUN mode, we must still return this tuple if
         * we're anything apart from the top window.
         */
        else if (!winstate->top_window)
            break;
    }
 
    return slot;
}

References WindowAggState::all_first, are_peers(), Assert(), begin_partition(), WindowAggState::buffer, calculate_frame_offsets(), castNode, CHECK_FOR_INTERRUPTS, WindowAggState::current_ptr, WindowAggState::currentgroup, WindowAggState::currentpos, ExprContext::ecxt_aggnulls, ExprContext::ecxt_aggvalues, ExprContext::ecxt_outertuple, ExprContext::ecxt_scantuple, elog, ERROR, eval_windowaggregates(), eval_windowfunction(), ExecClearTuple(), ExecCopySlot(), ExecProject(), ExecQual(), WindowAggState::framehead_ptr, WindowAggState::framehead_valid, FRAMEOPTION_EXCLUDE_GROUP, FRAMEOPTION_EXCLUDE_TIES, FRAMEOPTION_GROUPS, WindowAggState::frameOptions, WindowAggState::frametail_ptr, WindowAggState::frametail_valid, WindowAggState::groupheadpos, WindowAggState::grouptail_ptr, WindowAggState::grouptail_valid, i, InstrCountFiltered1, WindowAggState::more_partitions, WindowAggState::next_partition, WindowAggState::numaggs, WindowAggState::numfuncs, WindowAggState::partition_spooled, WindowAggState::perfunc, WindowStatePerFuncData::plain_agg, ScanState::ps, PlanState::ps_ExprContext, PlanState::ps_ProjInfo, PlanState::qual, release_partition(), ResetExprContext, WindowAggState::runcondition, spool_tuples(), WindowAggState::spooled_rows, WindowAggState::ss, ScanState::ss_ScanTupleSlot, WindowAggState::status, WindowAggState::temp_slot_2, WindowAggState::top_window, tuplestore_gettupleslot(), tuplestore_select_read_pointer(), tuplestore_trim(), unlikely, update_frameheadpos(), update_frametailpos(), update_grouptailpos(), WindowAggState::use_pass_through, WindowFuncExprState::wfuncno, WindowStatePerFuncData::wfuncstate, WINDOWAGG_DONE, WINDOWAGG_PASSTHROUGH, WINDOWAGG_PASSTHROUGH_STRICT, and WINDOWAGG_RUN.

Referenced by ExecInitWindowAgg().

◆ finalize_windowaggregate()

static void finalize_windowaggregate	(	WindowAggState *	winstate,
		WindowStatePerFunc	perfuncstate,
		WindowStatePerAgg	peraggstate,
		Datum *	result,
		bool *	isnull
	)

static

Definition at line 582 of file nodeWindowAgg.c.

{
    MemoryContext oldContext;
 
    oldContext = MemoryContextSwitchTo(winstate->ss.ps.ps_ExprContext->ecxt_per_tuple_memory);
 
    /*
     * Apply the agg's finalfn if one is provided, else return transValue.
     */
    if (OidIsValid(peraggstate->finalfn_oid))
    {
        LOCAL_FCINFO(fcinfo, FUNC_MAX_ARGS);
        int         numFinalArgs = peraggstate->numFinalArgs;
        bool        anynull;
        int         i;
 
        InitFunctionCallInfoData(fcinfodata.fcinfo, &(peraggstate->finalfn),
                                 numFinalArgs,
                                 perfuncstate->winCollation,
                                 (Node *) winstate, NULL);
        fcinfo->args[0].value =
            MakeExpandedObjectReadOnly(peraggstate->transValue,
                                       peraggstate->transValueIsNull,
                                       peraggstate->transtypeLen);
        fcinfo->args[0].isnull = peraggstate->transValueIsNull;
        anynull = peraggstate->transValueIsNull;
 
        /* Fill any remaining argument positions with nulls */
        for (i = 1; i < numFinalArgs; i++)
        {
            fcinfo->args[i].value = (Datum) 0;
            fcinfo->args[i].isnull = true;
            anynull = true;
        }
 
        if (fcinfo->flinfo->fn_strict && anynull)
        {
            /* don't call a strict function with NULL inputs */
            *result = (Datum) 0;
            *isnull = true;
        }
        else
        {
            Datum       res;
 
            winstate->curaggcontext = peraggstate->aggcontext;
            res = FunctionCallInvoke(fcinfo);
            winstate->curaggcontext = NULL;
            *isnull = fcinfo->isnull;
            *result = MakeExpandedObjectReadOnly(res,
                                                 fcinfo->isnull,
                                                 peraggstate->resulttypeLen);
        }
    }
    else
    {
        *result =
            MakeExpandedObjectReadOnly(peraggstate->transValue,
                                       peraggstate->transValueIsNull,
                                       peraggstate->transtypeLen);
        *isnull = peraggstate->transValueIsNull;
    }
 
    MemoryContextSwitchTo(oldContext);
}

References WindowStatePerAggData::aggcontext, ExprContext::ecxt_per_tuple_memory, WindowStatePerAggData::finalfn, WindowStatePerAggData::finalfn_oid, FUNC_MAX_ARGS, FunctionCallInvoke, i, InitFunctionCallInfoData, LOCAL_FCINFO, MakeExpandedObjectReadOnly, MemoryContextSwitchTo(), WindowStatePerAggData::numFinalArgs, OidIsValid, ScanState::ps, PlanState::ps_ExprContext, WindowStatePerAggData::resulttypeLen, WindowAggState::ss, WindowStatePerAggData::transtypeLen, WindowStatePerAggData::transValue, WindowStatePerAggData::transValueIsNull, and WindowStatePerFuncData::winCollation.

Referenced by eval_windowaggregates().

◆ GetAggInitVal()

static Datum GetAggInitVal	(	Datum	textInitVal,
		Oid	transtype
	)

static

Definition at line 3087 of file nodeWindowAgg.c.

{
    Oid         typinput,
                typioparam;
    char       *strInitVal;
    Datum       initVal;
 
    getTypeInputInfo(transtype, &typinput, &typioparam);
    strInitVal = TextDatumGetCString(textInitVal);
    initVal = OidInputFunctionCall(typinput, strInitVal,
                                   typioparam, -1);
    pfree(strInitVal);
    return initVal;
}

References getTypeInputInfo(), OidInputFunctionCall(), pfree(), and TextDatumGetCString.

Referenced by initialize_peragg().

◆ initialize_peragg()

static WindowStatePerAggData * initialize_peragg	(	WindowAggState *	winstate,
		WindowFunc *	wfunc,
		WindowStatePerAgg	peraggstate
	)

static

Definition at line 2814 of file nodeWindowAgg.c.

{
    Oid         inputTypes[FUNC_MAX_ARGS];
    int         numArguments;
    HeapTuple   aggTuple;
    Form_pg_aggregate aggform;
    Oid         aggtranstype;
    AttrNumber  initvalAttNo;
    AclResult   aclresult;
    bool        use_ma_code;
    Oid         transfn_oid,
                invtransfn_oid,
                finalfn_oid;
    bool        finalextra;
    char        finalmodify;
    Expr       *transfnexpr,
               *invtransfnexpr,
               *finalfnexpr;
    Datum       textInitVal;
    int         i;
    ListCell   *lc;
 
    numArguments = list_length(wfunc->args);
 
    i = 0;
    foreach(lc, wfunc->args)
    {
        inputTypes[i++] = exprType((Node *) lfirst(lc));
    }
 
    aggTuple = SearchSysCache1(AGGFNOID, ObjectIdGetDatum(wfunc->winfnoid));
    if (!HeapTupleIsValid(aggTuple))
        elog(ERROR, "cache lookup failed for aggregate %u",
             wfunc->winfnoid);
    aggform = (Form_pg_aggregate) GETSTRUCT(aggTuple);
 
    /*
     * Figure out whether we want to use the moving-aggregate implementation,
     * and collect the right set of fields from the pg_aggregate entry.
     *
     * It's possible that an aggregate would supply a safe moving-aggregate
     * implementation and an unsafe normal one, in which case our hand is
     * forced.  Otherwise, if the frame head can't move, we don't need
     * moving-aggregate code.  Even if we'd like to use it, don't do so if the
     * aggregate's arguments (and FILTER clause if any) contain any calls to
     * volatile functions.  Otherwise, the difference between restarting and
     * not restarting the aggregation would be user-visible.
     *
     * We also don't risk using moving aggregates when there are subplans in
     * the arguments or FILTER clause.  This is partly because
     * contain_volatile_functions() doesn't look inside subplans; but there
     * are other reasons why a subplan's output might be volatile.  For
     * example, syncscan mode can render the results nonrepeatable.
     */
    if (!OidIsValid(aggform->aggminvtransfn))
        use_ma_code = false;    /* sine qua non */
    else if (aggform->aggmfinalmodify == AGGMODIFY_READ_ONLY &&
             aggform->aggfinalmodify != AGGMODIFY_READ_ONLY)
        use_ma_code = true;     /* decision forced by safety */
    else if (winstate->frameOptions & FRAMEOPTION_START_UNBOUNDED_PRECEDING)
        use_ma_code = false;    /* non-moving frame head */
    else if (contain_volatile_functions((Node *) wfunc))
        use_ma_code = false;    /* avoid possible behavioral change */
    else if (contain_subplans((Node *) wfunc))
        use_ma_code = false;    /* subplans might contain volatile functions */
    else
        use_ma_code = true;     /* yes, let's use it */
    if (use_ma_code)
    {
        peraggstate->transfn_oid = transfn_oid = aggform->aggmtransfn;
        peraggstate->invtransfn_oid = invtransfn_oid = aggform->aggminvtransfn;
        peraggstate->finalfn_oid = finalfn_oid = aggform->aggmfinalfn;
        finalextra = aggform->aggmfinalextra;
        finalmodify = aggform->aggmfinalmodify;
        aggtranstype = aggform->aggmtranstype;
        initvalAttNo = Anum_pg_aggregate_aggminitval;
    }
    else
    {
        peraggstate->transfn_oid = transfn_oid = aggform->aggtransfn;
        peraggstate->invtransfn_oid = invtransfn_oid = InvalidOid;
        peraggstate->finalfn_oid = finalfn_oid = aggform->aggfinalfn;
        finalextra = aggform->aggfinalextra;
        finalmodify = aggform->aggfinalmodify;
        aggtranstype = aggform->aggtranstype;
        initvalAttNo = Anum_pg_aggregate_agginitval;
    }
 
    /*
     * ExecInitWindowAgg already checked permission to call aggregate function
     * ... but we still need to check the component functions
     */
 
    /* Check that aggregate owner has permission to call component fns */
    {
        HeapTuple   procTuple;
        Oid         aggOwner;
 
        procTuple = SearchSysCache1(PROCOID,
                                    ObjectIdGetDatum(wfunc->winfnoid));
        if (!HeapTupleIsValid(procTuple))
            elog(ERROR, "cache lookup failed for function %u",
                 wfunc->winfnoid);
        aggOwner = ((Form_pg_proc) GETSTRUCT(procTuple))->proowner;
        ReleaseSysCache(procTuple);
 
        aclresult = object_aclcheck(ProcedureRelationId, transfn_oid, aggOwner,
                                    ACL_EXECUTE);
        if (aclresult != ACLCHECK_OK)
            aclcheck_error(aclresult, OBJECT_FUNCTION,
                           get_func_name(transfn_oid));
        InvokeFunctionExecuteHook(transfn_oid);
 
        if (OidIsValid(invtransfn_oid))
        {
            aclresult = object_aclcheck(ProcedureRelationId, invtransfn_oid, aggOwner,
                                        ACL_EXECUTE);
            if (aclresult != ACLCHECK_OK)
                aclcheck_error(aclresult, OBJECT_FUNCTION,
                               get_func_name(invtransfn_oid));
            InvokeFunctionExecuteHook(invtransfn_oid);
        }
 
        if (OidIsValid(finalfn_oid))
        {
            aclresult = object_aclcheck(ProcedureRelationId, finalfn_oid, aggOwner,
                                        ACL_EXECUTE);
            if (aclresult != ACLCHECK_OK)
                aclcheck_error(aclresult, OBJECT_FUNCTION,
                               get_func_name(finalfn_oid));
            InvokeFunctionExecuteHook(finalfn_oid);
        }
    }
 
    /*
     * If the selected finalfn isn't read-only, we can't run this aggregate as
     * a window function.  This is a user-facing error, so we take a bit more
     * care with the error message than elsewhere in this function.
     */
    if (finalmodify != AGGMODIFY_READ_ONLY)
        ereport(ERROR,
                (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
                 errmsg("aggregate function %s does not support use as a window function",
                        format_procedure(wfunc->winfnoid))));
 
    /* Detect how many arguments to pass to the finalfn */
    if (finalextra)
        peraggstate->numFinalArgs = numArguments + 1;
    else
        peraggstate->numFinalArgs = 1;
 
    /* resolve actual type of transition state, if polymorphic */
    aggtranstype = resolve_aggregate_transtype(wfunc->winfnoid,
                                               aggtranstype,
                                               inputTypes,
                                               numArguments);
 
    /* build expression trees using actual argument & result types */
    build_aggregate_transfn_expr(inputTypes,
                                 numArguments,
                                 0, /* no ordered-set window functions yet */
                                 false, /* no variadic window functions yet */
                                 aggtranstype,
                                 wfunc->inputcollid,
                                 transfn_oid,
                                 invtransfn_oid,
                                 &transfnexpr,
                                 &invtransfnexpr);
 
    /* set up infrastructure for calling the transfn(s) and finalfn */
    fmgr_info(transfn_oid, &peraggstate->transfn);
    fmgr_info_set_expr((Node *) transfnexpr, &peraggstate->transfn);
 
    if (OidIsValid(invtransfn_oid))
    {
        fmgr_info(invtransfn_oid, &peraggstate->invtransfn);
        fmgr_info_set_expr((Node *) invtransfnexpr, &peraggstate->invtransfn);
    }
 
    if (OidIsValid(finalfn_oid))
    {
        build_aggregate_finalfn_expr(inputTypes,
                                     peraggstate->numFinalArgs,
                                     aggtranstype,
                                     wfunc->wintype,
                                     wfunc->inputcollid,
                                     finalfn_oid,
                                     &finalfnexpr);
        fmgr_info(finalfn_oid, &peraggstate->finalfn);
        fmgr_info_set_expr((Node *) finalfnexpr, &peraggstate->finalfn);
    }
 
    /* get info about relevant datatypes */
    get_typlenbyval(wfunc->wintype,
                    &peraggstate->resulttypeLen,
                    &peraggstate->resulttypeByVal);
    get_typlenbyval(aggtranstype,
                    &peraggstate->transtypeLen,
                    &peraggstate->transtypeByVal);
 
    /*
     * initval is potentially null, so don't try to access it as a struct
     * field. Must do it the hard way with SysCacheGetAttr.
     */
    textInitVal = SysCacheGetAttr(AGGFNOID, aggTuple, initvalAttNo,
                                  &peraggstate->initValueIsNull);
 
    if (peraggstate->initValueIsNull)
        peraggstate->initValue = (Datum) 0;
    else
        peraggstate->initValue = GetAggInitVal(textInitVal,
                                               aggtranstype);
 
    /*
     * If the transfn is strict and the initval is NULL, make sure input type
     * and transtype are the same (or at least binary-compatible), so that
     * it's OK to use the first input value as the initial transValue.  This
     * should have been checked at agg definition time, but we must check
     * again in case the transfn's strictness property has been changed.
     */
    if (peraggstate->transfn.fn_strict && peraggstate->initValueIsNull)
    {
        if (numArguments < 1 ||
            !IsBinaryCoercible(inputTypes[0], aggtranstype))
            ereport(ERROR,
                    (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
                     errmsg("aggregate %u needs to have compatible input type and transition type",
                            wfunc->winfnoid)));
    }
 
    /*
     * Insist that forward and inverse transition functions have the same
     * strictness setting.  Allowing them to differ would require handling
     * more special cases in advance_windowaggregate and
     * advance_windowaggregate_base, for no discernible benefit.  This should
     * have been checked at agg definition time, but we must check again in
     * case either function's strictness property has been changed.
     */
    if (OidIsValid(invtransfn_oid) &&
        peraggstate->transfn.fn_strict != peraggstate->invtransfn.fn_strict)
        ereport(ERROR,
                (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
                 errmsg("strictness of aggregate's forward and inverse transition functions must match")));
 
    /*
     * Moving aggregates use their own aggcontext.
     *
     * This is necessary because they might restart at different times, so we
     * might never be able to reset the shared context otherwise.  We can't
     * make it the aggregates' responsibility to clean up after themselves,
     * because strict aggregates must be restarted whenever we remove their
     * last non-NULL input, which the aggregate won't be aware is happening.
     * Also, just pfree()ing the transValue upon restarting wouldn't help,
     * since we'd miss any indirectly referenced data.  We could, in theory,
     * make the memory allocation rules for moving aggregates different than
     * they have historically been for plain aggregates, but that seems grotty
     * and likely to lead to memory leaks.
     */
    if (OidIsValid(invtransfn_oid))
        peraggstate->aggcontext =
            AllocSetContextCreate(CurrentMemoryContext,
                                  "WindowAgg Per Aggregate",
                                  ALLOCSET_DEFAULT_SIZES);
    else
        peraggstate->aggcontext = winstate->aggcontext;
 
    ReleaseSysCache(aggTuple);
 
    return peraggstate;
}

Referenced by ExecInitWindowAgg().

◆ initialize_windowaggregate()

static void initialize_windowaggregate	(	WindowAggState *	winstate,
		WindowStatePerFunc	perfuncstate,
		WindowStatePerAgg	peraggstate
	)

static

Definition at line 207 of file nodeWindowAgg.c.

{
    MemoryContext oldContext;
 
    /*
     * If we're using a private aggcontext, we may reset it here.  But if the
     * context is shared, we don't know which other aggregates may still need
     * it, so we must leave it to the caller to reset at an appropriate time.
     */
    if (peraggstate->aggcontext != winstate->aggcontext)
        MemoryContextReset(peraggstate->aggcontext);
 
    if (peraggstate->initValueIsNull)
        peraggstate->transValue = peraggstate->initValue;
    else
    {
        oldContext = MemoryContextSwitchTo(peraggstate->aggcontext);
        peraggstate->transValue = datumCopy(peraggstate->initValue,
                                            peraggstate->transtypeByVal,
                                            peraggstate->transtypeLen);
        MemoryContextSwitchTo(oldContext);
    }
    peraggstate->transValueIsNull = peraggstate->initValueIsNull;
    peraggstate->transValueCount = 0;
    peraggstate->resultValue = (Datum) 0;
    peraggstate->resultValueIsNull = true;
}

References WindowStatePerAggData::aggcontext, WindowAggState::aggcontext, datumCopy(), WindowStatePerAggData::initValue, WindowStatePerAggData::initValueIsNull, MemoryContextReset(), MemoryContextSwitchTo(), WindowStatePerAggData::resultValue, WindowStatePerAggData::resultValueIsNull, WindowStatePerAggData::transtypeByVal, WindowStatePerAggData::transtypeLen, WindowStatePerAggData::transValue, WindowStatePerAggData::transValueCount, and WindowStatePerAggData::transValueIsNull.

Referenced by advance_windowaggregate_base(), and eval_windowaggregates().

◆ prepare_tuplestore()

static pg_noinline void prepare_tuplestore ( WindowAggState * winstate )

static

Definition at line 1085 of file nodeWindowAgg.c.

{
    WindowAgg  *node = (WindowAgg *) winstate->ss.ps.plan;
    int         frameOptions = winstate->frameOptions;
    int         numfuncs = winstate->numfuncs;
 
    /* we shouldn't be called if this was done already */
    Assert(winstate->buffer == NULL);
 
    /* Create new tuplestore */
    winstate->buffer = tuplestore_begin_heap(false, false, work_mem);
 
    /*
     * Set up read pointers for the tuplestore.  The current pointer doesn't
     * need BACKWARD capability, but the per-window-function read pointers do,
     * and the aggregate pointer does if we might need to restart aggregation.
     */
    winstate->current_ptr = 0;  /* read pointer 0 is pre-allocated */
 
    /* reset default REWIND capability bit for current ptr */
    tuplestore_set_eflags(winstate->buffer, 0);
 
    /* create read pointers for aggregates, if needed */
    if (winstate->numaggs > 0)
    {
        WindowObject agg_winobj = winstate->agg_winobj;
        int         readptr_flags = 0;
 
        /*
         * If the frame head is potentially movable, or we have an EXCLUSION
         * clause, we might need to restart aggregation ...
         */
        if (!(frameOptions & FRAMEOPTION_START_UNBOUNDED_PRECEDING) ||
            (frameOptions & FRAMEOPTION_EXCLUSION))
        {
            /* ... so create a mark pointer to track the frame head */
            agg_winobj->markptr = tuplestore_alloc_read_pointer(winstate->buffer, 0);
            /* and the read pointer will need BACKWARD capability */
            readptr_flags |= EXEC_FLAG_BACKWARD;
        }
 
        agg_winobj->readptr = tuplestore_alloc_read_pointer(winstate->buffer,
                                                            readptr_flags);
    }
 
    /* create mark and read pointers for each real window function */
    for (int i = 0; i < numfuncs; i++)
    {
        WindowStatePerFunc perfuncstate = &(winstate->perfunc[i]);
 
        if (!perfuncstate->plain_agg)
        {
            WindowObject winobj = perfuncstate->winobj;
 
            winobj->markptr = tuplestore_alloc_read_pointer(winstate->buffer,
                                                            0);
            winobj->readptr = tuplestore_alloc_read_pointer(winstate->buffer,
                                                            EXEC_FLAG_BACKWARD);
        }
    }
 
    /*
     * If we are in RANGE or GROUPS mode, then determining frame boundaries
     * requires physical access to the frame endpoint rows, except in certain
     * degenerate cases.  We create read pointers to point to those rows, to
     * simplify access and ensure that the tuplestore doesn't discard the
     * endpoint rows prematurely.  (Must create pointers in exactly the same
     * cases that update_frameheadpos and update_frametailpos need them.)
     */
    winstate->framehead_ptr = winstate->frametail_ptr = -1; /* if not used */
 
    if (frameOptions & (FRAMEOPTION_RANGE | FRAMEOPTION_GROUPS))
    {
        if (((frameOptions & FRAMEOPTION_START_CURRENT_ROW) &&
             node->ordNumCols != 0) ||
            (frameOptions & FRAMEOPTION_START_OFFSET))
            winstate->framehead_ptr =
                tuplestore_alloc_read_pointer(winstate->buffer, 0);
        if (((frameOptions & FRAMEOPTION_END_CURRENT_ROW) &&
             node->ordNumCols != 0) ||
            (frameOptions & FRAMEOPTION_END_OFFSET))
            winstate->frametail_ptr =
                tuplestore_alloc_read_pointer(winstate->buffer, 0);
    }
 
    /*
     * If we have an exclusion clause that requires knowing the boundaries of
     * the current row's peer group, we create a read pointer to track the
     * tail position of the peer group (i.e., first row of the next peer
     * group).  The head position does not require its own pointer because we
     * maintain that as a side effect of advancing the current row.
     */
    winstate->grouptail_ptr = -1;
 
    if ((frameOptions & (FRAMEOPTION_EXCLUDE_GROUP |
                         FRAMEOPTION_EXCLUDE_TIES)) &&
        node->ordNumCols != 0)
    {
        winstate->grouptail_ptr =
            tuplestore_alloc_read_pointer(winstate->buffer, 0);
    }
}

References WindowAggState::agg_winobj, Assert(), WindowAggState::buffer, WindowAggState::current_ptr, EXEC_FLAG_BACKWARD, WindowAggState::framehead_ptr, FRAMEOPTION_END_CURRENT_ROW, FRAMEOPTION_END_OFFSET, FRAMEOPTION_EXCLUDE_GROUP, FRAMEOPTION_EXCLUDE_TIES, FRAMEOPTION_EXCLUSION, FRAMEOPTION_GROUPS, FRAMEOPTION_RANGE, FRAMEOPTION_START_CURRENT_ROW, FRAMEOPTION_START_OFFSET, FRAMEOPTION_START_UNBOUNDED_PRECEDING, WindowAggState::frameOptions, WindowAggState::frametail_ptr, WindowAggState::grouptail_ptr, i, WindowObjectData::markptr, WindowAggState::numaggs, WindowAggState::numfuncs, WindowAgg::ordNumCols, WindowAggState::perfunc, WindowStatePerFuncData::plain_agg, PlanState::plan, ScanState::ps, WindowObjectData::readptr, WindowAggState::ss, tuplestore_alloc_read_pointer(), tuplestore_begin_heap(), tuplestore_set_eflags(), WindowStatePerFuncData::winobj, and work_mem.

Referenced by begin_partition().

◆ release_partition()

static void release_partition ( WindowAggState * winstate )

static

Definition at line 1376 of file nodeWindowAgg.c.

{
    int         i;
 
    for (i = 0; i < winstate->numfuncs; i++)
    {
        WindowStatePerFunc perfuncstate = &(winstate->perfunc[i]);
 
        /* Release any partition-local state of this window function */
        if (perfuncstate->winobj)
            perfuncstate->winobj->localmem = NULL;
    }
 
    /*
     * Release all partition-local memory (in particular, any partition-local
     * state that we might have trashed our pointers to in the above loop, and
     * any aggregate temp data).  We don't rely on retail pfree because some
     * aggregates might have allocated data we don't have direct pointers to.
     */
    MemoryContextReset(winstate->partcontext);
    MemoryContextReset(winstate->aggcontext);
    for (i = 0; i < winstate->numaggs; i++)
    {
        if (winstate->peragg[i].aggcontext != winstate->aggcontext)
            MemoryContextReset(winstate->peragg[i].aggcontext);
    }
 
    if (winstate->buffer)
        tuplestore_clear(winstate->buffer);
    winstate->partition_spooled = false;
    winstate->next_partition = true;
}

References WindowStatePerAggData::aggcontext, WindowAggState::aggcontext, WindowAggState::buffer, i, WindowObjectData::localmem, MemoryContextReset(), WindowAggState::next_partition, WindowAggState::numaggs, WindowAggState::numfuncs, WindowAggState::partcontext, WindowAggState::partition_spooled, WindowAggState::peragg, WindowAggState::perfunc, tuplestore_clear(), and WindowStatePerFuncData::winobj.

Referenced by ExecEndWindowAgg(), ExecReScanWindowAgg(), and ExecWindowAgg().

◆ row_is_in_frame()

static int row_is_in_frame	(	WindowAggState *	winstate,
		int64	pos,
		TupleTableSlot *	slot
	)

static

Definition at line 1426 of file nodeWindowAgg.c.

{
    int         frameOptions = winstate->frameOptions;
 
    Assert(pos >= 0);           /* else caller error */
 
    /*
     * First, check frame starting conditions.  We might as well delegate this
     * to update_frameheadpos always; it doesn't add any notable cost.
     */
    update_frameheadpos(winstate);
    if (pos < winstate->frameheadpos)
        return 0;
 
    /*
     * Okay so far, now check frame ending conditions.  Here, we avoid calling
     * update_frametailpos in simple cases, so as not to spool tuples further
     * ahead than necessary.
     */
    if (frameOptions & FRAMEOPTION_END_CURRENT_ROW)
    {
        if (frameOptions & FRAMEOPTION_ROWS)
        {
            /* rows after current row are out of frame */
            if (pos > winstate->currentpos)
                return -1;
        }
        else if (frameOptions & (FRAMEOPTION_RANGE | FRAMEOPTION_GROUPS))
        {
            /* following row that is not peer is out of frame */
            if (pos > winstate->currentpos &&
                !are_peers(winstate, slot, winstate->ss.ss_ScanTupleSlot))
                return -1;
        }
        else
            Assert(false);
    }
    else if (frameOptions & FRAMEOPTION_END_OFFSET)
    {
        if (frameOptions & FRAMEOPTION_ROWS)
        {
            int64       offset = DatumGetInt64(winstate->endOffsetValue);
 
            /* rows after current row + offset are out of frame */
            if (frameOptions & FRAMEOPTION_END_OFFSET_PRECEDING)
                offset = -offset;
 
            if (pos > winstate->currentpos + offset)
                return -1;
        }
        else if (frameOptions & (FRAMEOPTION_RANGE | FRAMEOPTION_GROUPS))
        {
            /* hard cases, so delegate to update_frametailpos */
            update_frametailpos(winstate);
            if (pos >= winstate->frametailpos)
                return -1;
        }
        else
            Assert(false);
    }
 
    /* Check exclusion clause */
    if (frameOptions & FRAMEOPTION_EXCLUDE_CURRENT_ROW)
    {
        if (pos == winstate->currentpos)
            return 0;
    }
    else if ((frameOptions & FRAMEOPTION_EXCLUDE_GROUP) ||
             ((frameOptions & FRAMEOPTION_EXCLUDE_TIES) &&
              pos != winstate->currentpos))
    {
        WindowAgg  *node = (WindowAgg *) winstate->ss.ps.plan;
 
        /* If no ORDER BY, all rows are peers with each other */
        if (node->ordNumCols == 0)
            return 0;
        /* Otherwise, check the group boundaries */
        if (pos >= winstate->groupheadpos)
        {
            update_grouptailpos(winstate);
            if (pos < winstate->grouptailpos)
                return 0;
        }
    }
 
    /* If we get here, it's in frame */
    return 1;
}

References are_peers(), Assert(), WindowAggState::currentpos, DatumGetInt64(), WindowAggState::endOffsetValue, FRAMEOPTION_END_CURRENT_ROW, FRAMEOPTION_END_OFFSET, FRAMEOPTION_END_OFFSET_PRECEDING, FRAMEOPTION_EXCLUDE_CURRENT_ROW, FRAMEOPTION_EXCLUDE_GROUP, FRAMEOPTION_EXCLUDE_TIES, FRAMEOPTION_GROUPS, FRAMEOPTION_RANGE, FRAMEOPTION_ROWS, WindowAggState::frameOptions, WindowAggState::frametailpos, WindowAggState::groupheadpos, if(), WindowAgg::ordNumCols, PlanState::plan, ScanState::ps, WindowAggState::ss, ScanState::ss_ScanTupleSlot, update_frameheadpos(), update_frametailpos(), and update_grouptailpos().

Referenced by eval_windowaggregates(), and WinGetFuncArgInFrame().

◆ spool_tuples()

static void spool_tuples	(	WindowAggState *	winstate,
		int64	pos
	)

static

Definition at line 1282 of file nodeWindowAgg.c.

{
    WindowAgg  *node = (WindowAgg *) winstate->ss.ps.plan;
    PlanState  *outerPlan;
    TupleTableSlot *outerslot;
    MemoryContext oldcontext;
 
    if (!winstate->buffer)
        return;                 /* just a safety check */
    if (winstate->partition_spooled)
        return;                 /* whole partition done already */
 
    /*
     * When in pass-through mode we can just exhaust all tuples in the current
     * partition.  We don't need these tuples for any further window function
     * evaluation, however, we do need to keep them around if we're not the
     * top-level window as another WindowAgg node above must see these.
     */
    if (winstate->status != WINDOWAGG_RUN)
    {
        Assert(winstate->status == WINDOWAGG_PASSTHROUGH ||
               winstate->status == WINDOWAGG_PASSTHROUGH_STRICT);
 
        pos = -1;
    }
 
    /*
     * If the tuplestore has spilled to disk, alternate reading and writing
     * becomes quite expensive due to frequent buffer flushes.  It's cheaper
     * to force the entire partition to get spooled in one go.
     *
     * XXX this is a horrid kluge --- it'd be better to fix the performance
     * problem inside tuplestore.  FIXME
     */
    else if (!tuplestore_in_memory(winstate->buffer))
        pos = -1;
 
    outerPlan = outerPlanState(winstate);
 
    /* Must be in query context to call outerplan */
    oldcontext = MemoryContextSwitchTo(winstate->ss.ps.ps_ExprContext->ecxt_per_query_memory);
 
    while (winstate->spooled_rows <= pos || pos == -1)
    {
        outerslot = ExecProcNode(outerPlan);
        if (TupIsNull(outerslot))
        {
            /* reached the end of the last partition */
            winstate->partition_spooled = true;
            winstate->more_partitions = false;
            break;
        }
 
        if (node->partNumCols > 0)
        {
            ExprContext *econtext = winstate->tmpcontext;
 
            econtext->ecxt_innertuple = winstate->first_part_slot;
            econtext->ecxt_outertuple = outerslot;
 
            /* Check if this tuple still belongs to the current partition */
            if (!ExecQualAndReset(winstate->partEqfunction, econtext))
            {
                /*
                 * end of partition; copy the tuple for the next cycle.
                 */
                ExecCopySlot(winstate->first_part_slot, outerslot);
                winstate->partition_spooled = true;
                winstate->more_partitions = true;
                break;
            }
        }
 
        /*
         * Remember the tuple unless we're the top-level window and we're in
         * pass-through mode.
         */
        if (winstate->status != WINDOWAGG_PASSTHROUGH_STRICT)
        {
            /* Still in partition, so save it into the tuplestore */
            tuplestore_puttupleslot(winstate->buffer, outerslot);
            winstate->spooled_rows++;
        }
    }
 
    MemoryContextSwitchTo(oldcontext);
}

References Assert(), WindowAggState::buffer, ExprContext::ecxt_innertuple, ExprContext::ecxt_outertuple, ExprContext::ecxt_per_query_memory, ExecCopySlot(), ExecProcNode(), ExecQualAndReset(), WindowAggState::first_part_slot, if(), MemoryContextSwitchTo(), WindowAggState::more_partitions, outerPlan, outerPlanState, WindowAggState::partEqfunction, WindowAggState::partition_spooled, WindowAgg::partNumCols, PlanState::plan, ScanState::ps, PlanState::ps_ExprContext, WindowAggState::spooled_rows, WindowAggState::ss, WindowAggState::status, WindowAggState::tmpcontext, TupIsNull, tuplestore_in_memory(), tuplestore_puttupleslot(), WINDOWAGG_PASSTHROUGH, WINDOWAGG_PASSTHROUGH_STRICT, and WINDOWAGG_RUN.

Referenced by ExecWindowAgg(), update_frameheadpos(), update_frametailpos(), update_grouptailpos(), window_gettupleslot(), WinGetFuncArgInPartition(), and WinGetPartitionRowCount().

◆ update_frameheadpos()

static void update_frameheadpos ( WindowAggState * winstate )

static

Definition at line 1526 of file nodeWindowAgg.c.

{
    WindowAgg  *node = (WindowAgg *) winstate->ss.ps.plan;
    int         frameOptions = winstate->frameOptions;
    MemoryContext oldcontext;
 
    if (winstate->framehead_valid)
        return;                 /* already known for current row */
 
    /* We may be called in a short-lived context */
    oldcontext = MemoryContextSwitchTo(winstate->ss.ps.ps_ExprContext->ecxt_per_query_memory);
 
    if (frameOptions & FRAMEOPTION_START_UNBOUNDED_PRECEDING)
    {
        /* In UNBOUNDED PRECEDING mode, frame head is always row 0 */
        winstate->frameheadpos = 0;
        winstate->framehead_valid = true;
    }
    else if (frameOptions & FRAMEOPTION_START_CURRENT_ROW)
    {
        if (frameOptions & FRAMEOPTION_ROWS)
        {
            /* In ROWS mode, frame head is the same as current */
            winstate->frameheadpos = winstate->currentpos;
            winstate->framehead_valid = true;
        }
        else if (frameOptions & (FRAMEOPTION_RANGE | FRAMEOPTION_GROUPS))
        {
            /* If no ORDER BY, all rows are peers with each other */
            if (node->ordNumCols == 0)
            {
                winstate->frameheadpos = 0;
                winstate->framehead_valid = true;
                MemoryContextSwitchTo(oldcontext);
                return;
            }
 
            /*
             * In RANGE or GROUPS START_CURRENT_ROW mode, frame head is the
             * first row that is a peer of current row.  We keep a copy of the
             * last-known frame head row in framehead_slot, and advance as
             * necessary.  Note that if we reach end of partition, we will
             * leave frameheadpos = end+1 and framehead_slot empty.
             */
            tuplestore_select_read_pointer(winstate->buffer,
                                           winstate->framehead_ptr);
            if (winstate->frameheadpos == 0 &&
                TupIsNull(winstate->framehead_slot))
            {
                /* fetch first row into framehead_slot, if we didn't already */
                if (!tuplestore_gettupleslot(winstate->buffer, true, true,
                                             winstate->framehead_slot))
                    elog(ERROR, "unexpected end of tuplestore");
            }
 
            while (!TupIsNull(winstate->framehead_slot))
            {
                if (are_peers(winstate, winstate->framehead_slot,
                              winstate->ss.ss_ScanTupleSlot))
                    break;      /* this row is the correct frame head */
                /* Note we advance frameheadpos even if the fetch fails */
                winstate->frameheadpos++;
                spool_tuples(winstate, winstate->frameheadpos);
                if (!tuplestore_gettupleslot(winstate->buffer, true, true,
                                             winstate->framehead_slot))
                    break;      /* end of partition */
            }
            winstate->framehead_valid = true;
        }
        else
            Assert(false);
    }
    else if (frameOptions & FRAMEOPTION_START_OFFSET)
    {
        if (frameOptions & FRAMEOPTION_ROWS)
        {
            /* In ROWS mode, bound is physically n before/after current */
            int64       offset = DatumGetInt64(winstate->startOffsetValue);
 
            if (frameOptions & FRAMEOPTION_START_OFFSET_PRECEDING)
                offset = -offset;
 
            winstate->frameheadpos = winstate->currentpos + offset;
            /* frame head can't go before first row */
            if (winstate->frameheadpos < 0)
                winstate->frameheadpos = 0;
            else if (winstate->frameheadpos > winstate->currentpos + 1)
            {
                /* make sure frameheadpos is not past end of partition */
                spool_tuples(winstate, winstate->frameheadpos - 1);
                if (winstate->frameheadpos > winstate->spooled_rows)
                    winstate->frameheadpos = winstate->spooled_rows;
            }
            winstate->framehead_valid = true;
        }
        else if (frameOptions & FRAMEOPTION_RANGE)
        {
            /*
             * In RANGE START_OFFSET mode, frame head is the first row that
             * satisfies the in_range constraint relative to the current row.
             * We keep a copy of the last-known frame head row in
             * framehead_slot, and advance as necessary.  Note that if we
             * reach end of partition, we will leave frameheadpos = end+1 and
             * framehead_slot empty.
             */
            int         sortCol = node->ordColIdx[0];
            bool        sub,
                        less;
 
            /* We must have an ordering column */
            Assert(node->ordNumCols == 1);
 
            /* Precompute flags for in_range checks */
            if (frameOptions & FRAMEOPTION_START_OFFSET_PRECEDING)
                sub = true;     /* subtract startOffset from current row */
            else
                sub = false;    /* add it */
            less = false;       /* normally, we want frame head >= sum */
            /* If sort order is descending, flip both flags */
            if (!winstate->inRangeAsc)
            {
                sub = !sub;
                less = true;
            }
 
            tuplestore_select_read_pointer(winstate->buffer,
                                           winstate->framehead_ptr);
            if (winstate->frameheadpos == 0 &&
                TupIsNull(winstate->framehead_slot))
            {
                /* fetch first row into framehead_slot, if we didn't already */
                if (!tuplestore_gettupleslot(winstate->buffer, true, true,
                                             winstate->framehead_slot))
                    elog(ERROR, "unexpected end of tuplestore");
            }
 
            while (!TupIsNull(winstate->framehead_slot))
            {
                Datum       headval,
                            currval;
                bool        headisnull,
                            currisnull;
 
                headval = slot_getattr(winstate->framehead_slot, sortCol,
                                       &headisnull);
                currval = slot_getattr(winstate->ss.ss_ScanTupleSlot, sortCol,
                                       &currisnull);
                if (headisnull || currisnull)
                {
                    /* order of the rows depends only on nulls_first */
                    if (winstate->inRangeNullsFirst)
                    {
                        /* advance head if head is null and curr is not */
                        if (!headisnull || currisnull)
                            break;
                    }
                    else
                    {
                        /* advance head if head is not null and curr is null */
                        if (headisnull || !currisnull)
                            break;
                    }
                }
                else
                {
                    if (DatumGetBool(FunctionCall5Coll(&winstate->startInRangeFunc,
                                                       winstate->inRangeColl,
                                                       headval,
                                                       currval,
                                                       winstate->startOffsetValue,
                                                       BoolGetDatum(sub),
                                                       BoolGetDatum(less))))
                        break;  /* this row is the correct frame head */
                }
                /* Note we advance frameheadpos even if the fetch fails */
                winstate->frameheadpos++;
                spool_tuples(winstate, winstate->frameheadpos);
                if (!tuplestore_gettupleslot(winstate->buffer, true, true,
                                             winstate->framehead_slot))
                    break;      /* end of partition */
            }
            winstate->framehead_valid = true;
        }
        else if (frameOptions & FRAMEOPTION_GROUPS)
        {
            /*
             * In GROUPS START_OFFSET mode, frame head is the first row of the
             * first peer group whose number satisfies the offset constraint.
             * We keep a copy of the last-known frame head row in
             * framehead_slot, and advance as necessary.  Note that if we
             * reach end of partition, we will leave frameheadpos = end+1 and
             * framehead_slot empty.
             */
            int64       offset = DatumGetInt64(winstate->startOffsetValue);
            int64       minheadgroup;
 
            if (frameOptions & FRAMEOPTION_START_OFFSET_PRECEDING)
                minheadgroup = winstate->currentgroup - offset;
            else
                minheadgroup = winstate->currentgroup + offset;
 
            tuplestore_select_read_pointer(winstate->buffer,
                                           winstate->framehead_ptr);
            if (winstate->frameheadpos == 0 &&
                TupIsNull(winstate->framehead_slot))
            {
                /* fetch first row into framehead_slot, if we didn't already */
                if (!tuplestore_gettupleslot(winstate->buffer, true, true,
                                             winstate->framehead_slot))
                    elog(ERROR, "unexpected end of tuplestore");
            }
 
            while (!TupIsNull(winstate->framehead_slot))
            {
                if (winstate->frameheadgroup >= minheadgroup)
                    break;      /* this row is the correct frame head */
                ExecCopySlot(winstate->temp_slot_2, winstate->framehead_slot);
                /* Note we advance frameheadpos even if the fetch fails */
                winstate->frameheadpos++;
                spool_tuples(winstate, winstate->frameheadpos);
                if (!tuplestore_gettupleslot(winstate->buffer, true, true,
                                             winstate->framehead_slot))
                    break;      /* end of partition */
                if (!are_peers(winstate, winstate->temp_slot_2,
                               winstate->framehead_slot))
                    winstate->frameheadgroup++;
            }
            ExecClearTuple(winstate->temp_slot_2);
            winstate->framehead_valid = true;
        }
        else
            Assert(false);
    }
    else
        Assert(false);
 
    MemoryContextSwitchTo(oldcontext);
}

References are_peers(), Assert(), BoolGetDatum(), WindowAggState::buffer, WindowAggState::currentgroup, WindowAggState::currentpos, DatumGetBool(), DatumGetInt64(), ExprContext::ecxt_per_query_memory, elog, ERROR, ExecClearTuple(), ExecCopySlot(), WindowAggState::framehead_ptr, WindowAggState::framehead_slot, WindowAggState::framehead_valid, WindowAggState::frameheadgroup, WindowAggState::frameheadpos, FRAMEOPTION_GROUPS, FRAMEOPTION_RANGE, FRAMEOPTION_ROWS, FRAMEOPTION_START_CURRENT_ROW, FRAMEOPTION_START_OFFSET, FRAMEOPTION_START_OFFSET_PRECEDING, FRAMEOPTION_START_UNBOUNDED_PRECEDING, WindowAggState::frameOptions, FunctionCall5Coll(), if(), WindowAggState::inRangeAsc, WindowAggState::inRangeColl, WindowAggState::inRangeNullsFirst, MemoryContextSwitchTo(), WindowAgg::ordNumCols, PlanState::plan, ScanState::ps, PlanState::ps_ExprContext, slot_getattr(), spool_tuples(), WindowAggState::spooled_rows, WindowAggState::ss, ScanState::ss_ScanTupleSlot, WindowAggState::startInRangeFunc, WindowAggState::startOffsetValue, WindowAggState::temp_slot_2, TupIsNull, tuplestore_gettupleslot(), and tuplestore_select_read_pointer().

Referenced by eval_windowaggregates(), ExecWindowAgg(), row_is_in_frame(), and WinGetFuncArgInFrame().

◆ update_frametailpos()

static void update_frametailpos ( WindowAggState * winstate )

static

Definition at line 1776 of file nodeWindowAgg.c.

{
    WindowAgg  *node = (WindowAgg *) winstate->ss.ps.plan;
    int         frameOptions = winstate->frameOptions;
    MemoryContext oldcontext;
 
    if (winstate->frametail_valid)
        return;                 /* already known for current row */
 
    /* We may be called in a short-lived context */
    oldcontext = MemoryContextSwitchTo(winstate->ss.ps.ps_ExprContext->ecxt_per_query_memory);
 
    if (frameOptions & FRAMEOPTION_END_UNBOUNDED_FOLLOWING)
    {
        /* In UNBOUNDED FOLLOWING mode, all partition rows are in frame */
        spool_tuples(winstate, -1);
        winstate->frametailpos = winstate->spooled_rows;
        winstate->frametail_valid = true;
    }
    else if (frameOptions & FRAMEOPTION_END_CURRENT_ROW)
    {
        if (frameOptions & FRAMEOPTION_ROWS)
        {
            /* In ROWS mode, exactly the rows up to current are in frame */
            winstate->frametailpos = winstate->currentpos + 1;
            winstate->frametail_valid = true;
        }
        else if (frameOptions & (FRAMEOPTION_RANGE | FRAMEOPTION_GROUPS))
        {
            /* If no ORDER BY, all rows are peers with each other */
            if (node->ordNumCols == 0)
            {
                spool_tuples(winstate, -1);
                winstate->frametailpos = winstate->spooled_rows;
                winstate->frametail_valid = true;
                MemoryContextSwitchTo(oldcontext);
                return;
            }
 
            /*
             * In RANGE or GROUPS END_CURRENT_ROW mode, frame end is the last
             * row that is a peer of current row, frame tail is the row after
             * that (if any).  We keep a copy of the last-known frame tail row
             * in frametail_slot, and advance as necessary.  Note that if we
             * reach end of partition, we will leave frametailpos = end+1 and
             * frametail_slot empty.
             */
            tuplestore_select_read_pointer(winstate->buffer,
                                           winstate->frametail_ptr);
            if (winstate->frametailpos == 0 &&
                TupIsNull(winstate->frametail_slot))
            {
                /* fetch first row into frametail_slot, if we didn't already */
                if (!tuplestore_gettupleslot(winstate->buffer, true, true,
                                             winstate->frametail_slot))
                    elog(ERROR, "unexpected end of tuplestore");
            }
 
            while (!TupIsNull(winstate->frametail_slot))
            {
                if (winstate->frametailpos > winstate->currentpos &&
                    !are_peers(winstate, winstate->frametail_slot,
                               winstate->ss.ss_ScanTupleSlot))
                    break;      /* this row is the frame tail */
                /* Note we advance frametailpos even if the fetch fails */
                winstate->frametailpos++;
                spool_tuples(winstate, winstate->frametailpos);
                if (!tuplestore_gettupleslot(winstate->buffer, true, true,
                                             winstate->frametail_slot))
                    break;      /* end of partition */
            }
            winstate->frametail_valid = true;
        }
        else
            Assert(false);
    }
    else if (frameOptions & FRAMEOPTION_END_OFFSET)
    {
        if (frameOptions & FRAMEOPTION_ROWS)
        {
            /* In ROWS mode, bound is physically n before/after current */
            int64       offset = DatumGetInt64(winstate->endOffsetValue);
 
            if (frameOptions & FRAMEOPTION_END_OFFSET_PRECEDING)
                offset = -offset;
 
            winstate->frametailpos = winstate->currentpos + offset + 1;
            /* smallest allowable value of frametailpos is 0 */
            if (winstate->frametailpos < 0)
                winstate->frametailpos = 0;
            else if (winstate->frametailpos > winstate->currentpos + 1)
            {
                /* make sure frametailpos is not past end of partition */
                spool_tuples(winstate, winstate->frametailpos - 1);
                if (winstate->frametailpos > winstate->spooled_rows)
                    winstate->frametailpos = winstate->spooled_rows;
            }
            winstate->frametail_valid = true;
        }
        else if (frameOptions & FRAMEOPTION_RANGE)
        {
            /*
             * In RANGE END_OFFSET mode, frame end is the last row that
             * satisfies the in_range constraint relative to the current row,
             * frame tail is the row after that (if any).  We keep a copy of
             * the last-known frame tail row in frametail_slot, and advance as
             * necessary.  Note that if we reach end of partition, we will
             * leave frametailpos = end+1 and frametail_slot empty.
             */
            int         sortCol = node->ordColIdx[0];
            bool        sub,
                        less;
 
            /* We must have an ordering column */
            Assert(node->ordNumCols == 1);
 
            /* Precompute flags for in_range checks */
            if (frameOptions & FRAMEOPTION_END_OFFSET_PRECEDING)
                sub = true;     /* subtract endOffset from current row */
            else
                sub = false;    /* add it */
            less = true;        /* normally, we want frame tail <= sum */
            /* If sort order is descending, flip both flags */
            if (!winstate->inRangeAsc)
            {
                sub = !sub;
                less = false;
            }
 
            tuplestore_select_read_pointer(winstate->buffer,
                                           winstate->frametail_ptr);
            if (winstate->frametailpos == 0 &&
                TupIsNull(winstate->frametail_slot))
            {
                /* fetch first row into frametail_slot, if we didn't already */
                if (!tuplestore_gettupleslot(winstate->buffer, true, true,
                                             winstate->frametail_slot))
                    elog(ERROR, "unexpected end of tuplestore");
            }
 
            while (!TupIsNull(winstate->frametail_slot))
            {
                Datum       tailval,
                            currval;
                bool        tailisnull,
                            currisnull;
 
                tailval = slot_getattr(winstate->frametail_slot, sortCol,
                                       &tailisnull);
                currval = slot_getattr(winstate->ss.ss_ScanTupleSlot, sortCol,
                                       &currisnull);
                if (tailisnull || currisnull)
                {
                    /* order of the rows depends only on nulls_first */
                    if (winstate->inRangeNullsFirst)
                    {
                        /* advance tail if tail is null or curr is not */
                        if (!tailisnull)
                            break;
                    }
                    else
                    {
                        /* advance tail if tail is not null or curr is null */
                        if (!currisnull)
                            break;
                    }
                }
                else
                {
                    if (!DatumGetBool(FunctionCall5Coll(&winstate->endInRangeFunc,
                                                        winstate->inRangeColl,
                                                        tailval,
                                                        currval,
                                                        winstate->endOffsetValue,
                                                        BoolGetDatum(sub),
                                                        BoolGetDatum(less))))
                        break;  /* this row is the correct frame tail */
                }
                /* Note we advance frametailpos even if the fetch fails */
                winstate->frametailpos++;
                spool_tuples(winstate, winstate->frametailpos);
                if (!tuplestore_gettupleslot(winstate->buffer, true, true,
                                             winstate->frametail_slot))
                    break;      /* end of partition */
            }
            winstate->frametail_valid = true;
        }
        else if (frameOptions & FRAMEOPTION_GROUPS)
        {
            /*
             * In GROUPS END_OFFSET mode, frame end is the last row of the
             * last peer group whose number satisfies the offset constraint,
             * and frame tail is the row after that (if any).  We keep a copy
             * of the last-known frame tail row in frametail_slot, and advance
             * as necessary.  Note that if we reach end of partition, we will
             * leave frametailpos = end+1 and frametail_slot empty.
             */
            int64       offset = DatumGetInt64(winstate->endOffsetValue);
            int64       maxtailgroup;
 
            if (frameOptions & FRAMEOPTION_END_OFFSET_PRECEDING)
                maxtailgroup = winstate->currentgroup - offset;
            else
                maxtailgroup = winstate->currentgroup + offset;
 
            tuplestore_select_read_pointer(winstate->buffer,
                                           winstate->frametail_ptr);
            if (winstate->frametailpos == 0 &&
                TupIsNull(winstate->frametail_slot))
            {
                /* fetch first row into frametail_slot, if we didn't already */
                if (!tuplestore_gettupleslot(winstate->buffer, true, true,
                                             winstate->frametail_slot))
                    elog(ERROR, "unexpected end of tuplestore");
            }
 
            while (!TupIsNull(winstate->frametail_slot))
            {
                if (winstate->frametailgroup > maxtailgroup)
                    break;      /* this row is the correct frame tail */
                ExecCopySlot(winstate->temp_slot_2, winstate->frametail_slot);
                /* Note we advance frametailpos even if the fetch fails */
                winstate->frametailpos++;
                spool_tuples(winstate, winstate->frametailpos);
                if (!tuplestore_gettupleslot(winstate->buffer, true, true,
                                             winstate->frametail_slot))
                    break;      /* end of partition */
                if (!are_peers(winstate, winstate->temp_slot_2,
                               winstate->frametail_slot))
                    winstate->frametailgroup++;
            }
            ExecClearTuple(winstate->temp_slot_2);
            winstate->frametail_valid = true;
        }
        else
            Assert(false);
    }
    else
        Assert(false);
 
    MemoryContextSwitchTo(oldcontext);
}

References are_peers(), Assert(), BoolGetDatum(), WindowAggState::buffer, WindowAggState::currentgroup, WindowAggState::currentpos, DatumGetBool(), DatumGetInt64(), ExprContext::ecxt_per_query_memory, elog, WindowAggState::endInRangeFunc, WindowAggState::endOffsetValue, ERROR, ExecClearTuple(), ExecCopySlot(), FRAMEOPTION_END_CURRENT_ROW, FRAMEOPTION_END_OFFSET, FRAMEOPTION_END_OFFSET_PRECEDING, FRAMEOPTION_END_UNBOUNDED_FOLLOWING, FRAMEOPTION_GROUPS, FRAMEOPTION_RANGE, FRAMEOPTION_ROWS, WindowAggState::frameOptions, WindowAggState::frametail_ptr, WindowAggState::frametail_slot, WindowAggState::frametail_valid, WindowAggState::frametailgroup, WindowAggState::frametailpos, FunctionCall5Coll(), if(), WindowAggState::inRangeAsc, WindowAggState::inRangeColl, WindowAggState::inRangeNullsFirst, MemoryContextSwitchTo(), WindowAgg::ordNumCols, PlanState::plan, ScanState::ps, PlanState::ps_ExprContext, slot_getattr(), spool_tuples(), WindowAggState::spooled_rows, WindowAggState::ss, ScanState::ss_ScanTupleSlot, WindowAggState::temp_slot_2, TupIsNull, tuplestore_gettupleslot(), and tuplestore_select_read_pointer().

Referenced by ExecWindowAgg(), row_is_in_frame(), and WinGetFuncArgInFrame().

◆ update_grouptailpos()

static void update_grouptailpos ( WindowAggState * winstate )

static

Definition at line 2026 of file nodeWindowAgg.c.

{
    WindowAgg  *node = (WindowAgg *) winstate->ss.ps.plan;
    MemoryContext oldcontext;
 
    if (winstate->grouptail_valid)
        return;                 /* already known for current row */
 
    /* We may be called in a short-lived context */
    oldcontext = MemoryContextSwitchTo(winstate->ss.ps.ps_ExprContext->ecxt_per_query_memory);
 
    /* If no ORDER BY, all rows are peers with each other */
    if (node->ordNumCols == 0)
    {
        spool_tuples(winstate, -1);
        winstate->grouptailpos = winstate->spooled_rows;
        winstate->grouptail_valid = true;
        MemoryContextSwitchTo(oldcontext);
        return;
    }
 
    /*
     * Because grouptail_valid is reset only when current row advances into a
     * new peer group, we always reach here knowing that grouptailpos needs to
     * be advanced by at least one row.  Hence, unlike the otherwise similar
     * case for frame tail tracking, we do not need persistent storage of the
     * group tail row.
     */
    Assert(winstate->grouptailpos <= winstate->currentpos);
    tuplestore_select_read_pointer(winstate->buffer,
                                   winstate->grouptail_ptr);
    for (;;)
    {
        /* Note we advance grouptailpos even if the fetch fails */
        winstate->grouptailpos++;
        spool_tuples(winstate, winstate->grouptailpos);
        if (!tuplestore_gettupleslot(winstate->buffer, true, true,
                                     winstate->temp_slot_2))
            break;              /* end of partition */
        if (winstate->grouptailpos > winstate->currentpos &&
            !are_peers(winstate, winstate->temp_slot_2,
                       winstate->ss.ss_ScanTupleSlot))
            break;              /* this row is the group tail */
    }
    ExecClearTuple(winstate->temp_slot_2);
    winstate->grouptail_valid = true;
 
    MemoryContextSwitchTo(oldcontext);
}

References are_peers(), Assert(), WindowAggState::buffer, WindowAggState::currentpos, ExprContext::ecxt_per_query_memory, ExecClearTuple(), WindowAggState::grouptail_ptr, WindowAggState::grouptail_valid, WindowAggState::grouptailpos, if(), MemoryContextSwitchTo(), WindowAgg::ordNumCols, PlanState::plan, ScanState::ps, PlanState::ps_ExprContext, spool_tuples(), WindowAggState::spooled_rows, WindowAggState::ss, ScanState::ss_ScanTupleSlot, WindowAggState::temp_slot_2, tuplestore_gettupleslot(), and tuplestore_select_read_pointer().

Referenced by ExecWindowAgg(), row_is_in_frame(), and WinGetFuncArgInFrame().

◆ window_gettupleslot()

static bool window_gettupleslot	(	WindowObject	winobj,
		int64	pos,
		TupleTableSlot *	slot
	)

static

Definition at line 3132 of file nodeWindowAgg.c.

{
    WindowAggState *winstate = winobj->winstate;
    MemoryContext oldcontext;
 
    /* often called repeatedly in a row */
    CHECK_FOR_INTERRUPTS();
 
    /* Don't allow passing -1 to spool_tuples here */
    if (pos < 0)
        return false;
 
    /* If necessary, fetch the tuple into the spool */
    spool_tuples(winstate, pos);
 
    if (pos >= winstate->spooled_rows)
        return false;
 
    if (pos < winobj->markpos)
        elog(ERROR, "cannot fetch row before WindowObject's mark position");
 
    oldcontext = MemoryContextSwitchTo(winstate->ss.ps.ps_ExprContext->ecxt_per_query_memory);
 
    tuplestore_select_read_pointer(winstate->buffer, winobj->readptr);
 
    /*
     * Advance or rewind until we are within one tuple of the one we want.
     */
    if (winobj->seekpos < pos - 1)
    {
        if (!tuplestore_skiptuples(winstate->buffer,
                                   pos - 1 - winobj->seekpos,
                                   true))
            elog(ERROR, "unexpected end of tuplestore");
        winobj->seekpos = pos - 1;
    }
    else if (winobj->seekpos > pos + 1)
    {
        if (!tuplestore_skiptuples(winstate->buffer,
                                   winobj->seekpos - (pos + 1),
                                   false))
            elog(ERROR, "unexpected end of tuplestore");
        winobj->seekpos = pos + 1;
    }
    else if (winobj->seekpos == pos)
    {
        /*
         * There's no API to refetch the tuple at the current position.  We
         * have to move one tuple forward, and then one backward.  (We don't
         * do it the other way because we might try to fetch the row before
         * our mark, which isn't allowed.)  XXX this case could stand to be
         * optimized.
         */
        tuplestore_advance(winstate->buffer, true);
        winobj->seekpos++;
    }
 
    /*
     * Now we should be on the tuple immediately before or after the one we
     * want, so just fetch forwards or backwards as appropriate.
     *
     * Notice that we tell tuplestore_gettupleslot to make a physical copy of
     * the fetched tuple.  This ensures that the slot's contents remain valid
     * through manipulations of the tuplestore, which some callers depend on.
     */
    if (winobj->seekpos > pos)
    {
        if (!tuplestore_gettupleslot(winstate->buffer, false, true, slot))
            elog(ERROR, "unexpected end of tuplestore");
        winobj->seekpos--;
    }
    else
    {
        if (!tuplestore_gettupleslot(winstate->buffer, true, true, slot))
            elog(ERROR, "unexpected end of tuplestore");
        winobj->seekpos++;
    }
 
    Assert(winobj->seekpos == pos);
 
    MemoryContextSwitchTo(oldcontext);
 
    return true;
}

References Assert(), WindowAggState::buffer, CHECK_FOR_INTERRUPTS, ExprContext::ecxt_per_query_memory, elog, ERROR, MemoryContextSwitchTo(), ScanState::ps, PlanState::ps_ExprContext, WindowObjectData::readptr, WindowObjectData::seekpos, spool_tuples(), WindowAggState::spooled_rows, WindowAggState::ss, tuplestore_advance(), tuplestore_gettupleslot(), tuplestore_select_read_pointer(), tuplestore_skiptuples(), and WindowObjectData::winstate.

Referenced by eval_windowaggregates(), WinGetFuncArgInFrame(), WinGetFuncArgInPartition(), and WinRowsArePeers().

◆ WinGetCurrentPosition()

int64 WinGetCurrentPosition ( WindowObject winobj )

Definition at line 3251 of file nodeWindowAgg.c.

{
    Assert(WindowObjectIsValid(winobj));
    return winobj->winstate->currentpos;
}

References Assert(), WindowAggState::currentpos, WindowObjectIsValid, and WindowObjectData::winstate.

Referenced by rank_up(), window_cume_dist(), window_percent_rank(), window_rank(), and window_row_number().

◆ WinGetFuncArgCurrent()

Datum WinGetFuncArgCurrent	(	WindowObject	winobj,
		int	argno,
		bool *	isnull
	)

Definition at line 3659 of file nodeWindowAgg.c.

{
    WindowAggState *winstate;
    ExprContext *econtext;
 
    Assert(WindowObjectIsValid(winobj));
    winstate = winobj->winstate;
 
    econtext = winstate->ss.ps.ps_ExprContext;
 
    econtext->ecxt_outertuple = winstate->ss.ss_ScanTupleSlot;
    return ExecEvalExpr((ExprState *) list_nth(winobj->argstates, argno),
                        econtext, isnull);
}

References WindowObjectData::argstates, Assert(), ExprContext::ecxt_outertuple, ExecEvalExpr(), list_nth(), ScanState::ps, PlanState::ps_ExprContext, WindowAggState::ss, ScanState::ss_ScanTupleSlot, WindowObjectIsValid, and WindowObjectData::winstate.

Referenced by leadlag_common(), window_nth_value(), and window_ntile().

◆ WinGetFuncArgInFrame()

Datum WinGetFuncArgInFrame	(	WindowObject	winobj,
		int	argno,
		int	relpos,
		int	seektype,
		bool	set_mark,
		bool *	isnull,
		bool *	isout
	)

Definition at line 3464 of file nodeWindowAgg.c.

{
    WindowAggState *winstate;
    ExprContext *econtext;
    TupleTableSlot *slot;
    int64       abs_pos;
    int64       mark_pos;
 
    Assert(WindowObjectIsValid(winobj));
    winstate = winobj->winstate;
    econtext = winstate->ss.ps.ps_ExprContext;
    slot = winstate->temp_slot_1;
 
    switch (seektype)
    {
        case WINDOW_SEEK_CURRENT:
            elog(ERROR, "WINDOW_SEEK_CURRENT is not supported for WinGetFuncArgInFrame");
            abs_pos = mark_pos = 0; /* keep compiler quiet */
            break;
        case WINDOW_SEEK_HEAD:
            /* rejecting relpos < 0 is easy and simplifies code below */
            if (relpos < 0)
                goto out_of_frame;
            update_frameheadpos(winstate);
            abs_pos = winstate->frameheadpos + relpos;
            mark_pos = abs_pos;
 
            /*
             * Account for exclusion option if one is active, but advance only
             * abs_pos not mark_pos.  This prevents changes of the current
             * row's peer group from resulting in trying to fetch a row before
             * some previous mark position.
             *
             * Note that in some corner cases such as current row being
             * outside frame, these calculations are theoretically too simple,
             * but it doesn't matter because we'll end up deciding the row is
             * out of frame.  We do not attempt to avoid fetching rows past
             * end of frame; that would happen in some cases anyway.
             */
            switch (winstate->frameOptions & FRAMEOPTION_EXCLUSION)
            {
                case 0:
                    /* no adjustment needed */
                    break;
                case FRAMEOPTION_EXCLUDE_CURRENT_ROW:
                    if (abs_pos >= winstate->currentpos &&
                        winstate->currentpos >= winstate->frameheadpos)
                        abs_pos++;
                    break;
                case FRAMEOPTION_EXCLUDE_GROUP:
                    update_grouptailpos(winstate);
                    if (abs_pos >= winstate->groupheadpos &&
                        winstate->grouptailpos > winstate->frameheadpos)
                    {
                        int64       overlapstart = Max(winstate->groupheadpos,
                                                       winstate->frameheadpos);
 
                        abs_pos += winstate->grouptailpos - overlapstart;
                    }
                    break;
                case FRAMEOPTION_EXCLUDE_TIES:
                    update_grouptailpos(winstate);
                    if (abs_pos >= winstate->groupheadpos &&
                        winstate->grouptailpos > winstate->frameheadpos)
                    {
                        int64       overlapstart = Max(winstate->groupheadpos,
                                                       winstate->frameheadpos);
 
                        if (abs_pos == overlapstart)
                            abs_pos = winstate->currentpos;
                        else
                            abs_pos += winstate->grouptailpos - overlapstart - 1;
                    }
                    break;
                default:
                    elog(ERROR, "unrecognized frame option state: 0x%x",
                         winstate->frameOptions);
                    break;
            }
            break;
        case WINDOW_SEEK_TAIL:
            /* rejecting relpos > 0 is easy and simplifies code below */
            if (relpos > 0)
                goto out_of_frame;
            update_frametailpos(winstate);
            abs_pos = winstate->frametailpos - 1 + relpos;
 
            /*
             * Account for exclusion option if one is active.  If there is no
             * exclusion, we can safely set the mark at the accessed row.  But
             * if there is, we can only mark the frame start, because we can't
             * be sure how far back in the frame the exclusion might cause us
             * to fetch in future.  Furthermore, we have to actually check
             * against frameheadpos here, since it's unsafe to try to fetch a
             * row before frame start if the mark might be there already.
             */
            switch (winstate->frameOptions & FRAMEOPTION_EXCLUSION)
            {
                case 0:
                    /* no adjustment needed */
                    mark_pos = abs_pos;
                    break;
                case FRAMEOPTION_EXCLUDE_CURRENT_ROW:
                    if (abs_pos <= winstate->currentpos &&
                        winstate->currentpos < winstate->frametailpos)
                        abs_pos--;
                    update_frameheadpos(winstate);
                    if (abs_pos < winstate->frameheadpos)
                        goto out_of_frame;
                    mark_pos = winstate->frameheadpos;
                    break;
                case FRAMEOPTION_EXCLUDE_GROUP:
                    update_grouptailpos(winstate);
                    if (abs_pos < winstate->grouptailpos &&
                        winstate->groupheadpos < winstate->frametailpos)
                    {
                        int64       overlapend = Min(winstate->grouptailpos,
                                                     winstate->frametailpos);
 
                        abs_pos -= overlapend - winstate->groupheadpos;
                    }
                    update_frameheadpos(winstate);
                    if (abs_pos < winstate->frameheadpos)
                        goto out_of_frame;
                    mark_pos = winstate->frameheadpos;
                    break;
                case FRAMEOPTION_EXCLUDE_TIES:
                    update_grouptailpos(winstate);
                    if (abs_pos < winstate->grouptailpos &&
                        winstate->groupheadpos < winstate->frametailpos)
                    {
                        int64       overlapend = Min(winstate->grouptailpos,
                                                     winstate->frametailpos);
 
                        if (abs_pos == overlapend - 1)
                            abs_pos = winstate->currentpos;
                        else
                            abs_pos -= overlapend - 1 - winstate->groupheadpos;
                    }
                    update_frameheadpos(winstate);
                    if (abs_pos < winstate->frameheadpos)
                        goto out_of_frame;
                    mark_pos = winstate->frameheadpos;
                    break;
                default:
                    elog(ERROR, "unrecognized frame option state: 0x%x",
                         winstate->frameOptions);
                    mark_pos = 0;   /* keep compiler quiet */
                    break;
            }
            break;
        default:
            elog(ERROR, "unrecognized window seek type: %d", seektype);
            abs_pos = mark_pos = 0; /* keep compiler quiet */
            break;
    }
 
    if (!window_gettupleslot(winobj, abs_pos, slot))
        goto out_of_frame;
 
    /* The code above does not detect all out-of-frame cases, so check */
    if (row_is_in_frame(winstate, abs_pos, slot) <= 0)
        goto out_of_frame;
 
    if (isout)
        *isout = false;
    if (set_mark)
        WinSetMarkPosition(winobj, mark_pos);
    econtext->ecxt_outertuple = slot;
    return ExecEvalExpr((ExprState *) list_nth(winobj->argstates, argno),
                        econtext, isnull);
 
out_of_frame:
    if (isout)
        *isout = true;
    *isnull = true;
    return (Datum) 0;
}

References WindowObjectData::argstates, Assert(), WindowAggState::currentpos, ExprContext::ecxt_outertuple, elog, ERROR, ExecEvalExpr(), WindowAggState::frameheadpos, FRAMEOPTION_EXCLUDE_CURRENT_ROW, FRAMEOPTION_EXCLUDE_GROUP, FRAMEOPTION_EXCLUDE_TIES, FRAMEOPTION_EXCLUSION, WindowAggState::frameOptions, WindowAggState::frametailpos, WindowAggState::groupheadpos, WindowAggState::grouptailpos, list_nth(), Max, Min, ScanState::ps, PlanState::ps_ExprContext, row_is_in_frame(), WindowAggState::ss, WindowAggState::temp_slot_1, update_frameheadpos(), update_frametailpos(), update_grouptailpos(), window_gettupleslot(), WINDOW_SEEK_CURRENT, WINDOW_SEEK_HEAD, WINDOW_SEEK_TAIL, WindowObjectIsValid, WinSetMarkPosition(), and WindowObjectData::winstate.

Referenced by window_first_value(), window_last_value(), and window_nth_value().

◆ WinGetFuncArgInPartition()

Datum WinGetFuncArgInPartition	(	WindowObject	winobj,
		int	argno,
		int	relpos,
		int	seektype,
		bool	set_mark,
		bool *	isnull,
		bool *	isout
	)

Definition at line 3376 of file nodeWindowAgg.c.

{
    WindowAggState *winstate;
    ExprContext *econtext;
    TupleTableSlot *slot;
    bool        gottuple;
    int64       abs_pos;
 
    Assert(WindowObjectIsValid(winobj));
    winstate = winobj->winstate;
    econtext = winstate->ss.ps.ps_ExprContext;
    slot = winstate->temp_slot_1;
 
    switch (seektype)
    {
        case WINDOW_SEEK_CURRENT:
            abs_pos = winstate->currentpos + relpos;
            break;
        case WINDOW_SEEK_HEAD:
            abs_pos = relpos;
            break;
        case WINDOW_SEEK_TAIL:
            spool_tuples(winstate, -1);
            abs_pos = winstate->spooled_rows - 1 + relpos;
            break;
        default:
            elog(ERROR, "unrecognized window seek type: %d", seektype);
            abs_pos = 0;        /* keep compiler quiet */
            break;
    }
 
    gottuple = window_gettupleslot(winobj, abs_pos, slot);
 
    if (!gottuple)
    {
        if (isout)
            *isout = true;
        *isnull = true;
        return (Datum) 0;
    }
    else
    {
        if (isout)
            *isout = false;
        if (set_mark)
            WinSetMarkPosition(winobj, abs_pos);
        econtext->ecxt_outertuple = slot;
        return ExecEvalExpr((ExprState *) list_nth(winobj->argstates, argno),
                            econtext, isnull);
    }
}

References WindowObjectData::argstates, Assert(), WindowAggState::currentpos, ExprContext::ecxt_outertuple, elog, ERROR, ExecEvalExpr(), list_nth(), ScanState::ps, PlanState::ps_ExprContext, spool_tuples(), WindowAggState::spooled_rows, WindowAggState::ss, WindowAggState::temp_slot_1, window_gettupleslot(), WINDOW_SEEK_CURRENT, WINDOW_SEEK_HEAD, WINDOW_SEEK_TAIL, WindowObjectIsValid, WinSetMarkPosition(), and WindowObjectData::winstate.

Referenced by leadlag_common().

◆ WinGetPartitionLocalMemory()

void * WinGetPartitionLocalMemory	(	WindowObject	winobj,
		Size	sz
	)

Definition at line 3236 of file nodeWindowAgg.c.

{
    Assert(WindowObjectIsValid(winobj));
    if (winobj->localmem == NULL)
        winobj->localmem =
            MemoryContextAllocZero(winobj->winstate->partcontext, sz);
    return winobj->localmem;
}

References Assert(), WindowObjectData::localmem, MemoryContextAllocZero(), WindowAggState::partcontext, WindowObjectIsValid, and WindowObjectData::winstate.

Referenced by rank_up(), window_cume_dist(), window_dense_rank(), window_ntile(), window_percent_rank(), and window_rank().

◆ WinGetPartitionRowCount()

int64 WinGetPartitionRowCount ( WindowObject winobj )

Definition at line 3266 of file nodeWindowAgg.c.

{
    Assert(WindowObjectIsValid(winobj));
    spool_tuples(winobj->winstate, -1);
    return winobj->winstate->spooled_rows;
}

References Assert(), spool_tuples(), WindowAggState::spooled_rows, WindowObjectIsValid, and WindowObjectData::winstate.

Referenced by window_cume_dist(), window_ntile(), and window_percent_rank().

◆ WinRowsArePeers()

bool WinRowsArePeers	(	WindowObject	winobj,
		int64	pos1,
		int64	pos2
	)

Definition at line 3319 of file nodeWindowAgg.c.

{
    WindowAggState *winstate;
    WindowAgg  *node;
    TupleTableSlot *slot1;
    TupleTableSlot *slot2;
    bool        res;
 
    Assert(WindowObjectIsValid(winobj));
    winstate = winobj->winstate;
    node = (WindowAgg *) winstate->ss.ps.plan;
 
    /* If no ORDER BY, all rows are peers; don't bother to fetch them */
    if (node->ordNumCols == 0)
        return true;
 
    /*
     * Note: OK to use temp_slot_2 here because we aren't calling any
     * frame-related functions (those tend to clobber temp_slot_2).
     */
    slot1 = winstate->temp_slot_1;
    slot2 = winstate->temp_slot_2;
 
    if (!window_gettupleslot(winobj, pos1, slot1))
        elog(ERROR, "specified position is out of window: " INT64_FORMAT,
             pos1);
    if (!window_gettupleslot(winobj, pos2, slot2))
        elog(ERROR, "specified position is out of window: " INT64_FORMAT,
             pos2);
 
    res = are_peers(winstate, slot1, slot2);
 
    ExecClearTuple(slot1);
    ExecClearTuple(slot2);
 
    return res;
}

References are_peers(), Assert(), elog, ERROR, ExecClearTuple(), if(), INT64_FORMAT, WindowAgg::ordNumCols, PlanState::plan, ScanState::ps, WindowAggState::ss, WindowAggState::temp_slot_1, WindowAggState::temp_slot_2, window_gettupleslot(), WindowObjectIsValid, and WindowObjectData::winstate.

Referenced by rank_up(), and window_cume_dist().

◆ WinSetMarkPosition()

void WinSetMarkPosition	(	WindowObject	winobj,
		int64	markpos
	)

Definition at line 3284 of file nodeWindowAgg.c.

{
    WindowAggState *winstate;
 
    Assert(WindowObjectIsValid(winobj));
    winstate = winobj->winstate;
 
    if (markpos < winobj->markpos)
        elog(ERROR, "cannot move WindowObject's mark position backward");
    tuplestore_select_read_pointer(winstate->buffer, winobj->markptr);
    if (markpos > winobj->markpos)
    {
        tuplestore_skiptuples(winstate->buffer,
                              markpos - winobj->markpos,
                              true);
        winobj->markpos = markpos;
    }
    tuplestore_select_read_pointer(winstate->buffer, winobj->readptr);
    if (markpos > winobj->seekpos)
    {
        tuplestore_skiptuples(winstate->buffer,
                              markpos - winobj->seekpos,
                              true);
        winobj->seekpos = markpos;
    }
}

References Assert(), WindowAggState::buffer, elog, ERROR, WindowObjectData::markpos, WindowObjectData::markptr, WindowObjectData::readptr, WindowObjectData::seekpos, tuplestore_select_read_pointer(), tuplestore_skiptuples(), WindowObjectIsValid, and WindowObjectData::winstate.

Referenced by eval_windowaggregates(), rank_up(), window_row_number(), WinGetFuncArgInFrame(), and WinGetFuncArgInPartition().

Data Structures

Typedefs

Functions

Typedef Documentation

◆ WindowObjectData

◆ WindowStatePerAggData

◆ WindowStatePerFuncData

Function Documentation

◆ advance_windowaggregate()

◆ advance_windowaggregate_base()

◆ are_peers()

◆ begin_partition()

◆ calculate_frame_offsets()

◆ eval_windowaggregates()

◆ eval_windowfunction()

◆ ExecEndWindowAgg()

◆ ExecInitWindowAgg()

◆ ExecReScanWindowAgg()

◆ ExecWindowAgg()

◆ finalize_windowaggregate()

◆ GetAggInitVal()

◆ initialize_peragg()

◆ initialize_windowaggregate()

◆ prepare_tuplestore()

◆ release_partition()

◆ row_is_in_frame()

◆ spool_tuples()

◆ update_frameheadpos()

◆ update_frametailpos()

◆ update_grouptailpos()

◆ window_gettupleslot()

◆ WinGetCurrentPosition()

◆ WinGetFuncArgCurrent()

◆ WinGetFuncArgInFrame()

◆ WinGetFuncArgInPartition()

◆ WinGetPartitionLocalMemory()

◆ WinGetPartitionRowCount()

◆ WinRowsArePeers()

◆ WinSetMarkPosition()