rewriteManip.c File Reference

#include "postgres.h"
#include "catalog/pg_type.h"
#include "nodes/makefuncs.h"
#include "nodes/nodeFuncs.h"
#include "nodes/pathnodes.h"
#include "nodes/plannodes.h"
#include "parser/parse_coerce.h"
#include "parser/parse_relation.h"
#include "parser/parsetree.h"
#include "rewrite/rewriteManip.h"

Include dependency graph for rewriteManip.c:

Go to the source code of this file.

Data Structures
struct	contain_aggs_of_level_context
struct	locate_agg_of_level_context
struct	locate_windowfunc_context
struct	add_nulling_relids_context
struct	remove_nulling_relids_context
struct	OffsetVarNodes_context
struct	ChangeVarNodes_context
struct	IncrementVarSublevelsUp_context
struct	rangeTableEntry_used_context
struct	map_variable_attnos_context
struct	ReplaceVarsFromTargetList_context

Functions
static bool	contain_aggs_of_level_walker (Node *node, contain_aggs_of_level_context *context)
static bool	locate_agg_of_level_walker (Node *node, locate_agg_of_level_context *context)
static bool	contain_windowfuncs_walker (Node *node, void *context)
static bool	locate_windowfunc_walker (Node *node, locate_windowfunc_context *context)
static bool	checkExprHasSubLink_walker (Node *node, void *context)
static Relids	offset_relid_set (Relids relids, int offset)
static Relids	adjust_relid_set (Relids relids, int oldrelid, int newrelid)
static Node *	add_nulling_relids_mutator (Node *node, add_nulling_relids_context *context)
static Node *	remove_nulling_relids_mutator (Node *node, remove_nulling_relids_context *context)
bool	contain_aggs_of_level (Node *node, int levelsup)
int	locate_agg_of_level (Node *node, int levelsup)
bool	contain_windowfuncs (Node *node)
int	locate_windowfunc (Node *node)
bool	checkExprHasSubLink (Node *node)
static bool	contains_multiexpr_param (Node *node, void *context)
void	CombineRangeTables (List **dst_rtable, List **dst_perminfos, List *src_rtable, List *src_perminfos)
static bool	OffsetVarNodes_walker (Node *node, OffsetVarNodes_context *context)
void	OffsetVarNodes (Node *node, int offset, int sublevels_up)
static bool	ChangeVarNodes_walker (Node *node, ChangeVarNodes_context *context)
void	ChangeVarNodes (Node *node, int rt_index, int new_index, int sublevels_up)
static bool	IncrementVarSublevelsUp_walker (Node *node, IncrementVarSublevelsUp_context *context)
void	IncrementVarSublevelsUp (Node *node, int delta_sublevels_up, int min_sublevels_up)
void	IncrementVarSublevelsUp_rtable (List *rtable, int delta_sublevels_up, int min_sublevels_up)
static bool	rangeTableEntry_used_walker (Node *node, rangeTableEntry_used_context *context)
bool	rangeTableEntry_used (Node *node, int rt_index, int sublevels_up)
Query *	getInsertSelectQuery (Query *parsetree, Query ***subquery_ptr)
void	AddQual (Query *parsetree, Node *qual)
void	AddInvertedQual (Query *parsetree, Node *qual)
Node *	add_nulling_relids (Node *node, const Bitmapset *target_relids, const Bitmapset *added_relids)
Node *	remove_nulling_relids (Node *node, const Bitmapset *removable_relids, const Bitmapset *except_relids)
Node *	replace_rte_variables (Node *node, int target_varno, int sublevels_up, replace_rte_variables_callback callback, void *callback_arg, bool *outer_hasSubLinks)
Node *	replace_rte_variables_mutator (Node *node, replace_rte_variables_context *context)
static Node *	map_variable_attnos_mutator (Node *node, map_variable_attnos_context *context)
Node *	map_variable_attnos (Node *node, int target_varno, int sublevels_up, const AttrMap *attno_map, Oid to_rowtype, bool *found_whole_row)
static Node *	ReplaceVarsFromTargetList_callback (Var *var, replace_rte_variables_context *context)
Node *	ReplaceVarsFromTargetList (Node *node, int target_varno, int sublevels_up, RangeTblEntry *target_rte, List *targetlist, ReplaceVarsNoMatchOption nomatch_option, int nomatch_varno, bool *outer_hasSubLinks)

Function Documentation

add_nulling_relids()

Node* add_nulling_relids	(	Node *	node,
		const Bitmapset *	target_relids,
		const Bitmapset *	added_relids
	)

Definition at line 1139 of file rewriteManip.c.

{
    add_nulling_relids_context context;
 
    context.target_relids = target_relids;
    context.added_relids = added_relids;
    context.sublevels_up = 0;
    return query_or_expression_tree_mutator(node,
                                            add_nulling_relids_mutator,
                                            &context,
                                            0);
}

References add_nulling_relids_mutator(), add_nulling_relids_context::added_relids, query_or_expression_tree_mutator, add_nulling_relids_context::sublevels_up, and add_nulling_relids_context::target_relids.

Referenced by deconstruct_distribute_oj_quals().

add_nulling_relids_mutator()

static Node * add_nulling_relids_mutator ( Node *  node, add_nulling_relids_context *  context  )

static

Definition at line 1155 of file rewriteManip.c.

{
    if (node == NULL)
        return NULL;
    if (IsA(node, Var))
    {
        Var        *var = (Var *) node;
 
        if (var->varlevelsup == context->sublevels_up &&
            bms_is_member(var->varno, context->target_relids))
        {
            Relids      newnullingrels = bms_union(var->varnullingrels,
                                                   context->added_relids);
 
            /* Copy the Var ... */
            var = copyObject(var);
            /* ... and replace the copy's varnullingrels field */
            var->varnullingrels = newnullingrels;
            return (Node *) var;
        }
        /* Otherwise fall through to copy the Var normally */
    }
    else if (IsA(node, PlaceHolderVar))
    {
        PlaceHolderVar *phv = (PlaceHolderVar *) node;
 
        if (phv->phlevelsup == context->sublevels_up &&
            bms_overlap(phv->phrels, context->target_relids))
        {
            Relids      newnullingrels = bms_union(phv->phnullingrels,
                                                   context->added_relids);
 
            /*
             * We don't modify the contents of the PHV's expression, only add
             * to phnullingrels.  This corresponds to assuming that the PHV
             * will be evaluated at the same level as before, then perhaps be
             * nulled as it bubbles up.  Hence, just flat-copy the node ...
             */
            phv = makeNode(PlaceHolderVar);
            memcpy(phv, node, sizeof(PlaceHolderVar));
            /* ... and replace the copy's phnullingrels field */
            phv->phnullingrels = newnullingrels;
            return (Node *) phv;
        }
        /* Otherwise fall through to copy the PlaceHolderVar normally */
    }
    else if (IsA(node, Query))
    {
        /* Recurse into RTE or sublink subquery */
        Query      *newnode;
 
        context->sublevels_up++;
        newnode = query_tree_mutator((Query *) node,
                                     add_nulling_relids_mutator,
                                     (void *) context,
                                     0);
        context->sublevels_up--;
        return (Node *) newnode;
    }
    return expression_tree_mutator(node, add_nulling_relids_mutator,
                                   (void *) context);
}

References add_nulling_relids_context::added_relids, bms_is_member(), bms_overlap(), bms_union(), copyObject, expression_tree_mutator, IsA, makeNode, PlaceHolderVar::phlevelsup, PlaceHolderVar::phnullingrels, query_tree_mutator, add_nulling_relids_context::sublevels_up, add_nulling_relids_context::target_relids, Var::varlevelsup, and Var::varno.

Referenced by add_nulling_relids().

AddInvertedQual()

void AddInvertedQual	(	Query *	parsetree,
		Node *	qual
	)

Definition at line 1116 of file rewriteManip.c.

{
    BooleanTest *invqual;
 
    if (qual == NULL)
        return;
 
    /* Need not copy input qual, because AddQual will... */
    invqual = makeNode(BooleanTest);
    invqual->arg = (Expr *) qual;
    invqual->booltesttype = IS_NOT_TRUE;
    invqual->location = -1;
 
    AddQual(parsetree, (Node *) invqual);
}

References AddQual(), BooleanTest::arg, BooleanTest::booltesttype, IS_NOT_TRUE, BooleanTest::location, and makeNode.

Referenced by CopyAndAddInvertedQual().

AddQual()

void AddQual	(	Query *	parsetree,
		Node *	qual
	)

Definition at line 1048 of file rewriteManip.c.

{
    Node       *copy;
 
    if (qual == NULL)
        return;
 
    if (parsetree->commandType == CMD_UTILITY)
    {
        /*
         * There's noplace to put the qual on a utility statement.
         *
         * If it's a NOTIFY, silently ignore the qual; this means that the
         * NOTIFY will execute, whether or not there are any qualifying rows.
         * While clearly wrong, this is much more useful than refusing to
         * execute the rule at all, and extra NOTIFY events are harmless for
         * typical uses of NOTIFY.
         *
         * If it isn't a NOTIFY, error out, since unconditional execution of
         * other utility stmts is unlikely to be wanted.  (This case is not
         * currently allowed anyway, but keep the test for safety.)
         */
        if (parsetree->utilityStmt && IsA(parsetree->utilityStmt, NotifyStmt))
            return;
        else
            ereport(ERROR,
                    (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
                     errmsg("conditional utility statements are not implemented")));
    }
 
    if (parsetree->setOperations != NULL)
    {
        /*
         * There's noplace to put the qual on a setop statement, either. (This
         * could be fixed, but right now the planner simply ignores any qual
         * condition on a setop query.)
         */
        ereport(ERROR,
                (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
                 errmsg("conditional UNION/INTERSECT/EXCEPT statements are not implemented")));
    }
 
    /* INTERSECT wants the original, but we need to copy - Jan */
    copy = copyObject(qual);
 
    parsetree->jointree->quals = make_and_qual(parsetree->jointree->quals,
                                               copy);
 
    /*
     * We had better not have stuck an aggregate into the WHERE clause.
     */
    Assert(!contain_aggs_of_level(copy, 0));
 
    /*
     * Make sure query is marked correctly if added qual has sublinks. Need
     * not search qual when query is already marked.
     */
    if (!parsetree->hasSubLinks)
        parsetree->hasSubLinks = checkExprHasSubLink(copy);
}

References Assert(), checkExprHasSubLink(), CMD_UTILITY, Query::commandType, contain_aggs_of_level(), copyObject, ereport, errcode(), errmsg(), ERROR, IsA, Query::jointree, make_and_qual(), FromExpr::quals, Query::setOperations, and Query::utilityStmt.

Referenced by AddInvertedQual(), rewriteRuleAction(), and rewriteTargetView().

adjust_relid_set()

static Relids adjust_relid_set ( Relids  relids, int  oldrelid, int  newrelid  )

static

Definition at line 729 of file rewriteManip.c.

{
    if (!IS_SPECIAL_VARNO(oldrelid) && bms_is_member(oldrelid, relids))
    {
        /* Ensure we have a modifiable copy */
        relids = bms_copy(relids);
        /* Remove old, add new */
        relids = bms_del_member(relids, oldrelid);
        relids = bms_add_member(relids, newrelid);
    }
    return relids;
}

References bms_add_member(), bms_copy(), bms_del_member(), bms_is_member(), and IS_SPECIAL_VARNO.

Referenced by ChangeVarNodes_walker().

ChangeVarNodes()

void ChangeVarNodes	(	Node *	node,
		int	rt_index,
		int	new_index,
		int	sublevels_up
	)

Definition at line 670 of file rewriteManip.c.

{
    ChangeVarNodes_context context;
 
    context.rt_index = rt_index;
    context.new_index = new_index;
    context.sublevels_up = sublevels_up;
 
    /*
     * Must be prepared to start with a Query or a bare expression tree; if
     * it's a Query, go straight to query_tree_walker to make sure that
     * sublevels_up doesn't get incremented prematurely.
     */
    if (node && IsA(node, Query))
    {
        Query      *qry = (Query *) node;
 
        /*
         * If we are starting at a Query, and sublevels_up is zero, then we
         * must also fix rangetable indexes in the Query itself --- namely
         * resultRelation and rowMarks entries.  sublevels_up cannot be zero
         * when recursing into a subquery, so there's no need to have the same
         * logic inside ChangeVarNodes_walker.
         */
        if (sublevels_up == 0)
        {
            ListCell   *l;
 
            if (qry->resultRelation == rt_index)
                qry->resultRelation = new_index;
 
            /* this is unlikely to ever be used, but ... */
            if (qry->onConflict && qry->onConflict->exclRelIndex == rt_index)
                qry->onConflict->exclRelIndex = new_index;
 
            foreach(l, qry->rowMarks)
            {
                RowMarkClause *rc = (RowMarkClause *) lfirst(l);
 
                if (rc->rti == rt_index)
                    rc->rti = new_index;
            }
        }
        query_tree_walker(qry, ChangeVarNodes_walker,
                          (void *) &context, 0);
    }
    else
        ChangeVarNodes_walker(node, &context);
}

References ChangeVarNodes_walker(), OnConflictExpr::exclRelIndex, IsA, lfirst, ChangeVarNodes_context::new_index, Query::onConflict, query_tree_walker, Query::rowMarks, ChangeVarNodes_context::rt_index, RowMarkClause::rti, and ChangeVarNodes_context::sublevels_up.

Referenced by add_security_quals(), add_with_check_options(), ApplyRetrieveRule(), CopyAndAddInvertedQual(), get_relation_constraints(), get_relation_info(), get_relation_statistics(), rewriteRuleAction(), rewriteTargetView(), set_baserel_partition_constraint(), set_baserel_partition_key_exprs(), and TriggerEnabled().

ChangeVarNodes_walker()

static bool ChangeVarNodes_walker ( Node *  node, ChangeVarNodes_context *  context  )

static

Definition at line 560 of file rewriteManip.c.

{
    if (node == NULL)
        return false;
    if (IsA(node, Var))
    {
        Var        *var = (Var *) node;
 
        if (var->varlevelsup == context->sublevels_up)
        {
            if (var->varno == context->rt_index)
                var->varno = context->new_index;
            var->varnullingrels = adjust_relid_set(var->varnullingrels,
                                                   context->rt_index,
                                                   context->new_index);
            if (var->varnosyn == context->rt_index)
                var->varnosyn = context->new_index;
        }
        return false;
    }
    if (IsA(node, CurrentOfExpr))
    {
        CurrentOfExpr *cexpr = (CurrentOfExpr *) node;
 
        if (context->sublevels_up == 0 &&
            cexpr->cvarno == context->rt_index)
            cexpr->cvarno = context->new_index;
        return false;
    }
    if (IsA(node, RangeTblRef))
    {
        RangeTblRef *rtr = (RangeTblRef *) node;
 
        if (context->sublevels_up == 0 &&
            rtr->rtindex == context->rt_index)
            rtr->rtindex = context->new_index;
        /* the subquery itself is visited separately */
        return false;
    }
    if (IsA(node, JoinExpr))
    {
        JoinExpr   *j = (JoinExpr *) node;
 
        if (context->sublevels_up == 0 &&
            j->rtindex == context->rt_index)
            j->rtindex = context->new_index;
        /* fall through to examine children */
    }
    if (IsA(node, PlaceHolderVar))
    {
        PlaceHolderVar *phv = (PlaceHolderVar *) node;
 
        if (phv->phlevelsup == context->sublevels_up)
        {
            phv->phrels = adjust_relid_set(phv->phrels,
                                           context->rt_index,
                                           context->new_index);
            phv->phnullingrels = adjust_relid_set(phv->phnullingrels,
                                                  context->rt_index,
                                                  context->new_index);
        }
        /* fall through to examine children */
    }
    if (IsA(node, PlanRowMark))
    {
        PlanRowMark *rowmark = (PlanRowMark *) node;
 
        if (context->sublevels_up == 0)
        {
            if (rowmark->rti == context->rt_index)
                rowmark->rti = context->new_index;
            if (rowmark->prti == context->rt_index)
                rowmark->prti = context->new_index;
        }
        return false;
    }
    if (IsA(node, AppendRelInfo))
    {
        AppendRelInfo *appinfo = (AppendRelInfo *) node;
 
        if (context->sublevels_up == 0)
        {
            if (appinfo->parent_relid == context->rt_index)
                appinfo->parent_relid = context->new_index;
            if (appinfo->child_relid == context->rt_index)
                appinfo->child_relid = context->new_index;
        }
        /* fall through to examine children */
    }
    /* Shouldn't need to handle other planner auxiliary nodes here */
    Assert(!IsA(node, SpecialJoinInfo));
    Assert(!IsA(node, PlaceHolderInfo));
    Assert(!IsA(node, MinMaxAggInfo));
 
    if (IsA(node, Query))
    {
        /* Recurse into subselects */
        bool        result;
 
        context->sublevels_up++;
        result = query_tree_walker((Query *) node, ChangeVarNodes_walker,
                                   (void *) context, 0);
        context->sublevels_up--;
        return result;
    }
    return expression_tree_walker(node, ChangeVarNodes_walker,
                                  (void *) context);
}

References adjust_relid_set(), Assert(), AppendRelInfo::child_relid, CurrentOfExpr::cvarno, expression_tree_walker, IsA, j, ChangeVarNodes_context::new_index, AppendRelInfo::parent_relid, PlaceHolderVar::phlevelsup, PlaceHolderVar::phnullingrels, PlanRowMark::prti, query_tree_walker, ChangeVarNodes_context::rt_index, PlanRowMark::rti, RangeTblRef::rtindex, ChangeVarNodes_context::sublevels_up, Var::varlevelsup, and Var::varno.

Referenced by ChangeVarNodes().

checkExprHasSubLink()

bool checkExprHasSubLink

(

Node *

node

)

Definition at line 295 of file rewriteManip.c.

{
    /*
     * If a Query is passed, examine it --- but we should not recurse into
     * sub-Queries that are in its rangetable or CTE list.
     */
    return query_or_expression_tree_walker(node,
                                           checkExprHasSubLink_walker,
                                           NULL,
                                           QTW_IGNORE_RC_SUBQUERIES);
}

References checkExprHasSubLink_walker(), QTW_IGNORE_RC_SUBQUERIES, and query_or_expression_tree_walker.

Referenced by AddQual(), flatten_join_alias_vars_mutator(), RelationBuildRowSecurity(), replace_rte_variables_mutator(), rewriteRuleAction(), and rewriteTargetView().

checkExprHasSubLink_walker()

static bool checkExprHasSubLink_walker ( Node *  node, void *  context  )

static

Definition at line 308 of file rewriteManip.c.

{
    if (node == NULL)
        return false;
    if (IsA(node, SubLink))
        return true;            /* abort the tree traversal and return true */
    return expression_tree_walker(node, checkExprHasSubLink_walker, context);
}

References expression_tree_walker, and IsA.

Referenced by checkExprHasSubLink().

CombineRangeTables()

void CombineRangeTables	(	List **	dst_rtable,
		List **	dst_perminfos,
		List *	src_rtable,
		List *	src_perminfos
	)

Definition at line 350 of file rewriteManip.c.

{
    ListCell   *l;
    int         offset = list_length(*dst_perminfos);
 
    if (offset > 0)
    {
        foreach(l, src_rtable)
        {
            RangeTblEntry *rte = lfirst_node(RangeTblEntry, l);
 
            if (rte->perminfoindex > 0)
                rte->perminfoindex += offset;
        }
    }
 
    *dst_perminfos = list_concat(*dst_perminfos, src_perminfos);
    *dst_rtable = list_concat(*dst_rtable, src_rtable);
}

References lfirst_node, list_concat(), list_length(), and RangeTblEntry::perminfoindex.

Referenced by convert_EXISTS_sublink_to_join(), pull_up_simple_subquery(), pull_up_simple_union_all(), and rewriteRuleAction().

contain_aggs_of_level()

bool contain_aggs_of_level	(	Node *	node,
		int	levelsup
	)

Definition at line 85 of file rewriteManip.c.

{
    contain_aggs_of_level_context context;
 
    context.sublevels_up = levelsup;
 
    /*
     * Must be prepared to start with a Query or a bare expression tree; if
     * it's a Query, we don't want to increment sublevels_up.
     */
    return query_or_expression_tree_walker(node,
                                           contain_aggs_of_level_walker,
                                           (void *) &context,
                                           0);
}

References contain_aggs_of_level_walker(), query_or_expression_tree_walker, and contain_aggs_of_level_context::sublevels_up.

Referenced by AddQual(), checkTargetlistEntrySQL92(), and convert_EXISTS_to_ANY().

contain_aggs_of_level_walker()

static bool contain_aggs_of_level_walker ( Node *  node, contain_aggs_of_level_context *  context  )

static

Definition at line 102 of file rewriteManip.c.

{
    if (node == NULL)
        return false;
    if (IsA(node, Aggref))
    {
        if (((Aggref *) node)->agglevelsup == context->sublevels_up)
            return true;        /* abort the tree traversal and return true */
        /* else fall through to examine argument */
    }
    if (IsA(node, GroupingFunc))
    {
        if (((GroupingFunc *) node)->agglevelsup == context->sublevels_up)
            return true;
        /* else fall through to examine argument */
    }
    if (IsA(node, Query))
    {
        /* Recurse into subselects */
        bool        result;
 
        context->sublevels_up++;
        result = query_tree_walker((Query *) node,
                                   contain_aggs_of_level_walker,
                                   (void *) context, 0);
        context->sublevels_up--;
        return result;
    }
    return expression_tree_walker(node, contain_aggs_of_level_walker,
                                  (void *) context);
}

References expression_tree_walker, IsA, query_tree_walker, and contain_aggs_of_level_context::sublevels_up.

Referenced by contain_aggs_of_level().

contain_windowfuncs()

bool contain_windowfuncs

(

Node *

node

)

Definition at line 215 of file rewriteManip.c.

{
    /*
     * Must be prepared to start with a Query or a bare expression tree; if
     * it's a Query, we don't want to increment sublevels_up.
     */
    return query_or_expression_tree_walker(node,
                                           contain_windowfuncs_walker,
                                           NULL,
                                           0);
}

References contain_windowfuncs_walker(), and query_or_expression_tree_walker.

Referenced by checkTargetlistEntrySQL92(), contain_window_function(), and transformWindowFuncCall().

contain_windowfuncs_walker()

static bool contain_windowfuncs_walker ( Node *  node, void *  context  )

static

Definition at line 228 of file rewriteManip.c.

{
    if (node == NULL)
        return false;
    if (IsA(node, WindowFunc))
        return true;            /* abort the tree traversal and return true */
    /* Mustn't recurse into subselects */
    return expression_tree_walker(node, contain_windowfuncs_walker,
                                  (void *) context);
}

References expression_tree_walker, and IsA.

Referenced by contain_windowfuncs().

contains_multiexpr_param()

static bool contains_multiexpr_param ( Node *  node, void *  context  )

static

Definition at line 324 of file rewriteManip.c.

{
    if (node == NULL)
        return false;
    if (IsA(node, Param))
    {
        if (((Param *) node)->paramkind == PARAM_MULTIEXPR)
            return true;        /* abort the tree traversal and return true */
        return false;
    }
    return expression_tree_walker(node, contains_multiexpr_param, context);
}

References expression_tree_walker, IsA, and PARAM_MULTIEXPR.

Referenced by ReplaceVarsFromTargetList_callback().

getInsertSelectQuery()

Query* getInsertSelectQuery	(	Query *	parsetree,
		Query ***	subquery_ptr
	)

Definition at line 990 of file rewriteManip.c.

{
    Query      *selectquery;
    RangeTblEntry *selectrte;
    RangeTblRef *rtr;
 
    if (subquery_ptr)
        *subquery_ptr = NULL;
 
    if (parsetree == NULL)
        return parsetree;
    if (parsetree->commandType != CMD_INSERT)
        return parsetree;
 
    /*
     * Currently, this is ONLY applied to rule-action queries, and so we
     * expect to find the OLD and NEW placeholder entries in the given query.
     * If they're not there, it must be an INSERT/SELECT in which they've been
     * pushed down to the SELECT.
     */
    if (list_length(parsetree->rtable) >= 2 &&
        strcmp(rt_fetch(PRS2_OLD_VARNO, parsetree->rtable)->eref->aliasname,
               "old") == 0 &&
        strcmp(rt_fetch(PRS2_NEW_VARNO, parsetree->rtable)->eref->aliasname,
               "new") == 0)
        return parsetree;
    Assert(parsetree->jointree && IsA(parsetree->jointree, FromExpr));
    if (list_length(parsetree->jointree->fromlist) != 1)
        elog(ERROR, "expected to find SELECT subquery");
    rtr = (RangeTblRef *) linitial(parsetree->jointree->fromlist);
    if (!IsA(rtr, RangeTblRef))
        elog(ERROR, "expected to find SELECT subquery");
    selectrte = rt_fetch(rtr->rtindex, parsetree->rtable);
    if (!(selectrte->rtekind == RTE_SUBQUERY &&
          selectrte->subquery &&
          IsA(selectrte->subquery, Query) &&
          selectrte->subquery->commandType == CMD_SELECT))
        elog(ERROR, "expected to find SELECT subquery");
    selectquery = selectrte->subquery;
    if (list_length(selectquery->rtable) >= 2 &&
        strcmp(rt_fetch(PRS2_OLD_VARNO, selectquery->rtable)->eref->aliasname,
               "old") == 0 &&
        strcmp(rt_fetch(PRS2_NEW_VARNO, selectquery->rtable)->eref->aliasname,
               "new") == 0)
    {
        if (subquery_ptr)
            *subquery_ptr = &(selectrte->subquery);
        return selectquery;
    }
    elog(ERROR, "could not find rule placeholders");
    return NULL;                /* not reached */
}

References Assert(), CMD_INSERT, CMD_SELECT, Query::commandType, elog(), ERROR, FromExpr::fromlist, IsA, Query::jointree, linitial, list_length(), PRS2_NEW_VARNO, PRS2_OLD_VARNO, rt_fetch, Query::rtable, RTE_SUBQUERY, RangeTblEntry::rtekind, RangeTblRef::rtindex, and RangeTblEntry::subquery.

Referenced by DefineQueryRewrite(), InsertRule(), make_ruledef(), rewriteRuleAction(), and transformRuleStmt().

IncrementVarSublevelsUp()

void IncrementVarSublevelsUp	(	Node *	node,
		int	delta_sublevels_up,
		int	min_sublevels_up
	)

Definition at line 841 of file rewriteManip.c.

{
    IncrementVarSublevelsUp_context context;
 
    context.delta_sublevels_up = delta_sublevels_up;
    context.min_sublevels_up = min_sublevels_up;
 
    /*
     * Must be prepared to start with a Query or a bare expression tree; if
     * it's a Query, we don't want to increment sublevels_up.
     */
    query_or_expression_tree_walker(node,
                                    IncrementVarSublevelsUp_walker,
                                    (void *) &context,
                                    QTW_EXAMINE_RTES_BEFORE);
}

References IncrementVarSublevelsUp_context::delta_sublevels_up, IncrementVarSublevelsUp_walker(), IncrementVarSublevelsUp_context::min_sublevels_up, QTW_EXAMINE_RTES_BEFORE, and query_or_expression_tree_walker.

Referenced by assign_param_for_placeholdervar(), build_minmax_path(), convert_EXISTS_sublink_to_join(), convert_EXISTS_to_ANY(), extract_lateral_references(), flatten_join_alias_vars_mutator(), inline_cte_walker(), pull_up_simple_subquery(), pullup_replace_vars_callback(), replace_outer_agg(), replace_outer_grouping(), ReplaceVarsFromTargetList_callback(), rewriteSearchAndCycle(), and substitute_actual_srf_parameters_mutator().

IncrementVarSublevelsUp_rtable()

void IncrementVarSublevelsUp_rtable	(	List *	rtable,
		int	delta_sublevels_up,
		int	min_sublevels_up
	)

Definition at line 864 of file rewriteManip.c.

{
    IncrementVarSublevelsUp_context context;
 
    context.delta_sublevels_up = delta_sublevels_up;
    context.min_sublevels_up = min_sublevels_up;
 
    range_table_walker(rtable,
                       IncrementVarSublevelsUp_walker,
                       (void *) &context,
                       QTW_EXAMINE_RTES_BEFORE);
}

References IncrementVarSublevelsUp_context::delta_sublevels_up, IncrementVarSublevelsUp_walker(), IncrementVarSublevelsUp_context::min_sublevels_up, QTW_EXAMINE_RTES_BEFORE, and range_table_walker.

Referenced by pull_up_simple_union_all().

IncrementVarSublevelsUp_walker()

static bool IncrementVarSublevelsUp_walker ( Node *  node, IncrementVarSublevelsUp_context *  context  )

static

Definition at line 768 of file rewriteManip.c.

{
    if (node == NULL)
        return false;
    if (IsA(node, Var))
    {
        Var        *var = (Var *) node;
 
        if (var->varlevelsup >= context->min_sublevels_up)
            var->varlevelsup += context->delta_sublevels_up;
        return false;           /* done here */
    }
    if (IsA(node, CurrentOfExpr))
    {
        /* this should not happen */
        if (context->min_sublevels_up == 0)
            elog(ERROR, "cannot push down CurrentOfExpr");
        return false;
    }
    if (IsA(node, Aggref))
    {
        Aggref     *agg = (Aggref *) node;
 
        if (agg->agglevelsup >= context->min_sublevels_up)
            agg->agglevelsup += context->delta_sublevels_up;
        /* fall through to recurse into argument */
    }
    if (IsA(node, GroupingFunc))
    {
        GroupingFunc *grp = (GroupingFunc *) node;
 
        if (grp->agglevelsup >= context->min_sublevels_up)
            grp->agglevelsup += context->delta_sublevels_up;
        /* fall through to recurse into argument */
    }
    if (IsA(node, PlaceHolderVar))
    {
        PlaceHolderVar *phv = (PlaceHolderVar *) node;
 
        if (phv->phlevelsup >= context->min_sublevels_up)
            phv->phlevelsup += context->delta_sublevels_up;
        /* fall through to recurse into argument */
    }
    if (IsA(node, RangeTblEntry))
    {
        RangeTblEntry *rte = (RangeTblEntry *) node;
 
        if (rte->rtekind == RTE_CTE)
        {
            if (rte->ctelevelsup >= context->min_sublevels_up)
                rte->ctelevelsup += context->delta_sublevels_up;
        }
        return false;           /* allow range_table_walker to continue */
    }
    if (IsA(node, Query))
    {
        /* Recurse into subselects */
        bool        result;
 
        context->min_sublevels_up++;
        result = query_tree_walker((Query *) node,
                                   IncrementVarSublevelsUp_walker,
                                   (void *) context,
                                   QTW_EXAMINE_RTES_BEFORE);
        context->min_sublevels_up--;
        return result;
    }
    return expression_tree_walker(node, IncrementVarSublevelsUp_walker,
                                  (void *) context);
}

References GroupingFunc::agglevelsup, RangeTblEntry::ctelevelsup, IncrementVarSublevelsUp_context::delta_sublevels_up, elog(), ERROR, expression_tree_walker, IsA, IncrementVarSublevelsUp_context::min_sublevels_up, PlaceHolderVar::phlevelsup, QTW_EXAMINE_RTES_BEFORE, query_tree_walker, RTE_CTE, RangeTblEntry::rtekind, and Var::varlevelsup.

Referenced by IncrementVarSublevelsUp(), and IncrementVarSublevelsUp_rtable().

locate_agg_of_level()

int locate_agg_of_level	(	Node *	node,
		int	levelsup
	)

Definition at line 149 of file rewriteManip.c.

{
    locate_agg_of_level_context context;
 
    context.agg_location = -1;  /* in case we find nothing */
    context.sublevels_up = levelsup;
 
    /*
     * Must be prepared to start with a Query or a bare expression tree; if
     * it's a Query, we don't want to increment sublevels_up.
     */
    (void) query_or_expression_tree_walker(node,
                                           locate_agg_of_level_walker,
                                           (void *) &context,
                                           0);
 
    return context.agg_location;
}

References locate_agg_of_level_context::agg_location, locate_agg_of_level_walker(), query_or_expression_tree_walker, and locate_agg_of_level_context::sublevels_up.

Referenced by check_agg_arguments(), checkTargetlistEntrySQL92(), and parseCheckAggregates().

locate_agg_of_level_walker()

static bool locate_agg_of_level_walker ( Node *  node, locate_agg_of_level_context *  context  )

static

Definition at line 169 of file rewriteManip.c.

{
    if (node == NULL)
        return false;
    if (IsA(node, Aggref))
    {
        if (((Aggref *) node)->agglevelsup == context->sublevels_up &&
            ((Aggref *) node)->location >= 0)
        {
            context->agg_location = ((Aggref *) node)->location;
            return true;        /* abort the tree traversal and return true */
        }
        /* else fall through to examine argument */
    }
    if (IsA(node, GroupingFunc))
    {
        if (((GroupingFunc *) node)->agglevelsup == context->sublevels_up &&
            ((GroupingFunc *) node)->location >= 0)
        {
            context->agg_location = ((GroupingFunc *) node)->location;
            return true;        /* abort the tree traversal and return true */
        }
    }
    if (IsA(node, Query))
    {
        /* Recurse into subselects */
        bool        result;
 
        context->sublevels_up++;
        result = query_tree_walker((Query *) node,
                                   locate_agg_of_level_walker,
                                   (void *) context, 0);
        context->sublevels_up--;
        return result;
    }
    return expression_tree_walker(node, locate_agg_of_level_walker,
                                  (void *) context);
}

References locate_agg_of_level_context::agg_location, expression_tree_walker, IsA, query_tree_walker, and locate_agg_of_level_context::sublevels_up.

Referenced by locate_agg_of_level().

locate_windowfunc()

int locate_windowfunc

(

Node *

node

)

Definition at line 253 of file rewriteManip.c.

{
    locate_windowfunc_context context;
 
    context.win_location = -1;  /* in case we find nothing */
 
    /*
     * Must be prepared to start with a Query or a bare expression tree; if
     * it's a Query, we don't want to increment sublevels_up.
     */
    (void) query_or_expression_tree_walker(node,
                                           locate_windowfunc_walker,
                                           (void *) &context,
                                           0);
 
    return context.win_location;
}

References locate_windowfunc_walker(), query_or_expression_tree_walker, and locate_windowfunc_context::win_location.

Referenced by checkTargetlistEntrySQL92(), and transformWindowFuncCall().

locate_windowfunc_walker()

static bool locate_windowfunc_walker ( Node *  node, locate_windowfunc_context *  context  )

static

Definition at line 272 of file rewriteManip.c.

{
    if (node == NULL)
        return false;
    if (IsA(node, WindowFunc))
    {
        if (((WindowFunc *) node)->location >= 0)
        {
            context->win_location = ((WindowFunc *) node)->location;
            return true;        /* abort the tree traversal and return true */
        }
        /* else fall through to examine argument */
    }
    /* Mustn't recurse into subselects */
    return expression_tree_walker(node, locate_windowfunc_walker,
                                  (void *) context);
}

References expression_tree_walker, IsA, and locate_windowfunc_context::win_location.

Referenced by locate_windowfunc().

map_variable_attnos()

Node* map_variable_attnos	(	Node *	node,
		int	target_varno,
		int	sublevels_up,
		const AttrMap *	attno_map,
		Oid	to_rowtype,
		bool *	found_whole_row
	)

Definition at line 1603 of file rewriteManip.c.

{
    map_variable_attnos_context context;
 
    context.target_varno = target_varno;
    context.sublevels_up = sublevels_up;
    context.attno_map = attno_map;
    context.to_rowtype = to_rowtype;
    context.found_whole_row = found_whole_row;
 
    *found_whole_row = false;
 
    /*
     * Must be prepared to start with a Query or a bare expression tree; if
     * it's a Query, we don't want to increment sublevels_up.
     */
    return query_or_expression_tree_mutator(node,
                                            map_variable_attnos_mutator,
                                            (void *) &context,
                                            0);
}

References map_variable_attnos_context::attno_map, map_variable_attnos_context::found_whole_row, map_variable_attnos_mutator(), query_or_expression_tree_mutator, map_variable_attnos_context::sublevels_up, map_variable_attnos_context::target_varno, and map_variable_attnos_context::to_rowtype.

Referenced by ATPrepAlterColumnType(), CompareIndexInfo(), DefineIndex(), ExecInitPartitionInfo(), expandTableLikeClause(), generateClonedIndexStmt(), map_partition_varattnos(), and MergeAttributes().

map_variable_attnos_mutator()

static Node* map_variable_attnos_mutator ( Node *  node, map_variable_attnos_context *  context  )

static

Definition at line 1480 of file rewriteManip.c.

{
    if (node == NULL)
        return NULL;
    if (IsA(node, Var))
    {
        Var        *var = (Var *) node;
 
        if (var->varno == context->target_varno &&
            var->varlevelsup == context->sublevels_up)
        {
            /* Found a matching variable, make the substitution */
            Var        *newvar = (Var *) palloc(sizeof(Var));
            int         attno = var->varattno;
 
            *newvar = *var;     /* initially copy all fields of the Var */
 
            if (attno > 0)
            {
                /* user-defined column, replace attno */
                if (attno > context->attno_map->maplen ||
                    context->attno_map->attnums[attno - 1] == 0)
                    elog(ERROR, "unexpected varattno %d in expression to be mapped",
                         attno);
                newvar->varattno = context->attno_map->attnums[attno - 1];
                /* If the syntactic referent is same RTE, fix it too */
                if (newvar->varnosyn == context->target_varno)
                    newvar->varattnosyn = newvar->varattno;
            }
            else if (attno == 0)
            {
                /* whole-row variable, warn caller */
                *(context->found_whole_row) = true;
 
                /* If the caller expects us to convert the Var, do so. */
                if (OidIsValid(context->to_rowtype) &&
                    context->to_rowtype != var->vartype)
                {
                    ConvertRowtypeExpr *r;
 
                    /* This certainly won't work for a RECORD variable. */
                    Assert(var->vartype != RECORDOID);
 
                    /* Var itself is changed to the requested type. */
                    newvar->vartype = context->to_rowtype;
 
                    /*
                     * Add a conversion node on top to convert back to the
                     * original type expected by the expression.
                     */
                    r = makeNode(ConvertRowtypeExpr);
                    r->arg = (Expr *) newvar;
                    r->resulttype = var->vartype;
                    r->convertformat = COERCE_IMPLICIT_CAST;
                    r->location = -1;
 
                    return (Node *) r;
                }
            }
            return (Node *) newvar;
        }
        /* otherwise fall through to copy the var normally */
    }
    else if (IsA(node, ConvertRowtypeExpr))
    {
        ConvertRowtypeExpr *r = (ConvertRowtypeExpr *) node;
        Var        *var = (Var *) r->arg;
 
        /*
         * If this is coercing a whole-row Var that we need to convert, then
         * just convert the Var without adding an extra ConvertRowtypeExpr.
         * Effectively we're simplifying var::parenttype::grandparenttype into
         * just var::grandparenttype.  This avoids building stacks of CREs if
         * this function is applied repeatedly.
         */
        if (IsA(var, Var) &&
            var->varno == context->target_varno &&
            var->varlevelsup == context->sublevels_up &&
            var->varattno == 0 &&
            OidIsValid(context->to_rowtype) &&
            context->to_rowtype != var->vartype)
        {
            ConvertRowtypeExpr *newnode;
            Var        *newvar = (Var *) palloc(sizeof(Var));
 
            /* whole-row variable, warn caller */
            *(context->found_whole_row) = true;
 
            *newvar = *var;     /* initially copy all fields of the Var */
 
            /* This certainly won't work for a RECORD variable. */
            Assert(var->vartype != RECORDOID);
 
            /* Var itself is changed to the requested type. */
            newvar->vartype = context->to_rowtype;
 
            newnode = (ConvertRowtypeExpr *) palloc(sizeof(ConvertRowtypeExpr));
            *newnode = *r;      /* initially copy all fields of the CRE */
            newnode->arg = (Expr *) newvar;
 
            return (Node *) newnode;
        }
        /* otherwise fall through to process the expression normally */
    }
    else if (IsA(node, Query))
    {
        /* Recurse into RTE subquery or not-yet-planned sublink subquery */
        Query      *newnode;
 
        context->sublevels_up++;
        newnode = query_tree_mutator((Query *) node,
                                     map_variable_attnos_mutator,
                                     (void *) context,
                                     0);
        context->sublevels_up--;
        return (Node *) newnode;
    }
    return expression_tree_mutator(node, map_variable_attnos_mutator,
                                   (void *) context);
}

References ConvertRowtypeExpr::arg, Assert(), map_variable_attnos_context::attno_map, AttrMap::attnums, COERCE_IMPLICIT_CAST, elog(), ERROR, expression_tree_mutator, map_variable_attnos_context::found_whole_row, if(), IsA, ConvertRowtypeExpr::location, makeNode, AttrMap::maplen, OidIsValid, palloc(), query_tree_mutator, ConvertRowtypeExpr::resulttype, map_variable_attnos_context::sublevels_up, map_variable_attnos_context::target_varno, map_variable_attnos_context::to_rowtype, Var::varattno, Var::varlevelsup, and Var::varno.

Referenced by map_variable_attnos().

offset_relid_set()

static Relids offset_relid_set ( Relids  relids, int  offset  )

static

Definition at line 528 of file rewriteManip.c.

{
    Relids      result = NULL;
    int         rtindex;
 
    rtindex = -1;
    while ((rtindex = bms_next_member(relids, rtindex)) >= 0)
        result = bms_add_member(result, rtindex + offset);
    return result;
}

References bms_add_member(), and bms_next_member().

Referenced by OffsetVarNodes_walker().

OffsetVarNodes()

void OffsetVarNodes	(	Node *	node,
		int	offset,
		int	sublevels_up
	)

Definition at line 480 of file rewriteManip.c.

{
    OffsetVarNodes_context context;
 
    context.offset = offset;
    context.sublevels_up = sublevels_up;
 
    /*
     * Must be prepared to start with a Query or a bare expression tree; if
     * it's a Query, go straight to query_tree_walker to make sure that
     * sublevels_up doesn't get incremented prematurely.
     */
    if (node && IsA(node, Query))
    {
        Query      *qry = (Query *) node;
 
        /*
         * If we are starting at a Query, and sublevels_up is zero, then we
         * must also fix rangetable indexes in the Query itself --- namely
         * resultRelation, exclRelIndex and rowMarks entries.  sublevels_up
         * cannot be zero when recursing into a subquery, so there's no need
         * to have the same logic inside OffsetVarNodes_walker.
         */
        if (sublevels_up == 0)
        {
            ListCell   *l;
 
            if (qry->resultRelation)
                qry->resultRelation += offset;
 
            if (qry->onConflict && qry->onConflict->exclRelIndex)
                qry->onConflict->exclRelIndex += offset;
 
            foreach(l, qry->rowMarks)
            {
                RowMarkClause *rc = (RowMarkClause *) lfirst(l);
 
                rc->rti += offset;
            }
        }
        query_tree_walker(qry, OffsetVarNodes_walker,
                          (void *) &context, 0);
    }
    else
        OffsetVarNodes_walker(node, &context);
}

References OnConflictExpr::exclRelIndex, IsA, lfirst, OffsetVarNodes_context::offset, OffsetVarNodes_walker(), Query::onConflict, query_tree_walker, Query::rowMarks, RowMarkClause::rti, and OffsetVarNodes_context::sublevels_up.

Referenced by convert_EXISTS_sublink_to_join(), pull_up_simple_subquery(), and rewriteRuleAction().

OffsetVarNodes_walker()

static bool OffsetVarNodes_walker ( Node *  node, OffsetVarNodes_context *  context  )

static

Definition at line 391 of file rewriteManip.c.

{
    if (node == NULL)
        return false;
    if (IsA(node, Var))
    {
        Var        *var = (Var *) node;
 
        if (var->varlevelsup == context->sublevels_up)
        {
            var->varno += context->offset;
            var->varnullingrels = offset_relid_set(var->varnullingrels,
                                                   context->offset);
            if (var->varnosyn > 0)
                var->varnosyn += context->offset;
        }
        return false;
    }
    if (IsA(node, CurrentOfExpr))
    {
        CurrentOfExpr *cexpr = (CurrentOfExpr *) node;
 
        if (context->sublevels_up == 0)
            cexpr->cvarno += context->offset;
        return false;
    }
    if (IsA(node, RangeTblRef))
    {
        RangeTblRef *rtr = (RangeTblRef *) node;
 
        if (context->sublevels_up == 0)
            rtr->rtindex += context->offset;
        /* the subquery itself is visited separately */
        return false;
    }
    if (IsA(node, JoinExpr))
    {
        JoinExpr   *j = (JoinExpr *) node;
 
        if (j->rtindex && context->sublevels_up == 0)
            j->rtindex += context->offset;
        /* fall through to examine children */
    }
    if (IsA(node, PlaceHolderVar))
    {
        PlaceHolderVar *phv = (PlaceHolderVar *) node;
 
        if (phv->phlevelsup == context->sublevels_up)
        {
            phv->phrels = offset_relid_set(phv->phrels,
                                           context->offset);
            phv->phnullingrels = offset_relid_set(phv->phnullingrels,
                                                  context->offset);
        }
        /* fall through to examine children */
    }
    if (IsA(node, AppendRelInfo))
    {
        AppendRelInfo *appinfo = (AppendRelInfo *) node;
 
        if (context->sublevels_up == 0)
        {
            appinfo->parent_relid += context->offset;
            appinfo->child_relid += context->offset;
        }
        /* fall through to examine children */
    }
    /* Shouldn't need to handle other planner auxiliary nodes here */
    Assert(!IsA(node, PlanRowMark));
    Assert(!IsA(node, SpecialJoinInfo));
    Assert(!IsA(node, PlaceHolderInfo));
    Assert(!IsA(node, MinMaxAggInfo));
 
    if (IsA(node, Query))
    {
        /* Recurse into subselects */
        bool        result;
 
        context->sublevels_up++;
        result = query_tree_walker((Query *) node, OffsetVarNodes_walker,
                                   (void *) context, 0);
        context->sublevels_up--;
        return result;
    }
    return expression_tree_walker(node, OffsetVarNodes_walker,
                                  (void *) context);
}

References Assert(), AppendRelInfo::child_relid, CurrentOfExpr::cvarno, expression_tree_walker, IsA, j, OffsetVarNodes_context::offset, offset_relid_set(), AppendRelInfo::parent_relid, PlaceHolderVar::phlevelsup, PlaceHolderVar::phnullingrels, query_tree_walker, RangeTblRef::rtindex, OffsetVarNodes_context::sublevels_up, Var::varlevelsup, and Var::varno.

Referenced by OffsetVarNodes().

rangeTableEntry_used()

bool rangeTableEntry_used	(	Node *	node,
		int	rt_index,
		int	sublevels_up
	)

Definition at line 958 of file rewriteManip.c.

{
    rangeTableEntry_used_context context;
 
    context.rt_index = rt_index;
    context.sublevels_up = sublevels_up;
 
    /*
     * Must be prepared to start with a Query or a bare expression tree; if
     * it's a Query, we don't want to increment sublevels_up.
     */
    return query_or_expression_tree_walker(node,
                                           rangeTableEntry_used_walker,
                                           (void *) &context,
                                           0);
}

References query_or_expression_tree_walker, rangeTableEntry_used_walker(), rangeTableEntry_used_context::rt_index, and rangeTableEntry_used_context::sublevels_up.

Referenced by fireRIRrules(), matchLocks(), rewriteRuleAction(), and transformRuleStmt().

rangeTableEntry_used_walker()

static bool rangeTableEntry_used_walker ( Node *  node, rangeTableEntry_used_context *  context  )

static

Definition at line 891 of file rewriteManip.c.

{
    if (node == NULL)
        return false;
    if (IsA(node, Var))
    {
        Var        *var = (Var *) node;
 
        if (var->varlevelsup == context->sublevels_up &&
            (var->varno == context->rt_index ||
             bms_is_member(context->rt_index, var->varnullingrels)))
            return true;
        return false;
    }
    if (IsA(node, CurrentOfExpr))
    {
        CurrentOfExpr *cexpr = (CurrentOfExpr *) node;
 
        if (context->sublevels_up == 0 &&
            cexpr->cvarno == context->rt_index)
            return true;
        return false;
    }
    if (IsA(node, RangeTblRef))
    {
        RangeTblRef *rtr = (RangeTblRef *) node;
 
        if (rtr->rtindex == context->rt_index &&
            context->sublevels_up == 0)
            return true;
        /* the subquery itself is visited separately */
        return false;
    }
    if (IsA(node, JoinExpr))
    {
        JoinExpr   *j = (JoinExpr *) node;
 
        if (j->rtindex == context->rt_index &&
            context->sublevels_up == 0)
            return true;
        /* fall through to examine children */
    }
    /* Shouldn't need to handle planner auxiliary nodes here */
    Assert(!IsA(node, PlaceHolderVar));
    Assert(!IsA(node, PlanRowMark));
    Assert(!IsA(node, SpecialJoinInfo));
    Assert(!IsA(node, AppendRelInfo));
    Assert(!IsA(node, PlaceHolderInfo));
    Assert(!IsA(node, MinMaxAggInfo));
 
    if (IsA(node, Query))
    {
        /* Recurse into subselects */
        bool        result;
 
        context->sublevels_up++;
        result = query_tree_walker((Query *) node, rangeTableEntry_used_walker,
                                   (void *) context, 0);
        context->sublevels_up--;
        return result;
    }
    return expression_tree_walker(node, rangeTableEntry_used_walker,
                                  (void *) context);
}

References Assert(), bms_is_member(), CurrentOfExpr::cvarno, expression_tree_walker, IsA, j, query_tree_walker, rangeTableEntry_used_context::rt_index, RangeTblRef::rtindex, rangeTableEntry_used_context::sublevels_up, Var::varlevelsup, and Var::varno.

Referenced by rangeTableEntry_used().

remove_nulling_relids()

Node* remove_nulling_relids	(	Node *	node,
		const Bitmapset *	removable_relids,
		const Bitmapset *	except_relids
	)

Definition at line 1226 of file rewriteManip.c.

{
    remove_nulling_relids_context context;
 
    context.removable_relids = removable_relids;
    context.except_relids = except_relids;
    context.sublevels_up = 0;
    return query_or_expression_tree_mutator(node,
                                            remove_nulling_relids_mutator,
                                            &context,
                                            0);
}

References remove_nulling_relids_context::except_relids, query_or_expression_tree_mutator, remove_nulling_relids_context::removable_relids, remove_nulling_relids_mutator(), and remove_nulling_relids_context::sublevels_up.

Referenced by deconstruct_distribute_oj_quals(), have_partkey_equi_join(), reconsider_full_join_clause(), reduce_outer_joins(), and remove_useless_result_rtes().

remove_nulling_relids_mutator()

static Node * remove_nulling_relids_mutator ( Node *  node, remove_nulling_relids_context *  context  )

static

Definition at line 1242 of file rewriteManip.c.

{
    if (node == NULL)
        return NULL;
    if (IsA(node, Var))
    {
        Var        *var = (Var *) node;
 
        if (var->varlevelsup == context->sublevels_up &&
            !bms_is_member(var->varno, context->except_relids) &&
            bms_overlap(var->varnullingrels, context->removable_relids))
        {
            /* Copy the Var ... */
            var = copyObject(var);
            /* ... and replace the copy's varnullingrels field */
            var->varnullingrels = bms_difference(var->varnullingrels,
                                                 context->removable_relids);
            return (Node *) var;
        }
        /* Otherwise fall through to copy the Var normally */
    }
    else if (IsA(node, PlaceHolderVar))
    {
        PlaceHolderVar *phv = (PlaceHolderVar *) node;
 
        if (phv->phlevelsup == context->sublevels_up &&
            !bms_overlap(phv->phrels, context->except_relids))
        {
            /*
             * Note: it might seem desirable to remove the PHV altogether if
             * phnullingrels goes to empty.  Currently we dare not do that
             * because we use PHVs in some cases to enforce separate identity
             * of subexpressions; see wrap_non_vars usages in prepjointree.c.
             */
            /* Copy the PlaceHolderVar and mutate what's below ... */
            phv = (PlaceHolderVar *)
                expression_tree_mutator(node,
                                        remove_nulling_relids_mutator,
                                        (void *) context);
            /* ... and replace the copy's phnullingrels field */
            phv->phnullingrels = bms_difference(phv->phnullingrels,
                                                context->removable_relids);
            /* We must also update phrels, if it contains a removable RTI */
            phv->phrels = bms_difference(phv->phrels,
                                         context->removable_relids);
            Assert(!bms_is_empty(phv->phrels));
            return (Node *) phv;
        }
        /* Otherwise fall through to copy the PlaceHolderVar normally */
    }
    else if (IsA(node, Query))
    {
        /* Recurse into RTE or sublink subquery */
        Query      *newnode;
 
        context->sublevels_up++;
        newnode = query_tree_mutator((Query *) node,
                                     remove_nulling_relids_mutator,
                                     (void *) context,
                                     0);
        context->sublevels_up--;
        return (Node *) newnode;
    }
    return expression_tree_mutator(node, remove_nulling_relids_mutator,
                                   (void *) context);
}

References Assert(), bms_difference(), bms_is_empty, bms_is_member(), bms_overlap(), copyObject, remove_nulling_relids_context::except_relids, expression_tree_mutator, IsA, PlaceHolderVar::phlevelsup, PlaceHolderVar::phnullingrels, query_tree_mutator, remove_nulling_relids_context::removable_relids, remove_nulling_relids_context::sublevels_up, Var::varlevelsup, and Var::varno.

Referenced by remove_nulling_relids().

replace_rte_variables()

Node* replace_rte_variables	(	Node *	node,
		int	target_varno,
		int	sublevels_up,
		replace_rte_variables_callback	callback,
		void *	callback_arg,
		bool *	outer_hasSubLinks
	)

Definition at line 1334 of file rewriteManip.c.

{
    Node       *result;
    replace_rte_variables_context context;
 
    context.callback = callback;
    context.callback_arg = callback_arg;
    context.target_varno = target_varno;
    context.sublevels_up = sublevels_up;
 
    /*
     * We try to initialize inserted_sublink to true if there is no need to
     * detect new sublinks because the query already has some.
     */
    if (node && IsA(node, Query))
        context.inserted_sublink = ((Query *) node)->hasSubLinks;
    else if (outer_hasSubLinks)
        context.inserted_sublink = *outer_hasSubLinks;
    else
        context.inserted_sublink = false;
 
    /*
     * Must be prepared to start with a Query or a bare expression tree; if
     * it's a Query, we don't want to increment sublevels_up.
     */
    result = query_or_expression_tree_mutator(node,
                                              replace_rte_variables_mutator,
                                              (void *) &context,
                                              0);
 
    if (context.inserted_sublink)
    {
        if (result && IsA(result, Query))
            ((Query *) result)->hasSubLinks = true;
        else if (outer_hasSubLinks)
            *outer_hasSubLinks = true;
        else
            elog(ERROR, "replace_rte_variables inserted a SubLink, but has noplace to record it");
    }
 
    return result;
}

References replace_rte_variables_context::callback, callback(), replace_rte_variables_context::callback_arg, elog(), ERROR, replace_rte_variables_context::inserted_sublink, IsA, query_or_expression_tree_mutator, replace_rte_variables_mutator(), replace_rte_variables_context::sublevels_up, and replace_rte_variables_context::target_varno.

Referenced by pullup_replace_vars(), pullup_replace_vars_subquery(), and ReplaceVarsFromTargetList().

replace_rte_variables_mutator()

Node* replace_rte_variables_mutator	(	Node *	node,
		replace_rte_variables_context *	context
	)

Definition at line 1381 of file rewriteManip.c.

{
    if (node == NULL)
        return NULL;
    if (IsA(node, Var))
    {
        Var        *var = (Var *) node;
 
        if (var->varno == context->target_varno &&
            var->varlevelsup == context->sublevels_up)
        {
            /* Found a matching variable, make the substitution */
            Node       *newnode;
 
            newnode = context->callback(var, context);
            /* Detect if we are adding a sublink to query */
            if (!context->inserted_sublink)
                context->inserted_sublink = checkExprHasSubLink(newnode);
            return newnode;
        }
        /* otherwise fall through to copy the var normally */
    }
    else if (IsA(node, CurrentOfExpr))
    {
        CurrentOfExpr *cexpr = (CurrentOfExpr *) node;
 
        if (cexpr->cvarno == context->target_varno &&
            context->sublevels_up == 0)
        {
            /*
             * We get here if a WHERE CURRENT OF expression turns out to apply
             * to a view.  Someday we might be able to translate the
             * expression to apply to an underlying table of the view, but
             * right now it's not implemented.
             */
            ereport(ERROR,
                    (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
                     errmsg("WHERE CURRENT OF on a view is not implemented")));
        }
        /* otherwise fall through to copy the expr normally */
    }
    else if (IsA(node, Query))
    {
        /* Recurse into RTE subquery or not-yet-planned sublink subquery */
        Query      *newnode;
        bool        save_inserted_sublink;
 
        context->sublevels_up++;
        save_inserted_sublink = context->inserted_sublink;
        context->inserted_sublink = ((Query *) node)->hasSubLinks;
        newnode = query_tree_mutator((Query *) node,
                                     replace_rte_variables_mutator,
                                     (void *) context,
                                     0);
        newnode->hasSubLinks |= context->inserted_sublink;
        context->inserted_sublink = save_inserted_sublink;
        context->sublevels_up--;
        return (Node *) newnode;
    }
    return expression_tree_mutator(node, replace_rte_variables_mutator,
                                   (void *) context);
}

References replace_rte_variables_context::callback, checkExprHasSubLink(), CurrentOfExpr::cvarno, ereport, errcode(), errmsg(), ERROR, expression_tree_mutator, replace_rte_variables_context::inserted_sublink, IsA, query_tree_mutator, replace_rte_variables_context::sublevels_up, replace_rte_variables_context::target_varno, Var::varlevelsup, and Var::varno.

Referenced by pullup_replace_vars_callback(), replace_rte_variables(), and ReplaceVarsFromTargetList_callback().

ReplaceVarsFromTargetList()

Node* ReplaceVarsFromTargetList	(	Node *	node,
		int	target_varno,
		int	sublevels_up,
		RangeTblEntry *	target_rte,
		List *	targetlist,
		ReplaceVarsNoMatchOption	nomatch_option,
		int	nomatch_varno,
		bool *	outer_hasSubLinks
	)

Definition at line 1761 of file rewriteManip.c.

{
    ReplaceVarsFromTargetList_context context;
 
    context.target_rte = target_rte;
    context.targetlist = targetlist;
    context.nomatch_option = nomatch_option;
    context.nomatch_varno = nomatch_varno;
 
    return replace_rte_variables(node, target_varno, sublevels_up,
                                 ReplaceVarsFromTargetList_callback,
                                 (void *) &context,
                                 outer_hasSubLinks);
}

References ReplaceVarsFromTargetList_context::nomatch_option, ReplaceVarsFromTargetList_context::nomatch_varno, replace_rte_variables(), ReplaceVarsFromTargetList_callback(), ReplaceVarsFromTargetList_context::target_rte, and ReplaceVarsFromTargetList_context::targetlist.

Referenced by CopyAndAddInvertedQual(), rewriteRuleAction(), rewriteTargetView(), and subquery_push_qual().

ReplaceVarsFromTargetList_callback()

static Node* ReplaceVarsFromTargetList_callback ( Var *  var, replace_rte_variables_context *  context  )

static

Definition at line 1657 of file rewriteManip.c.

{
    ReplaceVarsFromTargetList_context *rcon = (ReplaceVarsFromTargetList_context *) context->callback_arg;
    TargetEntry *tle;
 
    if (var->varattno == InvalidAttrNumber)
    {
        /* Must expand whole-tuple reference into RowExpr */
        RowExpr    *rowexpr;
        List       *colnames;
        List       *fields;
 
        /*
         * If generating an expansion for a var of a named rowtype (ie, this
         * is a plain relation RTE), then we must include dummy items for
         * dropped columns.  If the var is RECORD (ie, this is a JOIN), then
         * omit dropped columns.  In the latter case, attach column names to
         * the RowExpr for use of the executor and ruleutils.c.
         */
        expandRTE(rcon->target_rte,
                  var->varno, var->varlevelsup, var->location,
                  (var->vartype != RECORDOID),
                  &colnames, &fields);
        /* Adjust the generated per-field Vars... */
        fields = (List *) replace_rte_variables_mutator((Node *) fields,
                                                        context);
        rowexpr = makeNode(RowExpr);
        rowexpr->args = fields;
        rowexpr->row_typeid = var->vartype;
        rowexpr->row_format = COERCE_IMPLICIT_CAST;
        rowexpr->colnames = (var->vartype == RECORDOID) ? colnames : NIL;
        rowexpr->location = var->location;
 
        return (Node *) rowexpr;
    }
 
    /* Normal case referencing one targetlist element */
    tle = get_tle_by_resno(rcon->targetlist, var->varattno);
 
    if (tle == NULL || tle->resjunk)
    {
        /* Failed to find column in targetlist */
        switch (rcon->nomatch_option)
        {
            case REPLACEVARS_REPORT_ERROR:
                /* fall through, throw error below */
                break;
 
            case REPLACEVARS_CHANGE_VARNO:
                var = (Var *) copyObject(var);
                var->varno = rcon->nomatch_varno;
                /* we leave the syntactic referent alone */
                return (Node *) var;
 
            case REPLACEVARS_SUBSTITUTE_NULL:
 
                /*
                 * If Var is of domain type, we should add a CoerceToDomain
                 * node, in case there is a NOT NULL domain constraint.
                 */
                return coerce_to_domain((Node *) makeNullConst(var->vartype,
                                                               var->vartypmod,
                                                               var->varcollid),
                                        InvalidOid, -1,
                                        var->vartype,
                                        COERCION_IMPLICIT,
                                        COERCE_IMPLICIT_CAST,
                                        -1,
                                        false);
        }
        elog(ERROR, "could not find replacement targetlist entry for attno %d",
             var->varattno);
        return NULL;            /* keep compiler quiet */
    }
    else
    {
        /* Make a copy of the tlist item to return */
        Expr       *newnode = copyObject(tle->expr);
 
        /* Must adjust varlevelsup if tlist item is from higher query */
        if (var->varlevelsup > 0)
            IncrementVarSublevelsUp((Node *) newnode, var->varlevelsup, 0);
 
        /*
         * Check to see if the tlist item contains a PARAM_MULTIEXPR Param,
         * and throw error if so.  This case could only happen when expanding
         * an ON UPDATE rule's NEW variable and the referenced tlist item in
         * the original UPDATE command is part of a multiple assignment. There
         * seems no practical way to handle such cases without multiple
         * evaluation of the multiple assignment's sub-select, which would
         * create semantic oddities that users of rules would probably prefer
         * not to cope with.  So treat it as an unimplemented feature.
         */
        if (contains_multiexpr_param((Node *) newnode, NULL))
            ereport(ERROR,
                    (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
                     errmsg("NEW variables in ON UPDATE rules cannot reference columns that are part of a multiple assignment in the subject UPDATE command")));
 
        return (Node *) newnode;
    }
}

References RowExpr::args, replace_rte_variables_context::callback_arg, COERCE_IMPLICIT_CAST, coerce_to_domain(), COERCION_IMPLICIT, contains_multiexpr_param(), copyObject, elog(), ereport, errcode(), errmsg(), ERROR, expandRTE(), get_tle_by_resno(), if(), IncrementVarSublevelsUp(), InvalidAttrNumber, InvalidOid, Var::location, RowExpr::location, makeNode, makeNullConst(), NIL, ReplaceVarsFromTargetList_context::nomatch_option, ReplaceVarsFromTargetList_context::nomatch_varno, replace_rte_variables_mutator(), REPLACEVARS_CHANGE_VARNO, REPLACEVARS_REPORT_ERROR, REPLACEVARS_SUBSTITUTE_NULL, ReplaceVarsFromTargetList_context::target_rte, ReplaceVarsFromTargetList_context::targetlist, Var::varattno, Var::varlevelsup, and Var::varno.

Referenced by ReplaceVarsFromTargetList().