rewriteManip.h File Reference

#include "nodes/parsenodes.h"
#include "nodes/pathnodes.h"

Include dependency graph for rewriteManip.h:

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Go to the source code of this file.

Data Structures
struct	replace_rte_variables_context
struct	ChangeVarNodes_context

Typedefs
typedef struct AttrMap	AttrMap
typedef struct replace_rte_variables_context	replace_rte_variables_context
typedef Node *(*	replace_rte_variables_callback) (const Var *var, replace_rte_variables_context *context)
typedef enum ReplaceVarsNoMatchOption	ReplaceVarsNoMatchOption
typedef struct ChangeVarNodes_context	ChangeVarNodes_context
typedef bool(*	ChangeVarNodes_callback) (Node *node, ChangeVarNodes_context *arg)

Enumerations
enum	ReplaceVarsNoMatchOption { REPLACEVARS_REPORT_ERROR , REPLACEVARS_CHANGE_VARNO , REPLACEVARS_SUBSTITUTE_NULL }

Functions
Relids	adjust_relid_set (Relids relids, int oldrelid, int newrelid)
void	CombineRangeTables (List **dst_rtable, List **dst_perminfos, List *src_rtable, List *src_perminfos)
void	OffsetVarNodes (Node *node, int offset, int sublevels_up)
void	ChangeVarNodes (Node *node, int rt_index, int new_index, int sublevels_up)
void	ChangeVarNodesExtended (Node *node, int rt_index, int new_index, int sublevels_up, ChangeVarNodes_callback callback)
bool	ChangeVarNodesWalkExpression (Node *node, ChangeVarNodes_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)
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)
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)
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)
Node *	map_variable_attnos (Node *node, int target_varno, int sublevels_up, const AttrMap *attno_map, Oid to_rowtype, bool *found_whole_row)
Node *	ReplaceVarFromTargetList (const Var *var, RangeTblEntry *target_rte, List *targetlist, int result_relation, ReplaceVarsNoMatchOption nomatch_option, int nomatch_varno)
Node *	ReplaceVarsFromTargetList (Node *node, int target_varno, int sublevels_up, RangeTblEntry *target_rte, List *targetlist, int result_relation, ReplaceVarsNoMatchOption nomatch_option, int nomatch_varno, bool *outer_hasSubLinks)

Typedef Documentation

AttrMap

typedef struct AttrMap AttrMap

Definition at line 20 of file rewriteManip.h.

ChangeVarNodes_callback

typedef bool(* ChangeVarNodes_callback) (Node *node, ChangeVarNodes_context *arg)

Definition at line 46 of file rewriteManip.h.

ChangeVarNodes_context

typedef struct ChangeVarNodes_context ChangeVarNodes_context

Definition at line 44 of file rewriteManip.h.

replace_rte_variables_callback

typedef Node *(* replace_rte_variables_callback) (const Var *var, replace_rte_variables_context *context)

Definition at line 25 of file rewriteManip.h.

replace_rte_variables_context

typedef struct replace_rte_variables_context replace_rte_variables_context

Definition at line 23 of file rewriteManip.h.

ReplaceVarsNoMatchOption

typedef enum ReplaceVarsNoMatchOption ReplaceVarsNoMatchOption

Enumeration Type Documentation

ReplaceVarsNoMatchOption

enum ReplaceVarsNoMatchOption

Enumerator
REPLACEVARS_REPORT_ERROR
REPLACEVARS_CHANGE_VARNO
REPLACEVARS_SUBSTITUTE_NULL

Definition at line 37 of file rewriteManip.h.

{
    REPLACEVARS_REPORT_ERROR,   /* throw error if no match */
    REPLACEVARS_CHANGE_VARNO,   /* change the Var's varno, nothing else */
    REPLACEVARS_SUBSTITUTE_NULL,    /* replace with a NULL Const */
} ReplaceVarsNoMatchOption;

Function Documentation

add_nulling_relids()

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

extern

Definition at line 1252 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(), mark_nullable_by_grouping(), pullup_replace_vars_callback(), and transform_MERGE_to_join().

AddInvertedQual()

void AddInvertedQual ( Query *  parsetree, Node *  qual  )

extern

Definition at line 1228 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(), fb(), IS_NOT_TRUE, and makeNode.

Referenced by CopyAndAddInvertedQual().

AddQual()

void AddQual ( Query *  parsetree, Node *  qual  )

extern

Definition at line 1160 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, fb(), IsA, Query::jointree, make_and_qual(), FromExpr::quals, Query::setOperations, and Query::utilityStmt.

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

adjust_relid_set()

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

extern

Definition at line 773 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);
        if (!IS_SPECIAL_VARNO(newrelid))
            relids = bms_add_member(relids, newrelid);
    }
    return relids;
}

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

Referenced by ChangeVarNodes_walker(), remove_rel_from_eclass(), remove_rel_from_query(), remove_self_join_rel(), replace_relid_callback(), and update_eclasses().

ChangeVarNodes()

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

extern

Definition at line 734 of file rewriteManip.c.

{
    ChangeVarNodesExtended(node, rt_index, new_index, sublevels_up, NULL);
}

References ChangeVarNodesExtended(), and fb().

Referenced by add_security_quals(), add_with_check_options(), ApplyRetrieveRule(), CopyAndAddInvertedQual(), expand_generated_columns_internal(), expand_virtual_generated_columns(), generate_query_for_graph_path(), get_element_property_expr(), get_relation_constraints(), get_relation_info(), get_relation_statistics(), infer_arbiter_indexes(), replace_property_refs_mutator(), rewriteRuleAction(), rewriteTargetView(), set_baserel_partition_constraint(), set_baserel_partition_key_exprs(), and TriggerEnabled().

ChangeVarNodesExtended()

void ChangeVarNodesExtended ( Node *  node, int  rt_index, int  new_index, int  sublevels_up, ChangeVarNodes_callback  callback  )

extern

Definition at line 678 of file rewriteManip.c.

{
    ChangeVarNodes_context context;
 
    context.rt_index = rt_index;
    context.new_index = new_index;
    context.sublevels_up = sublevels_up;
    context.callback = callback;
 
    /*
     * 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, mergeTargetRelation, 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
         * ChangeVarNodes_walker.
         */
        if (sublevels_up == 0)
        {
            ListCell   *l;
 
            if (qry->resultRelation == rt_index)
                qry->resultRelation = new_index;
 
            if (qry->mergeTargetRelation == rt_index)
                qry->mergeTargetRelation = 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, &context, 0);
    }
    else
        ChangeVarNodes_walker(node, &context);
}

References ChangeVarNodes_context::callback, callback(), 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 ChangeVarNodes(), match_unique_clauses(), remove_rel_from_eclass(), remove_rel_from_query(), remove_self_join_rel(), split_selfjoin_quals(), and update_eclasses().

ChangeVarNodesWalkExpression()

bool ChangeVarNodesWalkExpression ( Node *  node, ChangeVarNodes_context *  context  )

extern

Definition at line 758 of file rewriteManip.c.

{
    return ChangeVarNodes_walker(node, context);
}

References ChangeVarNodes_walker().

Referenced by replace_relid_callback().

checkExprHasSubLink()

bool checkExprHasSubLink ( Node *  node )

extern

Definition at line 293 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(), fb(), QTW_IGNORE_RC_SUBQUERIES, and query_or_expression_tree_walker.

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

CombineRangeTables()

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

extern

Definition at line 348 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 fb(), lfirst_node, list_concat(), and list_length().

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  )

extern

Definition at line 86 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,
                                           &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(), convert_EXISTS_to_ANY(), and transformGroupClause().

contain_windowfuncs()

bool contain_windowfuncs ( Node *  node )

extern

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(), fb(), and query_or_expression_tree_walker.

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

getInsertSelectQuery()

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

extern

Definition at line 1102 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, fb(), FromExpr::fromlist, IsA, Query::jointree, linitial, list_length(), PRS2_NEW_VARNO, PRS2_OLD_VARNO, rt_fetch, Query::rtable, and RTE_SUBQUERY.

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

IncrementVarSublevelsUp()

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

extern

Definition at line 893 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,
                                    &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(), finalize_grouping_exprs_walker(), flatten_group_exprs_mutator(), flatten_join_alias_vars_mutator(), inline_cte_walker(), pull_up_simple_subquery(), pullup_replace_vars_callback(), replace_outer_agg(), replace_outer_grouping(), replace_outer_returning(), ReplaceVarsFromTargetList_callback(), rewriteSearchAndCycle(), substitute_actual_parameters_in_from_mutator(), and substitute_grouped_columns_mutator().

IncrementVarSublevelsUp_rtable()

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

extern

Definition at line 916 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,
                       &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().

locate_agg_of_level()

int locate_agg_of_level ( Node *  node, int  levelsup  )

extern

Definition at line 150 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,
                                           &context,
                                           0);
 
    return context.agg_location;
}

References locate_agg_of_level_context::agg_location, fb(), 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_windowfunc()

int locate_windowfunc ( Node *  node )

extern

Definition at line 252 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,
                                           &context,
                                           0);
 
    return context.win_location;
}

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

Referenced by checkTargetlistEntrySQL92(), and transformWindowFuncCall().

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  )

extern

Definition at line 1714 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,
                                            &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(), createTableConstraints(), ExecInitMerge(), ExecInitPartitionInfo(), expandTableLikeClause(), generateClonedExtStatsStmt(), generateClonedIndexStmt(), map_partition_varattnos(), and MergeAttributes().

OffsetVarNodes()

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

extern

Definition at line 477 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, mergeTargetRelation, 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->mergeTargetRelation)
                qry->mergeTargetRelation += 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, &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().

rangeTableEntry_used()

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

extern

Definition at line 1070 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,
                                           &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().

remove_nulling_relids()

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

extern

Definition at line 1340 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 add_unique_group_var(), deconstruct_distribute_oj_quals(), estimate_multivariate_bucketsize(), examine_variable(), have_partkey_equi_join(), make_group_input_target(), make_pathkeys_for_sortclauses_extended(), reconsider_full_join_clause(), reduce_outer_joins(), remove_useless_result_rtes(), set_upper_references(), and split_pathtarget_walker().

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  )

extern

Definition at line 1447 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,
                                              &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(), result, 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  )

extern

Definition at line 1494 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,
                                     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, context);
}

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

Referenced by replace_rte_variables(), and replace_rte_variables_mutator().

ReplaceVarFromTargetList()

Node * ReplaceVarFromTargetList ( const Var *  var, RangeTblEntry *  target_rte, List *  targetlist, int  result_relation, ReplaceVarsNoMatchOption  nomatch_option, int  nomatch_varno  )

extern

Definition at line 1804 of file rewriteManip.c.

{
    TargetEntry *tle;
 
    if (var->varattno == InvalidAttrNumber)
    {
        /* Must expand whole-tuple reference into RowExpr */
        RowExpr    *rowexpr;
        List       *colnames;
        List       *fields;
        ListCell   *lc;
 
        /*
         * 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.
         *
         * In order to be able to cache the results, we always generate the
         * expansion with varlevelsup = 0.  The caller is responsible for
         * adjusting it if needed.
         *
         * The varreturningtype is copied onto each individual field Var, so
         * that it is handled correctly when we recurse.
         */
        expandRTE(target_rte,
                  var->varno, 0 /* not varlevelsup */ ,
                  var->varreturningtype, var->location,
                  (var->vartype != RECORDOID),
                  &colnames, &fields);
        rowexpr = makeNode(RowExpr);
        /* the fields will be set below */
        rowexpr->args = NIL;
        rowexpr->row_typeid = var->vartype;
        rowexpr->row_format = COERCE_IMPLICIT_CAST;
        rowexpr->colnames = (var->vartype == RECORDOID) ? colnames : NIL;
        rowexpr->location = var->location;
        /* Adjust the generated per-field Vars... */
        foreach(lc, fields)
        {
            Node       *field = lfirst(lc);
 
            if (field && IsA(field, Var))
                field = ReplaceVarFromTargetList((Var *) field,
                                                 target_rte,
                                                 targetlist,
                                                 result_relation,
                                                 nomatch_option,
                                                 nomatch_varno);
            rowexpr->args = lappend(rowexpr->args, field);
        }
 
        /* Wrap it in a ReturningExpr, if needed, per comments above */
        if (var->varreturningtype != VAR_RETURNING_DEFAULT)
        {
            ReturningExpr *rexpr = makeNode(ReturningExpr);
 
            rexpr->retlevelsup = 0;
            rexpr->retold = (var->varreturningtype == VAR_RETURNING_OLD);
            rexpr->retexpr = (Expr *) rowexpr;
 
            return (Node *) rexpr;
        }
 
        return (Node *) rowexpr;
    }
 
    /* Normal case referencing one targetlist element */
    tle = get_tle_by_resno(targetlist, var->varattno);
 
    if (tle == NULL || tle->resjunk)
    {
        /* Failed to find column in targetlist */
        switch (nomatch_option)
        {
            case REPLACEVARS_REPORT_ERROR:
                /* fall through, throw error below */
                break;
 
            case REPLACEVARS_CHANGE_VARNO:
                {
                    Var        *newvar = copyObject(var);
 
                    newvar->varno = nomatch_varno;
                    newvar->varlevelsup = 0;
                    /* we leave the syntactic referent alone */
                    return (Node *) newvar;
                }
 
            case REPLACEVARS_SUBSTITUTE_NULL:
                {
                    /*
                     * If Var is of domain type, we must add a CoerceToDomain
                     * node, in case there is a NOT NULL domain constraint.
                     */
                    int16       vartyplen;
                    bool        vartypbyval;
 
                    get_typlenbyval(var->vartype, &vartyplen, &vartypbyval);
                    return coerce_null_to_domain(var->vartype,
                                                 var->vartypmod,
                                                 var->varcollid,
                                                 vartyplen,
                                                 vartypbyval);
                }
        }
        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);
 
        /*
         * 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")));
 
        /* Handle any OLD/NEW RETURNING list Vars */
        if (var->varreturningtype != VAR_RETURNING_DEFAULT)
        {
            /*
             * Copy varreturningtype onto any Vars in the tlist item that
             * refer to result_relation (which had better be non-zero).
             */
            if (result_relation == 0)
                elog(ERROR, "variable returning old/new found outside RETURNING list");
 
            SetVarReturningType((Node *) newnode, result_relation,
                                0, var->varreturningtype);
 
            /* Wrap it in a ReturningExpr, if needed, per comments above */
            if (!IsA(newnode, Var) ||
                ((Var *) newnode)->varno != result_relation ||
                ((Var *) newnode)->varlevelsup != 0)
            {
                ReturningExpr *rexpr = makeNode(ReturningExpr);
 
                rexpr->retlevelsup = 0;
                rexpr->retold = (var->varreturningtype == VAR_RETURNING_OLD);
                rexpr->retexpr = newnode;
 
                newnode = (Expr *) rexpr;
            }
        }
 
        return (Node *) newnode;
    }
}

References RowExpr::args, COERCE_IMPLICIT_CAST, coerce_null_to_domain(), contains_multiexpr_param(), copyObject, elog, ereport, errcode(), errmsg, ERROR, expandRTE(), fb(), get_tle_by_resno(), get_typlenbyval(), InvalidAttrNumber, IsA, lappend(), lfirst, Var::location, RowExpr::location, makeNode, NIL, ReplaceVarFromTargetList(), REPLACEVARS_CHANGE_VARNO, REPLACEVARS_REPORT_ERROR, REPLACEVARS_SUBSTITUTE_NULL, ReturningExpr::retexpr, ReturningExpr::retlevelsup, ReturningExpr::retold, SetVarReturningType(), VAR_RETURNING_DEFAULT, VAR_RETURNING_OLD, Var::varattno, Var::varno, and Var::varreturningtype.

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

ReplaceVarsFromTargetList()

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

extern

Definition at line 1973 of file rewriteManip.c.

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

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

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