orderedsetaggs.c File Reference

#include "postgres.h"
#include <math.h>
#include "catalog/pg_aggregate.h"
#include "catalog/pg_operator.h"
#include "catalog/pg_type.h"
#include "executor/executor.h"
#include "miscadmin.h"
#include "nodes/nodeFuncs.h"
#include "optimizer/optimizer.h"
#include "utils/array.h"
#include "utils/fmgrprotos.h"
#include "utils/lsyscache.h"
#include "utils/tuplesort.h"

Include dependency graph for orderedsetaggs.c:

Go to the source code of this file.

Data Structures
struct	OSAPerQueryState
struct	OSAPerGroupState
struct	pct_info

Typedefs
typedef struct OSAPerQueryState	OSAPerQueryState
typedef struct OSAPerGroupState	OSAPerGroupState
typedef Datum(*	LerpFunc) (Datum lo, Datum hi, double pct)

Functions
static void	ordered_set_shutdown (Datum arg)
static OSAPerGroupState *	ordered_set_startup (FunctionCallInfo fcinfo, bool use_tuples)
Datum	ordered_set_transition (PG_FUNCTION_ARGS)
Datum	ordered_set_transition_multi (PG_FUNCTION_ARGS)
Datum	percentile_disc_final (PG_FUNCTION_ARGS)
static Datum	float8_lerp (Datum lo, Datum hi, double pct)
static Datum	interval_lerp (Datum lo, Datum hi, double pct)
static Datum	percentile_cont_final_common (FunctionCallInfo fcinfo, Oid expect_type, LerpFunc lerpfunc)
Datum	percentile_cont_float8_final (PG_FUNCTION_ARGS)
Datum	percentile_cont_interval_final (PG_FUNCTION_ARGS)
static int	pct_info_cmp (const void *pa, const void *pb)
static struct pct_info *	setup_pct_info (int num_percentiles, Datum *percentiles_datum, bool *percentiles_null, int64 rowcount, bool continuous)
Datum	percentile_disc_multi_final (PG_FUNCTION_ARGS)
static Datum	percentile_cont_multi_final_common (FunctionCallInfo fcinfo, Oid expect_type, int16 typLen, bool typByVal, char typAlign, LerpFunc lerpfunc)
Datum	percentile_cont_float8_multi_final (PG_FUNCTION_ARGS)
Datum	percentile_cont_interval_multi_final (PG_FUNCTION_ARGS)
Datum	mode_final (PG_FUNCTION_ARGS)
static void	hypothetical_check_argtypes (FunctionCallInfo fcinfo, int nargs, TupleDesc tupdesc)
static int64	hypothetical_rank_common (FunctionCallInfo fcinfo, int flag, int64 *number_of_rows)
Datum	hypothetical_rank_final (PG_FUNCTION_ARGS)
Datum	hypothetical_percent_rank_final (PG_FUNCTION_ARGS)
Datum	hypothetical_cume_dist_final (PG_FUNCTION_ARGS)
Datum	hypothetical_dense_rank_final (PG_FUNCTION_ARGS)

Typedef Documentation

LerpFunc

typedef Datum(* LerpFunc) (Datum lo, Datum hi, double pct)

Definition at line 500 of file orderedsetaggs.c.

OSAPerGroupState

typedef struct OSAPerGroupState OSAPerGroupState

OSAPerQueryState

typedef struct OSAPerQueryState OSAPerQueryState

Function Documentation

float8_lerp()

static Datum float8_lerp ( Datum  lo, Datum  hi, double  pct  )

static

Definition at line 503 of file orderedsetaggs.c.

{
    double      loval = DatumGetFloat8(lo);
    double      hival = DatumGetFloat8(hi);
 
    return Float8GetDatum(loval + (pct * (hival - loval)));
}

References DatumGetFloat8(), and Float8GetDatum().

Referenced by percentile_cont_float8_final(), and percentile_cont_float8_multi_final().

hypothetical_check_argtypes()

static void hypothetical_check_argtypes ( FunctionCallInfo  fcinfo, int  nargs, TupleDesc  tupdesc  )

static

Definition at line 1142 of file orderedsetaggs.c.

{
    int         i;
 
    /* check that we have an int4 flag column */
    if (!tupdesc ||
        (nargs + 1) != tupdesc->natts ||
        TupleDescAttr(tupdesc, nargs)->atttypid != INT4OID)
        elog(ERROR, "type mismatch in hypothetical-set function");
 
    /* check that direct args match in type with aggregated args */
    for (i = 0; i < nargs; i++)
    {
        Form_pg_attribute attr = TupleDescAttr(tupdesc, i);
 
        if (get_fn_expr_argtype(fcinfo->flinfo, i + 1) != attr->atttypid)
            elog(ERROR, "type mismatch in hypothetical-set function");
    }
}

References elog, ERROR, FunctionCallInfoBaseData::flinfo, get_fn_expr_argtype(), i, TupleDescData::natts, and TupleDescAttr().

Referenced by hypothetical_dense_rank_final(), and hypothetical_rank_common().

hypothetical_cume_dist_final()

Datum hypothetical_cume_dist_final

(

PG_FUNCTION_ARGS

)

Definition at line 1278 of file orderedsetaggs.c.

{
    int64       rank;
    int64       rowcount;
    double      result_val;
 
    rank = hypothetical_rank_common(fcinfo, 1, &rowcount);
 
    result_val = (double) (rank) / (double) (rowcount + 1);
 
    PG_RETURN_FLOAT8(result_val);
}

References hypothetical_rank_common(), and PG_RETURN_FLOAT8.

hypothetical_dense_rank_final()

Datum hypothetical_dense_rank_final

(

PG_FUNCTION_ARGS

)

Definition at line 1295 of file orderedsetaggs.c.

{
    ExprContext *econtext;
    ExprState  *compareTuple;
    int         nargs = PG_NARGS() - 1;
    int64       rank = 1;
    int64       duplicate_count = 0;
    OSAPerGroupState *osastate;
    int         numDistinctCols;
    Datum       abbrevVal = (Datum) 0;
    Datum       abbrevOld = (Datum) 0;
    TupleTableSlot *slot;
    TupleTableSlot *extraslot;
    TupleTableSlot *slot2;
    int         i;
 
    Assert(AggCheckCallContext(fcinfo, NULL) == AGG_CONTEXT_AGGREGATE);
 
    /* If there were no regular rows, the rank is always 1 */
    if (PG_ARGISNULL(0))
        PG_RETURN_INT64(rank);
 
    osastate = (OSAPerGroupState *) PG_GETARG_POINTER(0);
    econtext = osastate->qstate->econtext;
    if (!econtext)
    {
        MemoryContext oldcontext;
 
        /* Make sure to we create econtext under correct parent context. */
        oldcontext = MemoryContextSwitchTo(osastate->qstate->qcontext);
        osastate->qstate->econtext = CreateStandaloneExprContext();
        econtext = osastate->qstate->econtext;
        MemoryContextSwitchTo(oldcontext);
    }
 
    /* Adjust nargs to be the number of direct (or aggregated) args */
    if (nargs % 2 != 0)
        elog(ERROR, "wrong number of arguments in hypothetical-set function");
    nargs /= 2;
 
    hypothetical_check_argtypes(fcinfo, nargs, osastate->qstate->tupdesc);
 
    /*
     * When comparing tuples, we can omit the flag column since we will only
     * compare rows with flag == 0.
     */
    numDistinctCols = osastate->qstate->numSortCols - 1;
 
    /* Build tuple comparator, if we didn't already */
    compareTuple = osastate->qstate->compareTuple;
    if (compareTuple == NULL)
    {
        AttrNumber *sortColIdx = osastate->qstate->sortColIdx;
        MemoryContext oldContext;
 
        oldContext = MemoryContextSwitchTo(osastate->qstate->qcontext);
        compareTuple = execTuplesMatchPrepare(osastate->qstate->tupdesc,
                                              numDistinctCols,
                                              sortColIdx,
                                              osastate->qstate->eqOperators,
                                              osastate->qstate->sortCollations,
                                              NULL);
        MemoryContextSwitchTo(oldContext);
        osastate->qstate->compareTuple = compareTuple;
    }
 
    /* because we need a hypothetical row, we can't share transition state */
    Assert(!osastate->sort_done);
 
    /* insert the hypothetical row into the sort */
    slot = osastate->qstate->tupslot;
    ExecClearTuple(slot);
    for (i = 0; i < nargs; i++)
    {
        slot->tts_values[i] = PG_GETARG_DATUM(i + 1);
        slot->tts_isnull[i] = PG_ARGISNULL(i + 1);
    }
    slot->tts_values[i] = Int32GetDatum(-1);
    slot->tts_isnull[i] = false;
    ExecStoreVirtualTuple(slot);
 
    tuplesort_puttupleslot(osastate->sortstate, slot);
 
    /* finish the sort */
    tuplesort_performsort(osastate->sortstate);
    osastate->sort_done = true;
 
    /*
     * We alternate fetching into tupslot and extraslot so that we have the
     * previous row available for comparisons.  This is accomplished by
     * swapping the slot pointer variables after each row.
     */
    extraslot = MakeSingleTupleTableSlot(osastate->qstate->tupdesc,
                                         &TTSOpsMinimalTuple);
    slot2 = extraslot;
 
    /* iterate till we find the hypothetical row */
    while (tuplesort_gettupleslot(osastate->sortstate, true, true, slot,
                                  &abbrevVal))
    {
        bool        isnull;
        Datum       d = slot_getattr(slot, nargs + 1, &isnull);
        TupleTableSlot *tmpslot;
 
        if (!isnull && DatumGetInt32(d) != 0)
            break;
 
        /* count non-distinct tuples */
        econtext->ecxt_outertuple = slot;
        econtext->ecxt_innertuple = slot2;
 
        if (!TupIsNull(slot2) &&
            abbrevVal == abbrevOld &&
            ExecQualAndReset(compareTuple, econtext))
            duplicate_count++;
 
        tmpslot = slot2;
        slot2 = slot;
        slot = tmpslot;
        /* avoid ExecQual() calls by reusing abbreviated keys */
        abbrevOld = abbrevVal;
 
        rank++;
 
        CHECK_FOR_INTERRUPTS();
    }
 
    ExecClearTuple(slot);
    ExecClearTuple(slot2);
 
    ExecDropSingleTupleTableSlot(extraslot);
 
    rank = rank - duplicate_count;
 
    PG_RETURN_INT64(rank);
}

References AGG_CONTEXT_AGGREGATE, AggCheckCallContext(), Assert(), CHECK_FOR_INTERRUPTS, OSAPerQueryState::compareTuple, CreateStandaloneExprContext(), DatumGetInt32(), OSAPerQueryState::econtext, ExprContext::ecxt_innertuple, ExprContext::ecxt_outertuple, elog, OSAPerQueryState::eqOperators, ERROR, ExecClearTuple(), ExecDropSingleTupleTableSlot(), ExecQualAndReset(), ExecStoreVirtualTuple(), execTuplesMatchPrepare(), hypothetical_check_argtypes(), i, Int32GetDatum(), MakeSingleTupleTableSlot(), MemoryContextSwitchTo(), OSAPerQueryState::numSortCols, PG_ARGISNULL, PG_GETARG_DATUM, PG_GETARG_POINTER, PG_NARGS, PG_RETURN_INT64, OSAPerQueryState::qcontext, OSAPerGroupState::qstate, slot_getattr(), OSAPerGroupState::sort_done, OSAPerQueryState::sortColIdx, OSAPerQueryState::sortCollations, OSAPerGroupState::sortstate, TupleTableSlot::tts_isnull, TupleTableSlot::tts_values, TTSOpsMinimalTuple, OSAPerQueryState::tupdesc, TupIsNull, tuplesort_gettupleslot(), tuplesort_performsort(), tuplesort_puttupleslot(), and OSAPerQueryState::tupslot.

hypothetical_percent_rank_final()

Datum hypothetical_percent_rank_final

(

PG_FUNCTION_ARGS

)

Definition at line 1258 of file orderedsetaggs.c.

{
    int64       rank;
    int64       rowcount;
    double      result_val;
 
    rank = hypothetical_rank_common(fcinfo, -1, &rowcount);
 
    if (rowcount == 0)
        PG_RETURN_FLOAT8(0);
 
    result_val = (double) (rank - 1) / (double) (rowcount);
 
    PG_RETURN_FLOAT8(result_val);
}

References hypothetical_rank_common(), and PG_RETURN_FLOAT8.

hypothetical_rank_common()

static int64 hypothetical_rank_common ( FunctionCallInfo  fcinfo, int  flag, int64 *  number_of_rows  )

static

Definition at line 1171 of file orderedsetaggs.c.

{
    int         nargs = PG_NARGS() - 1;
    int64       rank = 1;
    OSAPerGroupState *osastate;
    TupleTableSlot *slot;
    int         i;
 
    Assert(AggCheckCallContext(fcinfo, NULL) == AGG_CONTEXT_AGGREGATE);
 
    /* If there were no regular rows, the rank is always 1 */
    if (PG_ARGISNULL(0))
    {
        *number_of_rows = 0;
        return 1;
    }
 
    osastate = (OSAPerGroupState *) PG_GETARG_POINTER(0);
    *number_of_rows = osastate->number_of_rows;
 
    /* Adjust nargs to be the number of direct (or aggregated) args */
    if (nargs % 2 != 0)
        elog(ERROR, "wrong number of arguments in hypothetical-set function");
    nargs /= 2;
 
    hypothetical_check_argtypes(fcinfo, nargs, osastate->qstate->tupdesc);
 
    /* because we need a hypothetical row, we can't share transition state */
    Assert(!osastate->sort_done);
 
    /* insert the hypothetical row into the sort */
    slot = osastate->qstate->tupslot;
    ExecClearTuple(slot);
    for (i = 0; i < nargs; i++)
    {
        slot->tts_values[i] = PG_GETARG_DATUM(i + 1);
        slot->tts_isnull[i] = PG_ARGISNULL(i + 1);
    }
    slot->tts_values[i] = Int32GetDatum(flag);
    slot->tts_isnull[i] = false;
    ExecStoreVirtualTuple(slot);
 
    tuplesort_puttupleslot(osastate->sortstate, slot);
 
    /* finish the sort */
    tuplesort_performsort(osastate->sortstate);
    osastate->sort_done = true;
 
    /* iterate till we find the hypothetical row */
    while (tuplesort_gettupleslot(osastate->sortstate, true, true, slot, NULL))
    {
        bool        isnull;
        Datum       d = slot_getattr(slot, nargs + 1, &isnull);
 
        if (!isnull && DatumGetInt32(d) != 0)
            break;
 
        rank++;
 
        CHECK_FOR_INTERRUPTS();
    }
 
    ExecClearTuple(slot);
 
    return rank;
}

References AGG_CONTEXT_AGGREGATE, AggCheckCallContext(), Assert(), CHECK_FOR_INTERRUPTS, DatumGetInt32(), elog, ERROR, ExecClearTuple(), ExecStoreVirtualTuple(), flag(), hypothetical_check_argtypes(), i, Int32GetDatum(), OSAPerGroupState::number_of_rows, PG_ARGISNULL, PG_GETARG_DATUM, PG_GETARG_POINTER, PG_NARGS, OSAPerGroupState::qstate, slot_getattr(), OSAPerGroupState::sort_done, OSAPerGroupState::sortstate, TupleTableSlot::tts_isnull, TupleTableSlot::tts_values, OSAPerQueryState::tupdesc, tuplesort_gettupleslot(), tuplesort_performsort(), tuplesort_puttupleslot(), and OSAPerQueryState::tupslot.

Referenced by hypothetical_cume_dist_final(), hypothetical_percent_rank_final(), and hypothetical_rank_final().

hypothetical_rank_final()

Datum hypothetical_rank_final

(

PG_FUNCTION_ARGS

)

Definition at line 1244 of file orderedsetaggs.c.

{
    int64       rank;
    int64       rowcount;
 
    rank = hypothetical_rank_common(fcinfo, -1, &rowcount);
 
    PG_RETURN_INT64(rank);
}

References hypothetical_rank_common(), and PG_RETURN_INT64.

interval_lerp()

static Datum interval_lerp ( Datum  lo, Datum  hi, double  pct  )

static

Definition at line 512 of file orderedsetaggs.c.

{
    Datum       diff_result = DirectFunctionCall2(interval_mi, hi, lo);
    Datum       mul_result = DirectFunctionCall2(interval_mul,
                                                 diff_result,
                                                 Float8GetDatumFast(pct));
 
    return DirectFunctionCall2(interval_pl, mul_result, lo);
}

References DirectFunctionCall2, Float8GetDatumFast, interval_mi(), interval_mul(), and interval_pl().

Referenced by percentile_cont_interval_final(), and percentile_cont_interval_multi_final().

mode_final()

Datum mode_final

(

PG_FUNCTION_ARGS

)

Definition at line 1033 of file orderedsetaggs.c.

{
    OSAPerGroupState *osastate;
    Datum       val;
    bool        isnull;
    Datum       mode_val = (Datum) 0;
    int64       mode_freq = 0;
    Datum       last_val = (Datum) 0;
    int64       last_val_freq = 0;
    bool        last_val_is_mode = false;
    FmgrInfo   *equalfn;
    Datum       abbrev_val = (Datum) 0;
    Datum       last_abbrev_val = (Datum) 0;
    bool        shouldfree;
 
    Assert(AggCheckCallContext(fcinfo, NULL) == AGG_CONTEXT_AGGREGATE);
 
    /* If there were no regular rows, the result is NULL */
    if (PG_ARGISNULL(0))
        PG_RETURN_NULL();
 
    osastate = (OSAPerGroupState *) PG_GETARG_POINTER(0);
 
    /* number_of_rows could be zero if we only saw NULL input values */
    if (osastate->number_of_rows == 0)
        PG_RETURN_NULL();
 
    /* Look up the equality function for the datatype, if we didn't already */
    equalfn = &(osastate->qstate->equalfn);
    if (!OidIsValid(equalfn->fn_oid))
        fmgr_info_cxt(get_opcode(osastate->qstate->eqOperator), equalfn,
                      osastate->qstate->qcontext);
 
    shouldfree = !(osastate->qstate->typByVal);
 
    /* Finish the sort, or rescan if we already did */
    if (!osastate->sort_done)
    {
        tuplesort_performsort(osastate->sortstate);
        osastate->sort_done = true;
    }
    else
        tuplesort_rescan(osastate->sortstate);
 
    /* Scan tuples and count frequencies */
    while (tuplesort_getdatum(osastate->sortstate, true, true, &val, &isnull,
                              &abbrev_val))
    {
        /* we don't expect any nulls, but ignore them if found */
        if (isnull)
            continue;
 
        if (last_val_freq == 0)
        {
            /* first nonnull value - it's the mode for now */
            mode_val = last_val = val;
            mode_freq = last_val_freq = 1;
            last_val_is_mode = true;
            last_abbrev_val = abbrev_val;
        }
        else if (abbrev_val == last_abbrev_val &&
                 DatumGetBool(FunctionCall2Coll(equalfn, PG_GET_COLLATION(), val, last_val)))
        {
            /* value equal to previous value, count it */
            if (last_val_is_mode)
                mode_freq++;    /* needn't maintain last_val_freq */
            else if (++last_val_freq > mode_freq)
            {
                /* last_val becomes new mode */
                if (shouldfree)
                    pfree(DatumGetPointer(mode_val));
                mode_val = last_val;
                mode_freq = last_val_freq;
                last_val_is_mode = true;
            }
            if (shouldfree)
                pfree(DatumGetPointer(val));
        }
        else
        {
            /* val should replace last_val */
            if (shouldfree && !last_val_is_mode)
                pfree(DatumGetPointer(last_val));
            last_val = val;
            /* avoid equality function calls by reusing abbreviated keys */
            last_abbrev_val = abbrev_val;
            last_val_freq = 1;
            last_val_is_mode = false;
        }
 
        CHECK_FOR_INTERRUPTS();
    }
 
    if (shouldfree && !last_val_is_mode)
        pfree(DatumGetPointer(last_val));
 
    if (mode_freq)
        PG_RETURN_DATUM(mode_val);
    else
        PG_RETURN_NULL();
}

References AGG_CONTEXT_AGGREGATE, AggCheckCallContext(), Assert(), CHECK_FOR_INTERRUPTS, DatumGetBool(), DatumGetPointer(), OSAPerQueryState::eqOperator, OSAPerQueryState::equalfn, fmgr_info_cxt(), FmgrInfo::fn_oid, FunctionCall2Coll(), get_opcode(), OSAPerGroupState::number_of_rows, OidIsValid, pfree(), PG_ARGISNULL, PG_GET_COLLATION, PG_GETARG_POINTER, PG_RETURN_DATUM, PG_RETURN_NULL, OSAPerQueryState::qcontext, OSAPerGroupState::qstate, OSAPerGroupState::sort_done, OSAPerGroupState::sortstate, tuplesort_getdatum(), tuplesort_performsort(), tuplesort_rescan(), OSAPerQueryState::typByVal, and val.

ordered_set_shutdown()

static void ordered_set_shutdown ( Datum  arg )

static

Definition at line 339 of file orderedsetaggs.c.

{
    OSAPerGroupState *osastate = (OSAPerGroupState *) DatumGetPointer(arg);
 
    /* Tuplesort object might have temp files. */
    if (osastate->sortstate)
        tuplesort_end(osastate->sortstate);
    osastate->sortstate = NULL;
    /* The tupleslot probably can't be holding a pin, but let's be safe. */
    if (osastate->qstate->tupslot)
        ExecClearTuple(osastate->qstate->tupslot);
}

References arg, DatumGetPointer(), ExecClearTuple(), OSAPerGroupState::qstate, OSAPerGroupState::sortstate, tuplesort_end(), and OSAPerQueryState::tupslot.

Referenced by ordered_set_startup().

ordered_set_startup()

static OSAPerGroupState * ordered_set_startup ( FunctionCallInfo  fcinfo, bool  use_tuples  )

static

Definition at line 113 of file orderedsetaggs.c.

{
    OSAPerGroupState *osastate;
    OSAPerQueryState *qstate;
    MemoryContext gcontext;
    MemoryContext oldcontext;
    int         tuplesortopt;
 
    /*
     * Check we're called as aggregate (and not a window function), and get
     * the Agg node's group-lifespan context (which might change from group to
     * group, so we shouldn't cache it in the per-query state).
     */
    if (AggCheckCallContext(fcinfo, &gcontext) != AGG_CONTEXT_AGGREGATE)
        elog(ERROR, "ordered-set aggregate called in non-aggregate context");
 
    /*
     * We keep a link to the per-query state in fn_extra; if it's not there,
     * create it, and do the per-query setup we need.
     */
    qstate = (OSAPerQueryState *) fcinfo->flinfo->fn_extra;
    if (qstate == NULL)
    {
        Aggref     *aggref;
        MemoryContext qcontext;
        List       *sortlist;
        int         numSortCols;
 
        /* Get the Aggref so we can examine aggregate's arguments */
        aggref = AggGetAggref(fcinfo);
        if (!aggref)
            elog(ERROR, "ordered-set aggregate called in non-aggregate context");
        if (!AGGKIND_IS_ORDERED_SET(aggref->aggkind))
            elog(ERROR, "ordered-set aggregate support function called for non-ordered-set aggregate");
 
        /*
         * Prepare per-query structures in the fn_mcxt, which we assume is the
         * executor's per-query context; in any case it's the right place to
         * keep anything found via fn_extra.
         */
        qcontext = fcinfo->flinfo->fn_mcxt;
        oldcontext = MemoryContextSwitchTo(qcontext);
 
        qstate = (OSAPerQueryState *) palloc0(sizeof(OSAPerQueryState));
        qstate->aggref = aggref;
        qstate->qcontext = qcontext;
 
        /* We need to support rescans if the trans state is shared */
        qstate->rescan_needed = AggStateIsShared(fcinfo);
 
        /* Extract the sort information */
        sortlist = aggref->aggorder;
        numSortCols = list_length(sortlist);
 
        if (use_tuples)
        {
            bool        ishypothetical = (aggref->aggkind == AGGKIND_HYPOTHETICAL);
            ListCell   *lc;
            int         i;
 
            if (ishypothetical)
                numSortCols++;  /* make space for flag column */
            qstate->numSortCols = numSortCols;
            qstate->sortColIdx = (AttrNumber *) palloc(numSortCols * sizeof(AttrNumber));
            qstate->sortOperators = (Oid *) palloc(numSortCols * sizeof(Oid));
            qstate->eqOperators = (Oid *) palloc(numSortCols * sizeof(Oid));
            qstate->sortCollations = (Oid *) palloc(numSortCols * sizeof(Oid));
            qstate->sortNullsFirsts = (bool *) palloc(numSortCols * sizeof(bool));
 
            i = 0;
            foreach(lc, sortlist)
            {
                SortGroupClause *sortcl = (SortGroupClause *) lfirst(lc);
                TargetEntry *tle = get_sortgroupclause_tle(sortcl,
                                                           aggref->args);
 
                /* the parser should have made sure of this */
                Assert(OidIsValid(sortcl->sortop));
 
                qstate->sortColIdx[i] = tle->resno;
                qstate->sortOperators[i] = sortcl->sortop;
                qstate->eqOperators[i] = sortcl->eqop;
                qstate->sortCollations[i] = exprCollation((Node *) tle->expr);
                qstate->sortNullsFirsts[i] = sortcl->nulls_first;
                i++;
            }
 
            if (ishypothetical)
            {
                /* Add an integer flag column as the last sort column */
                qstate->sortColIdx[i] = list_length(aggref->args) + 1;
                qstate->sortOperators[i] = Int4LessOperator;
                qstate->eqOperators[i] = Int4EqualOperator;
                qstate->sortCollations[i] = InvalidOid;
                qstate->sortNullsFirsts[i] = false;
                i++;
            }
 
            Assert(i == numSortCols);
 
            /*
             * Get a tupledesc corresponding to the aggregated inputs
             * (including sort expressions) of the agg.
             */
            qstate->tupdesc = ExecTypeFromTL(aggref->args);
 
            /* If we need a flag column, hack the tupledesc to include that */
            if (ishypothetical)
            {
                TupleDesc   newdesc;
                int         natts = qstate->tupdesc->natts;
 
                newdesc = CreateTemplateTupleDesc(natts + 1);
                for (i = 1; i <= natts; i++)
                    TupleDescCopyEntry(newdesc, i, qstate->tupdesc, i);
 
                TupleDescInitEntry(newdesc,
                                   (AttrNumber) ++natts,
                                   "flag",
                                   INT4OID,
                                   -1,
                                   0);
 
                FreeTupleDesc(qstate->tupdesc);
                qstate->tupdesc = newdesc;
            }
 
            /* Create slot we'll use to store/retrieve rows */
            qstate->tupslot = MakeSingleTupleTableSlot(qstate->tupdesc,
                                                       &TTSOpsMinimalTuple);
        }
        else
        {
            /* Sort single datums */
            SortGroupClause *sortcl;
            TargetEntry *tle;
 
            if (numSortCols != 1 || aggref->aggkind == AGGKIND_HYPOTHETICAL)
                elog(ERROR, "ordered-set aggregate support function does not support multiple aggregated columns");
 
            sortcl = (SortGroupClause *) linitial(sortlist);
            tle = get_sortgroupclause_tle(sortcl, aggref->args);
 
            /* the parser should have made sure of this */
            Assert(OidIsValid(sortcl->sortop));
 
            /* Save sort ordering info */
            qstate->sortColType = exprType((Node *) tle->expr);
            qstate->sortOperator = sortcl->sortop;
            qstate->eqOperator = sortcl->eqop;
            qstate->sortCollation = exprCollation((Node *) tle->expr);
            qstate->sortNullsFirst = sortcl->nulls_first;
 
            /* Save datatype info */
            get_typlenbyvalalign(qstate->sortColType,
                                 &qstate->typLen,
                                 &qstate->typByVal,
                                 &qstate->typAlign);
        }
 
        fcinfo->flinfo->fn_extra = qstate;
 
        MemoryContextSwitchTo(oldcontext);
    }
 
    /* Now build the stuff we need in group-lifespan context */
    oldcontext = MemoryContextSwitchTo(gcontext);
 
    osastate = (OSAPerGroupState *) palloc(sizeof(OSAPerGroupState));
    osastate->qstate = qstate;
    osastate->gcontext = gcontext;
 
    tuplesortopt = TUPLESORT_NONE;
 
    if (qstate->rescan_needed)
        tuplesortopt |= TUPLESORT_RANDOMACCESS;
 
    /*
     * Initialize tuplesort object.
     */
    if (use_tuples)
        osastate->sortstate = tuplesort_begin_heap(qstate->tupdesc,
                                                   qstate->numSortCols,
                                                   qstate->sortColIdx,
                                                   qstate->sortOperators,
                                                   qstate->sortCollations,
                                                   qstate->sortNullsFirsts,
                                                   work_mem,
                                                   NULL,
                                                   tuplesortopt);
    else
        osastate->sortstate = tuplesort_begin_datum(qstate->sortColType,
                                                    qstate->sortOperator,
                                                    qstate->sortCollation,
                                                    qstate->sortNullsFirst,
                                                    work_mem,
                                                    NULL,
                                                    tuplesortopt);
 
    osastate->number_of_rows = 0;
    osastate->sort_done = false;
 
    /* Now register a shutdown callback to clean things up at end of group */
    AggRegisterCallback(fcinfo,
                        ordered_set_shutdown,
                        PointerGetDatum(osastate));
 
    MemoryContextSwitchTo(oldcontext);
 
    return osastate;
}

References AGG_CONTEXT_AGGREGATE, AggCheckCallContext(), AggGetAggref(), Aggref::aggorder, OSAPerQueryState::aggref, AggRegisterCallback(), AggStateIsShared(), Aggref::args, Assert(), CreateTemplateTupleDesc(), elog, SortGroupClause::eqop, OSAPerQueryState::eqOperator, OSAPerQueryState::eqOperators, ERROR, ExecTypeFromTL(), TargetEntry::expr, exprCollation(), exprType(), FunctionCallInfoBaseData::flinfo, FmgrInfo::fn_extra, FmgrInfo::fn_mcxt, FreeTupleDesc(), OSAPerGroupState::gcontext, get_sortgroupclause_tle(), get_typlenbyvalalign(), i, if(), InvalidOid, lfirst, linitial, list_length(), MakeSingleTupleTableSlot(), MemoryContextSwitchTo(), TupleDescData::natts, SortGroupClause::nulls_first, OSAPerGroupState::number_of_rows, OSAPerQueryState::numSortCols, OidIsValid, ordered_set_shutdown(), palloc(), palloc0(), PointerGetDatum(), OSAPerQueryState::qcontext, OSAPerGroupState::qstate, OSAPerQueryState::rescan_needed, TargetEntry::resno, OSAPerGroupState::sort_done, OSAPerQueryState::sortColIdx, OSAPerQueryState::sortCollation, OSAPerQueryState::sortCollations, OSAPerQueryState::sortColType, OSAPerQueryState::sortNullsFirst, OSAPerQueryState::sortNullsFirsts, SortGroupClause::sortop, OSAPerQueryState::sortOperator, OSAPerQueryState::sortOperators, OSAPerGroupState::sortstate, TTSOpsMinimalTuple, OSAPerQueryState::tupdesc, TupleDescCopyEntry(), TupleDescInitEntry(), tuplesort_begin_datum(), tuplesort_begin_heap(), TUPLESORT_NONE, TUPLESORT_RANDOMACCESS, OSAPerQueryState::tupslot, OSAPerQueryState::typAlign, OSAPerQueryState::typByVal, OSAPerQueryState::typLen, and work_mem.

Referenced by ordered_set_transition(), and ordered_set_transition_multi().

ordered_set_transition()

Datum ordered_set_transition

(

PG_FUNCTION_ARGS

)

Definition at line 358 of file orderedsetaggs.c.

{
    OSAPerGroupState *osastate;
 
    /* If first call, create the transition state workspace */
    if (PG_ARGISNULL(0))
        osastate = ordered_set_startup(fcinfo, false);
    else
        osastate = (OSAPerGroupState *) PG_GETARG_POINTER(0);
 
    /* Load the datum into the tuplesort object, but only if it's not null */
    if (!PG_ARGISNULL(1))
    {
        tuplesort_putdatum(osastate->sortstate, PG_GETARG_DATUM(1), false);
        osastate->number_of_rows++;
    }
 
    PG_RETURN_POINTER(osastate);
}

References OSAPerGroupState::number_of_rows, ordered_set_startup(), PG_ARGISNULL, PG_GETARG_DATUM, PG_GETARG_POINTER, PG_RETURN_POINTER, OSAPerGroupState::sortstate, and tuplesort_putdatum().

ordered_set_transition_multi()

Datum ordered_set_transition_multi

(

PG_FUNCTION_ARGS

)

Definition at line 383 of file orderedsetaggs.c.

{
    OSAPerGroupState *osastate;
    TupleTableSlot *slot;
    int         nargs;
    int         i;
 
    /* If first call, create the transition state workspace */
    if (PG_ARGISNULL(0))
        osastate = ordered_set_startup(fcinfo, true);
    else
        osastate = (OSAPerGroupState *) PG_GETARG_POINTER(0);
 
    /* Form a tuple from all the other inputs besides the transition value */
    slot = osastate->qstate->tupslot;
    ExecClearTuple(slot);
    nargs = PG_NARGS() - 1;
    for (i = 0; i < nargs; i++)
    {
        slot->tts_values[i] = PG_GETARG_DATUM(i + 1);
        slot->tts_isnull[i] = PG_ARGISNULL(i + 1);
    }
    if (osastate->qstate->aggref->aggkind == AGGKIND_HYPOTHETICAL)
    {
        /* Add a zero flag value to mark this row as a normal input row */
        slot->tts_values[i] = Int32GetDatum(0);
        slot->tts_isnull[i] = false;
        i++;
    }
    Assert(i == slot->tts_tupleDescriptor->natts);
    ExecStoreVirtualTuple(slot);
 
    /* Load the row into the tuplesort object */
    tuplesort_puttupleslot(osastate->sortstate, slot);
    osastate->number_of_rows++;
 
    PG_RETURN_POINTER(osastate);
}

References OSAPerQueryState::aggref, Assert(), ExecClearTuple(), ExecStoreVirtualTuple(), i, Int32GetDatum(), TupleDescData::natts, OSAPerGroupState::number_of_rows, ordered_set_startup(), PG_ARGISNULL, PG_GETARG_DATUM, PG_GETARG_POINTER, PG_NARGS, PG_RETURN_POINTER, OSAPerGroupState::qstate, OSAPerGroupState::sortstate, TupleTableSlot::tts_isnull, TupleTableSlot::tts_tupleDescriptor, TupleTableSlot::tts_values, tuplesort_puttupleslot(), and OSAPerQueryState::tupslot.

pct_info_cmp()

static int pct_info_cmp ( const void *  pa, const void *  pb  )

static

Definition at line 646 of file orderedsetaggs.c.

{
    const struct pct_info *a = (const struct pct_info *) pa;
    const struct pct_info *b = (const struct pct_info *) pb;
 
    if (a->first_row != b->first_row)
        return (a->first_row < b->first_row) ? -1 : 1;
    if (a->second_row != b->second_row)
        return (a->second_row < b->second_row) ? -1 : 1;
    return 0;
}

References a, and b.

Referenced by setup_pct_info().

percentile_cont_final_common()

static Datum percentile_cont_final_common ( FunctionCallInfo  fcinfo, Oid  expect_type, LerpFunc  lerpfunc  )

static

Definition at line 526 of file orderedsetaggs.c.

{
    OSAPerGroupState *osastate;
    double      percentile;
    int64       first_row = 0;
    int64       second_row = 0;
    Datum       val;
    Datum       first_val;
    Datum       second_val;
    double      proportion;
    bool        isnull;
 
    Assert(AggCheckCallContext(fcinfo, NULL) == AGG_CONTEXT_AGGREGATE);
 
    /* Get and check the percentile argument */
    if (PG_ARGISNULL(1))
        PG_RETURN_NULL();
 
    percentile = PG_GETARG_FLOAT8(1);
 
    if (percentile < 0 || percentile > 1 || isnan(percentile))
        ereport(ERROR,
                (errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
                 errmsg("percentile value %g is not between 0 and 1",
                        percentile)));
 
    /* If there were no regular rows, the result is NULL */
    if (PG_ARGISNULL(0))
        PG_RETURN_NULL();
 
    osastate = (OSAPerGroupState *) PG_GETARG_POINTER(0);
 
    /* number_of_rows could be zero if we only saw NULL input values */
    if (osastate->number_of_rows == 0)
        PG_RETURN_NULL();
 
    Assert(expect_type == osastate->qstate->sortColType);
 
    /* Finish the sort, or rescan if we already did */
    if (!osastate->sort_done)
    {
        tuplesort_performsort(osastate->sortstate);
        osastate->sort_done = true;
    }
    else
        tuplesort_rescan(osastate->sortstate);
 
    first_row = floor(percentile * (osastate->number_of_rows - 1));
    second_row = ceil(percentile * (osastate->number_of_rows - 1));
 
    Assert(first_row < osastate->number_of_rows);
 
    if (!tuplesort_skiptuples(osastate->sortstate, first_row, true))
        elog(ERROR, "missing row in percentile_cont");
 
    if (!tuplesort_getdatum(osastate->sortstate, true, true, &first_val,
                            &isnull, NULL))
        elog(ERROR, "missing row in percentile_cont");
    if (isnull)
        PG_RETURN_NULL();
 
    if (first_row == second_row)
    {
        val = first_val;
    }
    else
    {
        if (!tuplesort_getdatum(osastate->sortstate, true, true, &second_val,
                                &isnull, NULL))
            elog(ERROR, "missing row in percentile_cont");
 
        if (isnull)
            PG_RETURN_NULL();
 
        proportion = (percentile * (osastate->number_of_rows - 1)) - first_row;
        val = lerpfunc(first_val, second_val, proportion);
    }
 
    PG_RETURN_DATUM(val);
}

References AGG_CONTEXT_AGGREGATE, AggCheckCallContext(), Assert(), elog, ereport, errcode(), errmsg(), ERROR, OSAPerGroupState::number_of_rows, PG_ARGISNULL, PG_GETARG_FLOAT8, PG_GETARG_POINTER, PG_RETURN_DATUM, PG_RETURN_NULL, OSAPerGroupState::qstate, OSAPerGroupState::sort_done, OSAPerQueryState::sortColType, OSAPerGroupState::sortstate, tuplesort_getdatum(), tuplesort_performsort(), tuplesort_rescan(), tuplesort_skiptuples(), and val.

Referenced by percentile_cont_float8_final(), and percentile_cont_interval_final().

percentile_cont_float8_final()

Datum percentile_cont_float8_final

(

PG_FUNCTION_ARGS

)

Definition at line 613 of file orderedsetaggs.c.

{
    return percentile_cont_final_common(fcinfo, FLOAT8OID, float8_lerp);
}

References float8_lerp(), and percentile_cont_final_common().

percentile_cont_float8_multi_final()

Datum percentile_cont_float8_multi_final

(

PG_FUNCTION_ARGS

)

Definition at line 1004 of file orderedsetaggs.c.

{
    return percentile_cont_multi_final_common(fcinfo,
                                              FLOAT8OID,
    /* hard-wired info on type float8 */
                                              sizeof(float8),
                                              FLOAT8PASSBYVAL,
                                              TYPALIGN_DOUBLE,
                                              float8_lerp);
}

References float8_lerp(), FLOAT8PASSBYVAL, and percentile_cont_multi_final_common().

percentile_cont_interval_final()

Datum percentile_cont_interval_final

(

PG_FUNCTION_ARGS

)

Definition at line 622 of file orderedsetaggs.c.

{
    return percentile_cont_final_common(fcinfo, INTERVALOID, interval_lerp);
}

References interval_lerp(), and percentile_cont_final_common().

percentile_cont_interval_multi_final()

Datum percentile_cont_interval_multi_final

(

PG_FUNCTION_ARGS

)

Definition at line 1019 of file orderedsetaggs.c.

{
    return percentile_cont_multi_final_common(fcinfo,
                                              INTERVALOID,
    /* hard-wired info on type interval */
                                              16, false, TYPALIGN_DOUBLE,
                                              interval_lerp);
}

References interval_lerp(), and percentile_cont_multi_final_common().

percentile_cont_multi_final_common()

static Datum percentile_cont_multi_final_common ( FunctionCallInfo  fcinfo, Oid  expect_type, int16  typLen, bool  typByVal, char  typAlign, LerpFunc  lerpfunc  )

static

Definition at line 848 of file orderedsetaggs.c.

{
    OSAPerGroupState *osastate;
    ArrayType  *param;
    Datum      *percentiles_datum;
    bool       *percentiles_null;
    int         num_percentiles;
    struct pct_info *pct_info;
    Datum      *result_datum;
    bool       *result_isnull;
    int64       rownum = 0;
    Datum       first_val = (Datum) 0;
    Datum       second_val = (Datum) 0;
    bool        isnull;
    int         i;
 
    Assert(AggCheckCallContext(fcinfo, NULL) == AGG_CONTEXT_AGGREGATE);
 
    /* If there were no regular rows, the result is NULL */
    if (PG_ARGISNULL(0))
        PG_RETURN_NULL();
 
    osastate = (OSAPerGroupState *) PG_GETARG_POINTER(0);
 
    /* number_of_rows could be zero if we only saw NULL input values */
    if (osastate->number_of_rows == 0)
        PG_RETURN_NULL();
 
    Assert(expect_type == osastate->qstate->sortColType);
 
    /* Deconstruct the percentile-array input */
    if (PG_ARGISNULL(1))
        PG_RETURN_NULL();
    param = PG_GETARG_ARRAYTYPE_P(1);
 
    deconstruct_array_builtin(param, FLOAT8OID,
                              &percentiles_datum,
                              &percentiles_null,
                              &num_percentiles);
 
    if (num_percentiles == 0)
        PG_RETURN_POINTER(construct_empty_array(osastate->qstate->sortColType));
 
    pct_info = setup_pct_info(num_percentiles,
                              percentiles_datum,
                              percentiles_null,
                              osastate->number_of_rows,
                              true);
 
    result_datum = (Datum *) palloc(num_percentiles * sizeof(Datum));
    result_isnull = (bool *) palloc(num_percentiles * sizeof(bool));
 
    /*
     * Start by dealing with any nulls in the param array - those are sorted
     * to the front on row=0, so set the corresponding result indexes to null
     */
    for (i = 0; i < num_percentiles; i++)
    {
        int         idx = pct_info[i].idx;
 
        if (pct_info[i].first_row > 0)
            break;
 
        result_datum[idx] = (Datum) 0;
        result_isnull[idx] = true;
    }
 
    /*
     * If there's anything left after doing the nulls, then grind the input
     * and extract the needed values
     */
    if (i < num_percentiles)
    {
        /* Finish the sort, or rescan if we already did */
        if (!osastate->sort_done)
        {
            tuplesort_performsort(osastate->sortstate);
            osastate->sort_done = true;
        }
        else
            tuplesort_rescan(osastate->sortstate);
 
        for (; i < num_percentiles; i++)
        {
            int64       first_row = pct_info[i].first_row;
            int64       second_row = pct_info[i].second_row;
            int         idx = pct_info[i].idx;
 
            /*
             * Advance to first_row, if not already there.  Note that we might
             * already have rownum beyond first_row, in which case first_val
             * is already correct.  (This occurs when interpolating between
             * the same two input rows as for the previous percentile.)
             */
            if (first_row > rownum)
            {
                if (!tuplesort_skiptuples(osastate->sortstate, first_row - rownum - 1, true))
                    elog(ERROR, "missing row in percentile_cont");
 
                if (!tuplesort_getdatum(osastate->sortstate, true, true,
                                        &first_val, &isnull, NULL) || isnull)
                    elog(ERROR, "missing row in percentile_cont");
 
                rownum = first_row;
                /* Always advance second_val to be latest input value */
                second_val = first_val;
            }
            else if (first_row == rownum)
            {
                /*
                 * We are already at the desired row, so we must previously
                 * have read its value into second_val (and perhaps first_val
                 * as well, but this assignment is harmless in that case).
                 */
                first_val = second_val;
            }
 
            /* Fetch second_row if needed */
            if (second_row > rownum)
            {
                if (!tuplesort_getdatum(osastate->sortstate, true, true,
                                        &second_val, &isnull, NULL) || isnull)
                    elog(ERROR, "missing row in percentile_cont");
                rownum++;
            }
            /* We should now certainly be on second_row exactly */
            Assert(second_row == rownum);
 
            /* Compute appropriate result */
            if (second_row > first_row)
                result_datum[idx] = lerpfunc(first_val, second_val,
                                             pct_info[i].proportion);
            else
                result_datum[idx] = first_val;
 
            result_isnull[idx] = false;
        }
    }
 
    /* We make the output array the same shape as the input */
    PG_RETURN_POINTER(construct_md_array(result_datum, result_isnull,
                                         ARR_NDIM(param),
                                         ARR_DIMS(param), ARR_LBOUND(param),
                                         expect_type,
                                         typLen,
                                         typByVal,
                                         typAlign));
}

References AGG_CONTEXT_AGGREGATE, AggCheckCallContext(), ARR_DIMS, ARR_LBOUND, ARR_NDIM, Assert(), construct_empty_array(), construct_md_array(), deconstruct_array_builtin(), elog, ERROR, pct_info::first_row, i, idx(), pct_info::idx, OSAPerGroupState::number_of_rows, palloc(), PG_ARGISNULL, PG_GETARG_ARRAYTYPE_P, PG_GETARG_POINTER, PG_RETURN_NULL, PG_RETURN_POINTER, pct_info::proportion, OSAPerGroupState::qstate, pct_info::second_row, setup_pct_info(), OSAPerGroupState::sort_done, OSAPerQueryState::sortColType, OSAPerGroupState::sortstate, tuplesort_getdatum(), tuplesort_performsort(), tuplesort_rescan(), and tuplesort_skiptuples().

Referenced by percentile_cont_float8_multi_final(), and percentile_cont_interval_multi_final().

percentile_disc_final()

Datum percentile_disc_final

(

PG_FUNCTION_ARGS

)

Definition at line 427 of file orderedsetaggs.c.

{
    OSAPerGroupState *osastate;
    double      percentile;
    Datum       val;
    bool        isnull;
    int64       rownum;
 
    Assert(AggCheckCallContext(fcinfo, NULL) == AGG_CONTEXT_AGGREGATE);
 
    /* Get and check the percentile argument */
    if (PG_ARGISNULL(1))
        PG_RETURN_NULL();
 
    percentile = PG_GETARG_FLOAT8(1);
 
    if (percentile < 0 || percentile > 1 || isnan(percentile))
        ereport(ERROR,
                (errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
                 errmsg("percentile value %g is not between 0 and 1",
                        percentile)));
 
    /* If there were no regular rows, the result is NULL */
    if (PG_ARGISNULL(0))
        PG_RETURN_NULL();
 
    osastate = (OSAPerGroupState *) PG_GETARG_POINTER(0);
 
    /* number_of_rows could be zero if we only saw NULL input values */
    if (osastate->number_of_rows == 0)
        PG_RETURN_NULL();
 
    /* Finish the sort, or rescan if we already did */
    if (!osastate->sort_done)
    {
        tuplesort_performsort(osastate->sortstate);
        osastate->sort_done = true;
    }
    else
        tuplesort_rescan(osastate->sortstate);
 
    /*----------
     * We need the smallest K such that (K/N) >= percentile.
     * N>0, therefore K >= N*percentile, therefore K = ceil(N*percentile).
     * So we skip K-1 rows (if K>0) and return the next row fetched.
     *----------
     */
    rownum = (int64) ceil(percentile * osastate->number_of_rows);
    Assert(rownum <= osastate->number_of_rows);
 
    if (rownum > 1)
    {
        if (!tuplesort_skiptuples(osastate->sortstate, rownum - 1, true))
            elog(ERROR, "missing row in percentile_disc");
    }
 
    if (!tuplesort_getdatum(osastate->sortstate, true, true, &val, &isnull,
                            NULL))
        elog(ERROR, "missing row in percentile_disc");
 
    /* We shouldn't have stored any nulls, but do the right thing anyway */
    if (isnull)
        PG_RETURN_NULL();
    else
        PG_RETURN_DATUM(val);
}

References AGG_CONTEXT_AGGREGATE, AggCheckCallContext(), Assert(), elog, ereport, errcode(), errmsg(), ERROR, OSAPerGroupState::number_of_rows, PG_ARGISNULL, PG_GETARG_FLOAT8, PG_GETARG_POINTER, PG_RETURN_DATUM, PG_RETURN_NULL, OSAPerGroupState::sort_done, OSAPerGroupState::sortstate, tuplesort_getdatum(), tuplesort_performsort(), tuplesort_rescan(), tuplesort_skiptuples(), and val.

percentile_disc_multi_final()

Datum percentile_disc_multi_final

(

PG_FUNCTION_ARGS

)

Definition at line 731 of file orderedsetaggs.c.

{
    OSAPerGroupState *osastate;
    ArrayType  *param;
    Datum      *percentiles_datum;
    bool       *percentiles_null;
    int         num_percentiles;
    struct pct_info *pct_info;
    Datum      *result_datum;
    bool       *result_isnull;
    int64       rownum = 0;
    Datum       val = (Datum) 0;
    bool        isnull = true;
    int         i;
 
    Assert(AggCheckCallContext(fcinfo, NULL) == AGG_CONTEXT_AGGREGATE);
 
    /* If there were no regular rows, the result is NULL */
    if (PG_ARGISNULL(0))
        PG_RETURN_NULL();
 
    osastate = (OSAPerGroupState *) PG_GETARG_POINTER(0);
 
    /* number_of_rows could be zero if we only saw NULL input values */
    if (osastate->number_of_rows == 0)
        PG_RETURN_NULL();
 
    /* Deconstruct the percentile-array input */
    if (PG_ARGISNULL(1))
        PG_RETURN_NULL();
    param = PG_GETARG_ARRAYTYPE_P(1);
 
    deconstruct_array_builtin(param, FLOAT8OID,
                              &percentiles_datum,
                              &percentiles_null,
                              &num_percentiles);
 
    if (num_percentiles == 0)
        PG_RETURN_POINTER(construct_empty_array(osastate->qstate->sortColType));
 
    pct_info = setup_pct_info(num_percentiles,
                              percentiles_datum,
                              percentiles_null,
                              osastate->number_of_rows,
                              false);
 
    result_datum = (Datum *) palloc(num_percentiles * sizeof(Datum));
    result_isnull = (bool *) palloc(num_percentiles * sizeof(bool));
 
    /*
     * Start by dealing with any nulls in the param array - those are sorted
     * to the front on row=0, so set the corresponding result indexes to null
     */
    for (i = 0; i < num_percentiles; i++)
    {
        int         idx = pct_info[i].idx;
 
        if (pct_info[i].first_row > 0)
            break;
 
        result_datum[idx] = (Datum) 0;
        result_isnull[idx] = true;
    }
 
    /*
     * If there's anything left after doing the nulls, then grind the input
     * and extract the needed values
     */
    if (i < num_percentiles)
    {
        /* Finish the sort, or rescan if we already did */
        if (!osastate->sort_done)
        {
            tuplesort_performsort(osastate->sortstate);
            osastate->sort_done = true;
        }
        else
            tuplesort_rescan(osastate->sortstate);
 
        for (; i < num_percentiles; i++)
        {
            int64       target_row = pct_info[i].first_row;
            int         idx = pct_info[i].idx;
 
            /* Advance to target row, if not already there */
            if (target_row > rownum)
            {
                if (!tuplesort_skiptuples(osastate->sortstate, target_row - rownum - 1, true))
                    elog(ERROR, "missing row in percentile_disc");
 
                if (!tuplesort_getdatum(osastate->sortstate, true, true, &val,
                                        &isnull, NULL))
                    elog(ERROR, "missing row in percentile_disc");
 
                rownum = target_row;
            }
 
            result_datum[idx] = val;
            result_isnull[idx] = isnull;
        }
    }
 
    /* We make the output array the same shape as the input */
    PG_RETURN_POINTER(construct_md_array(result_datum, result_isnull,
                                         ARR_NDIM(param),
                                         ARR_DIMS(param),
                                         ARR_LBOUND(param),
                                         osastate->qstate->sortColType,
                                         osastate->qstate->typLen,
                                         osastate->qstate->typByVal,
                                         osastate->qstate->typAlign));
}

References AGG_CONTEXT_AGGREGATE, AggCheckCallContext(), ARR_DIMS, ARR_LBOUND, ARR_NDIM, Assert(), construct_empty_array(), construct_md_array(), deconstruct_array_builtin(), elog, ERROR, pct_info::first_row, i, idx(), pct_info::idx, OSAPerGroupState::number_of_rows, palloc(), PG_ARGISNULL, PG_GETARG_ARRAYTYPE_P, PG_GETARG_POINTER, PG_RETURN_NULL, PG_RETURN_POINTER, OSAPerGroupState::qstate, setup_pct_info(), OSAPerGroupState::sort_done, OSAPerQueryState::sortColType, OSAPerGroupState::sortstate, tuplesort_getdatum(), tuplesort_performsort(), tuplesort_rescan(), tuplesort_skiptuples(), OSAPerQueryState::typAlign, OSAPerQueryState::typByVal, OSAPerQueryState::typLen, and val.

setup_pct_info()

static struct pct_info * setup_pct_info ( int  num_percentiles, Datum *  percentiles_datum, bool *  percentiles_null, int64  rowcount, bool  continuous  )

static

Definition at line 662 of file orderedsetaggs.c.

{
    struct pct_info *pct_info;
    int         i;
 
    pct_info = (struct pct_info *) palloc(num_percentiles * sizeof(struct pct_info));
 
    for (i = 0; i < num_percentiles; i++)
    {
        pct_info[i].idx = i;
 
        if (percentiles_null[i])
        {
            /* dummy entry for any NULL in array */
            pct_info[i].first_row = 0;
            pct_info[i].second_row = 0;
            pct_info[i].proportion = 0;
        }
        else
        {
            double      p = DatumGetFloat8(percentiles_datum[i]);
 
            if (p < 0 || p > 1 || isnan(p))
                ereport(ERROR,
                        (errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
                         errmsg("percentile value %g is not between 0 and 1",
                                p)));
 
            if (continuous)
            {
                pct_info[i].first_row = 1 + floor(p * (rowcount - 1));
                pct_info[i].second_row = 1 + ceil(p * (rowcount - 1));
                pct_info[i].proportion = (p * (rowcount - 1)) - floor(p * (rowcount - 1));
            }
            else
            {
                /*----------
                 * We need the smallest K such that (K/N) >= percentile.
                 * N>0, therefore K >= N*percentile, therefore
                 * K = ceil(N*percentile); but not less than 1.
                 *----------
                 */
                int64       row = (int64) ceil(p * rowcount);
 
                row = Max(1, row);
                pct_info[i].first_row = row;
                pct_info[i].second_row = row;
                pct_info[i].proportion = 0;
            }
        }
    }
 
    /*
     * The parameter array wasn't necessarily in sorted order, but we need to
     * visit the rows in order, so sort by first_row/second_row.
     */
    qsort(pct_info, num_percentiles, sizeof(struct pct_info), pct_info_cmp);
 
    return pct_info;
}

References DatumGetFloat8(), ereport, errcode(), errmsg(), ERROR, pct_info::first_row, i, pct_info::idx, Max, palloc(), pct_info_cmp(), pct_info::proportion, qsort, and pct_info::second_row.

Referenced by percentile_cont_multi_final_common(), and percentile_disc_multi_final().