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apache / hawq / 91c45cab0e5844abfe0f398f2378637f4028fe45 / . / src / backend / optimizer / plan / setrefs.c
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/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/*-------------------------------------------------------------------------
*
* setrefs.c
* Post-processing of a completed plan tree: fix references to subplan
* vars, and compute regproc values for operators
*
* Portions Copyright (c) 2005-2008, Greenplum inc
* Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/optimizer/plan/setrefs.c,v 1.126.2.1 2007/02/16 03:49:10 tgl Exp $
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include "access/transam.h"
#include "catalog/pg_type.h"
#include "nodes/makefuncs.h"
#include "nodes/nodeFuncs.h"
#include "optimizer/clauses.h"
#include "optimizer/pathnode.h"
#include "optimizer/planmain.h"
#include "optimizer/tlist.h"
#include "parser/parsetree.h"
#include "parser/parse_relation.h"
#include "parser/parse_expr.h" /* exprType, exprTypmod */
#include "utils/lsyscache.h"
#include "utils/syscache.h"
#include "cdb/cdbhash.h"
typedef struct
{
Index varno; /* RT index of Var */
AttrNumber varattno; /* attr number of Var */
AttrNumber resno; /* TLE position of Var */
} tlist_vinfo;
typedef struct
{
List *tlist; /* underlying target list */
int num_vars; /* number of plain Var tlist entries */
bool has_non_vars; /* are there other entries? */
int cdb_num_times_referenced; /* num of Vars that referenced me */
/* array of num_vars entries: */
tlist_vinfo vars[1]; /* VARIABLE LENGTH ARRAY */
} indexed_tlist; /* VARIABLE LENGTH STRUCT */
typedef struct
{
PlannerGlobal *glob;
int rtoffset;
} fix_scan_expr_context;
typedef struct
{
PlannerGlobal *glob;
indexed_tlist *outer_itlist;
indexed_tlist *inner_itlist;
Index skip_rel;
int rtoffset;
bool use_outer_tlist_for_matching_nonvars;
bool use_inner_tlist_for_matching_nonvars;
} fix_join_expr_context;
typedef struct
{
PlannerGlobal *glob;
indexed_tlist *subplan_itlist;
int rtoffset;
bool use_scan_slot;
} fix_upper_expr_context;
/*
* Check if a Const node is a regclass value. We accept plain OID too,
* since a regclass Const will get folded to that type if it's an argument
* to oideq or similar operators. (This might result in some extraneous
* values in a plan's list of relation dependencies, but the worst result
* would be occasional useless replans.)
*/
#define ISREGCLASSCONST(con) \
(((con)->consttype == REGCLASSOID || (con)->consttype == OIDOID) && \
!(con)->constisnull)
#define fix_scan_list(glob, lst, rtoffset) \
((List *) fix_scan_expr(glob, (Node *) (lst), rtoffset))
static Plan *set_plan_refs(PlannerGlobal *glob, Plan *plan, int rtoffset);
static Plan *set_subqueryscan_references(PlannerGlobal *glob,
SubqueryScan *plan,
int rtoffset);
static bool trivial_subqueryscan(SubqueryScan *plan);
static Node *fix_scan_expr(PlannerGlobal *glob, Node *node, int rtoffset);
static Node *fix_scan_expr_mutator(Node *node, fix_scan_expr_context *context);
static bool fix_scan_expr_walker(Node *node, fix_scan_expr_context *context);
static void set_join_references(PlannerGlobal *glob, Join *join, int rtoffset);
static void set_inner_join_references(PlannerGlobal *glob, Plan *inner_plan,
indexed_tlist *outer_itlist, int rtoffset);
static void set_upper_references(PlannerGlobal *glob, Plan *plan, int rtoffset,
bool use_scan_slot);
static void set_dummy_tlist_references(Plan *plan, int rtoffset, bool use_child_targets);
static indexed_tlist *build_tlist_index(List *tlist);
static Var *search_indexed_tlist_for_var(Var *var,
indexed_tlist *itlist,
Index newvarno,
int rtoffset);
static Var *search_indexed_tlist_for_non_var(Node *node,
indexed_tlist *itlist,
Index newvarno);
static List *fix_join_expr(PlannerGlobal *glob,
List *clauses,
indexed_tlist *outer_itlist,
indexed_tlist *inner_itlist,
Index skip_rel, int rtoffset);
static Node *fix_join_expr_mutator(Node *node,
fix_join_expr_context *context);
static List *fix_hashclauses(PlannerGlobal *glob,
List *clauses,
indexed_tlist *outer_itlist,
indexed_tlist *inner_itlist,
Index skip_rel, int rtoffset);
static List *fix_child_hashclauses(PlannerGlobal *glob,
List *clauses,
indexed_tlist *outer_itlist,
indexed_tlist *inner_itlist,
Index skip_rel, int rtoffset,
Index child);
static Node *fix_upper_expr(PlannerGlobal *glob,
Node *node,
indexed_tlist *subplan_itlist,
int rtoffset,
bool use_scan_slot);
static Node *fix_upper_expr_mutator(Node *node,
fix_upper_expr_context *context);
static bool fix_opfuncids_walker(Node *node, void *context);
static void set_sa_opfuncid(ScalarArrayOpExpr *opexpr);
static bool cdb_expr_requires_full_eval(Node *node);
static Plan *cdb_insert_result_node(PlannerGlobal *glob,
Plan *plan,
int rtoffset);
static void record_plan_function_dependency(PlannerGlobal *glob,
Oid funcid);
static bool extract_query_dependencies_walker(Node *node,
PlannerGlobal *context);
/* fix the target lists of projection-incapable nodes to use the target list of the child node */
static void fix_projection_incapable_nodes(Plan *plan);
/* fix the target lists of projection-incapable nodes in subplans to use the target list of the child node */
static void fix_projection_incapable_nodes_in_subplans(PlannerGlobal *context, Plan *plan);
extern bool is_plan_node(Node *node);
#ifdef USE_ASSERT_CHECKING
#include "cdb/cdbplan.h"
/**
* This method establishes asserts on the inputs to set_plan_references.
*/
static void set_plan_references_input_asserts(PlannerGlobal *glob, Plan *plan, List *rtable)
{
Assert(glob);
Assert(plan);
/* Note that rtable MAY be NULL */
/* Ensure that plan refers to vars that have varlevelsup = 0 AND varno is in the rtable */
List *allVars = extract_nodes(glob, (Node *) plan, T_Var);
ListCell *lc = NULL;
foreach (lc, allVars)
{
Var *var = (Var *) lfirst(lc);
Assert(var->varlevelsup == 0 && "Plan contains vars that refer to outer plan.");
/**
* Append plans set varno = OUTER very early on.
*/
/**
* If shared input node exists, a subquery scan may refer to varnos outside
* its current rtable.
*/
Assert((var->varno == OUTER
|| (var->varno > 0 && var->varno <= list_length(rtable) + list_length(glob->finalrtable)))
&& "Plan contains var that refer outside the rtable.");
Assert(var->varno == var->varnoold && "Varno and varnoold do not agree!");
/** If a pseudo column, there should be a corresponding entry in the relation */
if (var->varattno <= FirstLowInvalidHeapAttributeNumber)
{
RangeTblEntry *rte = rt_fetch(var->varno, rtable);
Assert(rte);
Assert(rte->pseudocols);
Assert(list_length(rte->pseudocols) > var->varattno - FirstLowInvalidHeapAttributeNumber);
}
}
/* Ensure that all params that the plan refers to has a corresponding subplan */
List *allParams = extract_nodes(glob, (Node *) plan, T_Param);
foreach (lc, allParams)
{
Param *param = lfirst(lc);
if (param->paramkind == PARAM_EXEC)
{
Assert(param->paramid < list_length(glob->paramlist) && "Parameter ID outside range of parameters known at the global level.");
PlannerParamItem *paramItem = list_nth(glob->paramlist, param->paramid);
Assert(paramItem);
if (IsA(paramItem->item, Var))
{
Var *var = (Var *) paramItem->item;
Assert(param->paramtype == var->vartype && "Parameter type and var type do not match!");
}
else if (IsA(paramItem->item, Aggref))
{
Aggref *aggRef = (Aggref *) paramItem->item;
Assert(param->paramtype == aggRef->aggtype && "Param type and aggref type do not match!");
}
else
{
Assert("Global PlannerParamItem is not a var or an aggref node");
}
}
}
}
/**
* This method establishes asserts on the output of set_plan_references.
*/
static void set_plan_references_output_asserts(PlannerGlobal *glob, Plan *plan)
{
/**
* Ensure that all OpExprs have regproc OIDs.
*/
List *allOpExprs = extract_nodes(glob, (Node *) plan, T_OpExpr);
ListCell *lc = NULL;
foreach (lc, allOpExprs)
{
OpExpr *opExpr = (OpExpr *) lfirst(lc);
Assert(opExpr->opfuncid != InvalidOid && "No function associated with OpExpr!");
}
/**
* All vars should be INNER or OUTER or point to a relation in the glob->finalrtable.
*/
List *allVars = extract_nodes(glob, (Node *) plan, T_Var);
foreach (lc, allVars)
{
Var *var = (Var *) lfirst(lc);
Assert((var->varno == INNER
|| var->varno == OUTER
|| var->varno == 0 /* GPDB uses 0 for scan tuple slot. */
|| (var->varno > 0 && var->varno <= list_length(glob->finalrtable)))
&& "Plan contains var that refer outside the rtable.");
Assert(var->varattno > FirstLowInvalidHeapAttributeNumber && "Invalid attribute number in plan");
if (var->varno > 0 && var->varno <= list_length(glob->finalrtable))
{
List *colNames = NULL;
RangeTblEntry *rte = rt_fetch(var->varno, glob->finalrtable);
Assert(rte && "Invalid RTE");
Assert(rte->rtekind != RTE_VOID && "Var points to a void RTE!");
/* Make sure attnum refers to a column in the relation */
expandRTE(rte, var->varno, 0, -1, true, &colNames, NULL);
AssertImply(var->varattno >= 0, var->varattno <= list_length(colNames) + list_length(rte->pseudocols)); /* Only asserting on non-system attributes */
}
}
/** All subquery scan nodes should have their scanrelids point to a subquery entry in the finalrtable */
List *allSubQueryScans = extract_nodes(glob, (Node *) plan, T_SubqueryScan);
foreach (lc, allSubQueryScans)
{
SubqueryScan *subQueryScan = (SubqueryScan *) lfirst(lc);
Assert(subQueryScan->scan.scanrelid <= list_length(glob->finalrtable) && "Subquery scan's scanrelid out of range");
RangeTblEntry *rte = rt_fetch(subQueryScan->scan.scanrelid, glob->finalrtable);
Assert((rte->rtekind == RTE_SUBQUERY || rte->rtekind == RTE_CTE) && "Subquery scan should correspond to a subquery RTE or cte RTE!");
}
}
/* End of debug code */
#endif
/*****************************************************************************
*
* SUBPLAN REFERENCES
*
*****************************************************************************/
/*
* set_plan_references
*
* This is the final processing pass of the planner/optimizer. The plan
* tree is complete; we just have to adjust some representational details
* for the convenience of the executor:
*
* 1. We flatten the various subquery rangetables into a single list, and
* zero out RangeTblEntry fields that are not useful to the executor.
*
* 2. We adjust Vars in scan nodes to be consistent with the flat rangetable.
*
* 3. We adjust Vars in upper plan nodes to refer to the outputs of their
* subplans.
*
* 4. We compute regproc OIDs for operators (ie, we look up the function
* that implements each op).
*
* 5. We create lists of specific objects that the plan depends on.
*
* NB In GPDB we only build the relation list, though the apparatus is in
* place to collect PlanInvalItems when that becomes interesting.
*
* This will be used by plancache.c to drive invalidation of cached plans.
* Relation dependencies are represented by OIDs, and everything else by
* PlanInvalItems (this distinction is motivated by the shared-inval APIs).
* Currently, relations and user-defined functions are the only types of
* objects that are explicitly tracked this way.
*
* We also perform one final optimization step, which is to delete
* SubqueryScan plan nodes that aren't doing anything useful (ie, have
* no qual and a no-op targetlist). The reason for doing this last is that
* it can't readily be done before set_plan_references, because it would
* break set_upper_references: the Vars in the subquery's top tlist
* wouldn't match up with the Vars in the outer plan tree. The SubqueryScan
* serves a necessary function as a buffer between outer query and subquery
* variable numbering ... but after we've flattened the rangetable this is
* no longer a problem, since then there's only one rtindex namespace.
*
* set_plan_references recursively traverses the whole plan tree.
*
* Inputs:
* glob: global data for planner run
* plan: the topmost node of the plan
* rtable: the rangetable for the current subquery
*
* The return value is normally the same Plan node passed in, but can be
* different when the passed-in Plan is a SubqueryScan we decide isn't needed.
*
* The flattened rangetable entries are appended to glob->finalrtable, and
* plan dependencies are appended to glob->relationOids (for relations)
* and glob->invalItems (for everything else).
*
* Notice that we modify Plan nodes in-place, but use expression_tree_mutator
* to process targetlist and qual expressions. We can assume that the Plan
* nodes were just built by the planner and are not multiply referenced, but
* it's not so safe to assume that for expression tree nodes.
*/
Plan *
set_plan_references(PlannerGlobal *glob, Plan *plan, List *rtable)
{
#ifdef USE_ASSERT_CHECKING
/*
* This method formalizes our assumptions about the input to set_plan_references.
* This will hopefully, help us debug any problems.
*/
set_plan_references_input_asserts(glob, plan, rtable);
#endif
int rtoffset = list_length(glob->finalrtable);
ListCell *lc = NULL;
/*
* In the flat rangetable, we zero out substructure pointers that are not
* needed by the executor; this reduces the storage space and copying cost
* for cached plans. We keep only the alias and eref Alias fields, which
* are needed by EXPLAIN, and the selectedCols and modifiedCols bitmaps,
* which are needed for executor-startup permissions checking.
*/
foreach(lc, rtable)
{
RangeTblEntry *rte = (RangeTblEntry *) lfirst(lc);
RangeTblEntry *newrte = NULL;
/* flat copy to duplicate all the scalar fields */
newrte = copyObject(rte);
/** Need to fix up some of the references in the newly created newrte */
fix_scan_expr(glob, (Node *) newrte->funcexpr, rtoffset);
fix_scan_expr(glob, (Node *) newrte->joinaliasvars, rtoffset);
fix_scan_expr(glob, (Node *) newrte->values_lists, rtoffset);
glob->finalrtable = lappend(glob->finalrtable, newrte);
/*
* If it's a plain relation RTE, add the table to relationOids.
*
* We do this even though the RTE might be unreferenced in the plan
* tree; this would correspond to cases such as views that were
* expanded, child tables that were eliminated by constraint
* exclusion, etc. Schema invalidation on such a rel must still force
* rebuilding of the plan.
*
* Note we don't bother to avoid duplicate list entries. We could,
* but it would probably cost more cycles than it would save.
*/
if (newrte->rtekind == RTE_RELATION)
glob->relationOids = lappend_oid(glob->relationOids,
newrte->relid);
}
/* Now fix the Plan tree */
fix_projection_incapable_nodes(plan);
fix_projection_incapable_nodes_in_subplans(glob, plan);
Plan *retPlan = set_plan_refs(glob, plan, rtoffset);
#ifdef USE_ASSERT_CHECKING
/**
* Ensuring that the output of setrefs behaves as expected.
*/
set_plan_references_output_asserts(glob, retPlan);
#endif
return retPlan;
}
/*
* set_plan_refs: recurse through the Plan nodes of a single subquery level
*/
static Plan *
set_plan_refs(PlannerGlobal *glob, Plan *plan, const int rtoffset)
{
ListCell *l = NULL;
if (plan == NULL)
return NULL;
/*
* CDB: If plan has a Flow node, fix up its hashExpr to refer to the
* plan's own targetlist.
*/
if (plan->flow
&& plan->flow->hashExpr)
{
indexed_tlist *plan_itlist = build_tlist_index(plan->targetlist);
plan->flow->hashExpr =
(List *)fix_upper_expr(glob,
(Node *)plan->flow->hashExpr,
plan_itlist,
rtoffset,
false);
pfree(plan_itlist);
}
/*
* Plan-type-specific fixes
*/
switch (nodeTag(plan))
{
case T_SeqScan: /* Rely on structure equivalence */
case T_AppendOnlyScan: /* Rely on structure equivalence */
case T_ParquetScan: /* Rely on structure equivalence */
case T_ExternalScan: /* Rely on structure equivalence */
{
Scan *splan = (Scan *) plan;
if (cdb_expr_requires_full_eval((Node *)plan->targetlist))
return cdb_insert_result_node(glob, plan, rtoffset);
splan->scanrelid += rtoffset;
/* If the scan appears below a shareinput, we hit this assert. */
#ifdef USE_ASSERT_CHECKING
Assert(splan->scanrelid <= list_length(glob->finalrtable) && "Scan node's relid is outside the finalrtable!");
RangeTblEntry *rte = rt_fetch(splan->scanrelid, glob->finalrtable);
Assert(rte->rtekind == RTE_RELATION && "Scan plan should refer to a scan relation");
#endif
splan->plan.targetlist =
fix_scan_list(glob, splan->plan.targetlist, rtoffset);
splan->plan.qual =
fix_scan_list(glob, splan->plan.qual, rtoffset);
}
break;
case T_IndexScan:
{
IndexScan *splan = (IndexScan *) plan;
if (cdb_expr_requires_full_eval((Node *)plan->targetlist))
return cdb_insert_result_node(glob, plan, rtoffset);
splan->scan.scanrelid += rtoffset;
#ifdef USE_ASSERT_CHECKING
RangeTblEntry *rte = rt_fetch(splan->scan.scanrelid, glob->finalrtable);
char relstorage = get_rel_relstorage(rte->relid);
Assert(relstorage != RELSTORAGE_AOROWS &&
relstorage != RELSTORAGE_PARQUET);
#endif
splan->scan.plan.targetlist =
fix_scan_list(glob, splan->scan.plan.targetlist, rtoffset);
splan->scan.plan.qual =
fix_scan_list(glob, splan->scan.plan.qual, rtoffset);
splan->indexqual =
fix_scan_list(glob, splan->indexqual, rtoffset);
splan->indexqualorig =
fix_scan_list(glob, splan->indexqualorig, rtoffset);
}
break;
case T_BitmapIndexScan:
{
BitmapIndexScan *splan = (BitmapIndexScan *) plan;
splan->scan.scanrelid += rtoffset;
/* no need to fix targetlist and qual */
Assert(splan->scan.plan.targetlist == NIL);
Assert(splan->scan.plan.qual == NIL);
splan->indexqual =
fix_scan_list(glob, splan->indexqual, rtoffset);
splan->indexqualorig =
fix_scan_list(glob, splan->indexqualorig, rtoffset);
}
break;
case T_BitmapHeapScan:
{
BitmapHeapScan *splan = (BitmapHeapScan *) plan;
if (cdb_expr_requires_full_eval((Node *)plan->targetlist))
return cdb_insert_result_node(glob, plan, rtoffset);
splan->scan.scanrelid += rtoffset;
#ifdef USE_ASSERT_CHECKING
RangeTblEntry *rte = rt_fetch(splan->scan.scanrelid, glob->finalrtable);
char relstorage = get_rel_relstorage(rte->relid);
Assert(relstorage != RELSTORAGE_AOROWS &&
relstorage != RELSTORAGE_PARQUET);
#endif
splan->scan.plan.targetlist =
fix_scan_list(glob, splan->scan.plan.targetlist, rtoffset);
splan->scan.plan.qual =
fix_scan_list(glob, splan->scan.plan.qual, rtoffset);
splan->bitmapqualorig =
fix_scan_list(glob, splan->bitmapqualorig, rtoffset);
}
break;
case T_BitmapAppendOnlyScan:
{
BitmapAppendOnlyScan *splan = (BitmapAppendOnlyScan *) plan;
if (cdb_expr_requires_full_eval((Node *)plan->targetlist))
return cdb_insert_result_node(glob, plan, rtoffset);
splan->scan.scanrelid += rtoffset;
#ifdef USE_ASSERT_CHECKING
RangeTblEntry *rte = rt_fetch(splan->scan.scanrelid, glob->finalrtable);
char relstorage = get_rel_relstorage(rte->relid);
Assert(relstorage == RELSTORAGE_AOROWS ||
relstorage == RELSTORAGE_PARQUET);
#endif
splan->scan.plan.targetlist =
fix_scan_list(glob, splan->scan.plan.targetlist, rtoffset);
splan->scan.plan.qual =
fix_scan_list(glob, splan->scan.plan.qual, rtoffset);
splan->bitmapqualorig =
fix_scan_list(glob, splan->bitmapqualorig, rtoffset);
}
break;
case T_BitmapTableScan:
{
BitmapTableScan *splan = (BitmapTableScan *) plan;
if (cdb_expr_requires_full_eval((Node *)plan->targetlist))
return cdb_insert_result_node(glob, plan, rtoffset);
splan->scan.scanrelid += rtoffset;
splan->scan.plan.targetlist =
fix_scan_list(glob, splan->scan.plan.targetlist, rtoffset);
splan->scan.plan.qual =
fix_scan_list(glob, splan->scan.plan.qual, rtoffset);
splan->bitmapqualorig =
fix_scan_list(glob, splan->bitmapqualorig, rtoffset);
}
break;
case T_TidScan:
{
TidScan *splan = (TidScan *) plan;
if (cdb_expr_requires_full_eval((Node *)plan->targetlist))
return cdb_insert_result_node(glob, plan, rtoffset);
splan->scan.scanrelid += rtoffset;
#ifdef USE_ASSERT_CHECKING
/* We only support TidScans on heap tables currently */
RangeTblEntry *rte = rt_fetch(splan->scan.scanrelid, glob->finalrtable);
char relstorage = get_rel_relstorage(rte->relid);
Assert(relstorage == RELSTORAGE_HEAP);
#endif
splan->scan.plan.targetlist =
fix_scan_list(glob, splan->scan.plan.targetlist, rtoffset);
splan->scan.plan.qual =
fix_scan_list(glob, splan->scan.plan.qual, rtoffset);
splan->tidquals =
fix_scan_list(glob, splan->tidquals, rtoffset);
}
break;
case T_SubqueryScan:
if (cdb_expr_requires_full_eval((Node *)plan->targetlist))
return cdb_insert_result_node(glob, plan, rtoffset);
/* Needs special treatment, see comments below */
return set_subqueryscan_references(glob,
(SubqueryScan *) plan,
rtoffset);
case T_TableFunctionScan:
{
TableFunctionScan *tplan = (TableFunctionScan *) plan;
Plan *subplan = tplan->scan.plan.lefttree;
List *subrtable = tplan->subrtable;
if (cdb_expr_requires_full_eval((Node *)plan->targetlist))
return cdb_insert_result_node(glob, plan, rtoffset);
/* recursively process the subplan */
plan->lefttree = set_plan_references(glob, subplan, subrtable);
/* subrtable is no longer needed in the plan tree */
tplan->subrtable = NIL;
/* adjust for the new range table offset */
tplan->scan.scanrelid += rtoffset;
tplan->scan.plan.targetlist =
fix_scan_list(glob, tplan->scan.plan.targetlist, rtoffset);
tplan->scan.plan.qual =
fix_scan_list(glob, tplan->scan.plan.qual, rtoffset);
return plan;
}
case T_FunctionScan:
{
FunctionScan *splan = (FunctionScan *) plan;
if (cdb_expr_requires_full_eval((Node *)plan->targetlist))
return cdb_insert_result_node(glob, plan, rtoffset);
splan->scan.scanrelid += rtoffset;
splan->scan.plan.targetlist =
fix_scan_list(glob, splan->scan.plan.targetlist, rtoffset);
splan->scan.plan.qual =
fix_scan_list(glob, splan->scan.plan.qual, rtoffset);
}
break;
case T_ValuesScan:
{
ValuesScan *splan = (ValuesScan *) plan;
if (cdb_expr_requires_full_eval((Node *)plan->targetlist))
return cdb_insert_result_node(glob, plan, rtoffset);
splan->scan.scanrelid += rtoffset;
splan->scan.plan.targetlist =
fix_scan_list(glob, splan->scan.plan.targetlist, rtoffset);
splan->scan.plan.qual =
fix_scan_list(glob, splan->scan.plan.qual, rtoffset);
}
break;
case T_NestLoop:
case T_MergeJoin:
case T_HashJoin:
if (cdb_expr_requires_full_eval((Node *)plan->targetlist))
return cdb_insert_result_node(glob, plan, rtoffset);
set_join_references(glob, (Join *) plan, rtoffset);
break;
case T_Plan:
/*
* Occurs only as a temporary fake outer subplan (created just
* above) for Adaptive NJ's HJ child. This allows the HJ's outer
* subplan references to be fixed up normally while avoiding double
* fixup of the real outer subplan. By the time we arrive here,
* this node has served its purpose and is no longer needed.
* Vanish, returning a null ptr to replace the temporary fake ptr.
*
* XXX is this still needed. It it right??? bch 2010-02-07
*/
Assert(!plan->lefttree && !plan->righttree && !plan->initPlan);
break;
case T_Sort:
/* GPDB has limit/offset in the sort node as well. */
{
Sort *splan = (Sort *) plan;
set_dummy_tlist_references(plan, rtoffset, false);
Assert(splan->plan.qual == NIL);
splan->limitOffset =
fix_scan_expr(glob, splan->limitOffset, rtoffset);
splan->limitCount =
fix_scan_expr(glob, splan->limitCount, rtoffset);
}
break;
case T_Hash:
case T_Material:
case T_Unique:
case T_SetOp:
/*
* These plan types don't actually bother to evaluate their
* targetlists, because they just return their unmodified input
* tuples. Even though the targetlist won't be used by the
* executor, we fix it up for possible use by EXPLAIN (not to
* mention ease of debugging --- wrong varnos are very confusing).
*/
set_dummy_tlist_references(plan, rtoffset, false);
/*
* Since these plan types don't check quals either, we should not
* find any qual expression attached to them.
*/
Assert(plan->qual == NIL);
break;
case T_ShareInputScan:
{
ShareInputScan *sisc = (ShareInputScan *) plan;
Plan *childPlan = plan->lefttree;
if(childPlan == NULL)
{
Assert(sisc->share_type != SHARE_NOTSHARED
&& sisc->share_id >= 0
&& glob->share.sharedNodes);
childPlan = list_nth(glob->share.sharedNodes, sisc->share_id);
}
#ifdef DEBUG
Assert(childPlan && IsA(childPlan,Material) || IsA(childPlan, Sort));
if(IsA(childPlan, Material))
{
Material *shared = (Material *) childPlan;
Assert(shared->share_type != SHARE_NOTSHARED
&& shared->share_id == sisc->share_id);
}
else
{
Sort *shared = (Sort *) childPlan;
Assert(shared->share_type != SHARE_NOTSHARED
&& shared->share_id == sisc->share_id);
}
#endif
set_dummy_tlist_references(plan, rtoffset, false);
}
break;
case T_Limit:
{
Limit *splan = (Limit *) plan;
/*
* Like the plan types above, Limit doesn't evaluate its tlist
* or quals. It does have live expressions for limit/offset,
* however; and those cannot contain subplan variable refs, so
* fix_scan_expr works for them.
*/
set_dummy_tlist_references(plan, rtoffset, false);
Assert(splan->plan.qual == NIL);
splan->limitOffset =
fix_scan_expr(glob, splan->limitOffset, rtoffset);
splan->limitCount =
fix_scan_expr(glob, splan->limitCount, rtoffset);
}
break;
case T_Agg:
set_upper_references(glob, plan, rtoffset, true);
break;
case T_Window:
set_upper_references(glob, plan, rtoffset, true);
if ( plan->targetlist == NIL )
set_dummy_tlist_references(plan, rtoffset, true);
{
indexed_tlist *subplan_itlist =
build_tlist_index(plan->lefttree->targetlist);
/* Fix frame edges */
foreach (l, ((Window *) plan)->windowKeys)
{
WindowKey *win_key = (WindowKey *)lfirst(l);
WindowFrame *frame = win_key->frame;
if (frame != NULL)
{
/*
* Fix reference of frame edge expression *only*
* when the edge is DELAYED type. Otherwise it will have
* potential risk that the edge expression is converted
* to Var (see fix_upper_expr_mutator for reason), which
* cannot be evaluated in the executor's init stage.
* It is ok that DELAYED frame edges have Var, since
* they are evaluated at the executor's run time stage.
*/
if (window_edge_is_delayed(frame->trail))
frame->trail->val =
fix_upper_expr(glob, frame->trail->val,
subplan_itlist, rtoffset, true);
if (window_edge_is_delayed(frame->lead))
frame->lead->val =
fix_upper_expr(glob, frame->lead->val,
subplan_itlist, rtoffset, true);
}
}
pfree(subplan_itlist);
}
break;
case T_Result:
{
Result *splan = (Result *) plan;
/*
* Result may or may not have a subplan; if not, it's more
* like a scan node than an upper node.
*/
if (splan->plan.lefttree != NULL)
{
set_upper_references(glob, plan, rtoffset, false);
}
splan->plan.targetlist =
fix_scan_list(glob, splan->plan.targetlist, rtoffset);
splan->plan.qual =
fix_scan_list(glob, splan->plan.qual, rtoffset);
/* resconstantqual can't contain any subplan variable refs */
splan->resconstantqual =
fix_scan_expr(glob, splan->resconstantqual, rtoffset);
}
break;
case T_Repeat:
set_upper_references(glob, plan, rtoffset, false); /* GPDB code uses OUTER. */
break;
case T_Append:
{
Append *splan = (Append *) plan;
/*
* Append, like Sort et al, doesn't actually evaluate its
* targetlist or check quals.
*/
set_dummy_tlist_references(plan, rtoffset, false);
Assert(splan->plan.qual == NIL);
foreach(l, splan->appendplans)
{
lfirst(l) = set_plan_refs(glob,
(Plan *) lfirst(l),
rtoffset);
}
}
break;
case T_BitmapAnd:
{
BitmapAnd *splan = (BitmapAnd *) plan;
/* BitmapAnd works like Append, but has no tlist */
Assert(splan->plan.targetlist == NIL);
Assert(splan->plan.qual == NIL);
foreach(l, splan->bitmapplans)
{
lfirst(l) = set_plan_refs(glob,
(Plan *) lfirst(l),
rtoffset);
}
}
break;
case T_BitmapOr:
{
BitmapOr *splan = (BitmapOr *) plan;
/* BitmapOr works like Append, but has no tlist */
Assert(splan->plan.targetlist == NIL);
Assert(splan->plan.qual == NIL);
foreach(l, splan->bitmapplans)
{
lfirst(l) = set_plan_refs(glob,
(Plan *) lfirst(l),
rtoffset);
}
}
break;
case T_Motion:
{
Motion *motion = (Motion *)plan;
/* test flag to prevent processing the node multi times */
indexed_tlist *childplan_itlist =
build_tlist_index(plan->lefttree->targetlist);
motion->hashExpr = (List *)
fix_upper_expr(glob, (Node*) motion->hashExpr, childplan_itlist, rtoffset, false);
#ifdef USE_ASSERT_CHECKING
/* 1. Assert that the Motion node has same number of hash data types as that of hash expressions*/
/* 2. Motion node must have atleast one hash expression */
/* 3. If the Motion node is of type hash_motion: ensure that the expression that it is hashed on is a hashable datatype in gpdb*/
Assert(list_length(motion->hashExpr) == list_length(motion->hashDataTypes) && "Number of hash expression not equal to number of hash data types!");
if (MOTIONTYPE_HASH == motion->motionType)
{
Assert(1 <= list_length(motion->hashExpr) && "Motion node must have atleast one hash expression!");
ListCell *lcNode = NULL;
foreach(lcNode, motion->hashExpr)
{
Assert(isGreenplumDbHashable(exprType((Node *) lfirst(lcNode))) && "The expression is not GPDB hashable!");
}
}
#endif /* USE_ASSERT_CHECKING */
/* no need to fix targetlist and qual */
Assert(plan->qual == NIL);
set_dummy_tlist_references(plan, rtoffset, true);
pfree(childplan_itlist);
}
break;
default:
elog(ERROR, "unrecognized node type: %d",
(int) nodeTag(plan));
break;
}
/*
* Now recurse into child plans, if any
*
* NOTE: it is essential that we recurse into child plans AFTER we set
* subplan references in this plan's tlist and quals. If we did the
* reference-adjustments bottom-up, then we would fail to match this
* plan's var nodes against the already-modified nodes of the children.
*
*/
plan->lefttree = set_plan_refs(glob, plan->lefttree, rtoffset);
plan->righttree = set_plan_refs(glob, plan->righttree, rtoffset);
return plan;
}
/*
* set_subqueryscan_references
* Do set_plan_references processing on a SubqueryScan
*
* We try to strip out the SubqueryScan entirely; if we can't, we have
* to do the normal processing on it.
*/
static Plan *
set_subqueryscan_references(PlannerGlobal *glob,
SubqueryScan *plan,
int rtoffset)
{
Plan *result;
/* First, recursively process the subplan */
plan->subplan = set_plan_references(glob, plan->subplan, plan->subrtable);
/* subrtable is no longer needed in the plan tree */
plan->subrtable = NIL;
if (trivial_subqueryscan(plan))
{
/*
* We can omit the SubqueryScan node and just pull up the subplan.
*/
ListCell *lp,
*lc;
result = plan->subplan;
/* We have to be sure we don't lose any initplans */
result->initPlan = list_concat(plan->scan.plan.initPlan,
result->initPlan);
/*
* We also have to transfer the SubqueryScan's result-column names
* into the subplan, else columns sent to client will be improperly
* labeled if this is the topmost plan level. Copy the "source
* column" information too.
*/
forboth(lp, plan->scan.plan.targetlist, lc, result->targetlist)
{
TargetEntry *ptle = (TargetEntry *) lfirst(lp);
TargetEntry *ctle = (TargetEntry *) lfirst(lc);
ctle->resname = ptle->resname;
ctle->resorigtbl = ptle->resorigtbl;
ctle->resorigcol = ptle->resorigcol;
}
}
else
{
/*
* Keep the SubqueryScan node. We have to do the processing that
* set_plan_references would otherwise have done on it. Notice we do
* not do set_upper_references() here, because a SubqueryScan will
* always have been created with correct references to its subplan's
* outputs to begin with.
*/
plan->scan.scanrelid += rtoffset;
//Assert(plan->scan.scanrelid <= list_length(glob->finalrtable) && "Scan node's relid is outside the finalrtable!");
plan->scan.plan.targetlist =
fix_scan_list(glob, plan->scan.plan.targetlist, rtoffset);
plan->scan.plan.qual =
fix_scan_list(glob, plan->scan.plan.qual, rtoffset);
result = (Plan *) plan;
}
return result;
}
/*
* trivial_subqueryscan
* Detect whether a SubqueryScan can be deleted from the plan tree.
*
* We can delete it if it has no qual to check and the targetlist just
* regurgitates the output of the child plan.
*/
static bool
trivial_subqueryscan(SubqueryScan *plan)
{
int attrno;
ListCell *lp,
*lc;
if (plan->scan.plan.qual != NIL)
return false;
if (list_length(plan->scan.plan.targetlist) !=
list_length(plan->subplan->targetlist))
return false; /* tlists not same length */
if ( IsA(plan->subplan, Window) )
return false;
attrno = 1;
forboth(lp, plan->scan.plan.targetlist, lc, plan->subplan->targetlist)
{
TargetEntry *ptle = (TargetEntry *) lfirst(lp);
TargetEntry *ctle = (TargetEntry *) lfirst(lc);
if (ptle->resjunk != ctle->resjunk)
return false; /* tlist doesn't match junk status */
/*
* We accept either a Var referencing the corresponding element of the
* subplan tlist, or a Const equaling the subplan element. See
* generate_setop_tlist() for motivation.
*/
if (ptle->expr && IsA(ptle->expr, Var))
{
Var *var = (Var *) ptle->expr;
Assert(var->varlevelsup == 0);
if (var->varattno != attrno)
return false; /* out of order */
}
else if (ptle->expr && IsA(ptle->expr, Const))
{
if (!equal(ptle->expr, ctle->expr))
return false;
}
else
return false;
attrno++;
}
return true;
}
/*
* copyVar
* Copy a Var node.
*
* fix_scan_expr and friends do this enough times that it's worth having
* a bespoke routine instead of using the generic copyObject() function.
*/
static inline Var *
copyVar(Var *var)
{
Var *newvar = (Var *) palloc(sizeof(Var));
*newvar = *var;
return newvar;
}
/*
* fix_expr_common
* Do generic set_plan_references processing on an expression node
*
* This is code that is common to all variants of expression-fixing.
* We must look up operator opcode info for OpExpr and related nodes,
* add OIDs from regclass Const nodes into glob->relationOids,
* and add catalog TIDs for user-defined functions into glob->invalItems.
*
* We assume it's okay to update opcode info in-place. So this could possibly
* scribble on the planner's input data structures, but it's OK.
*/
static void
fix_expr_common(PlannerGlobal *glob, Node *node)
{
/* We assume callers won't call us on a NULL pointer */
if (IsA(node, Aggref))
{
record_plan_function_dependency(glob,
((Aggref *) node)->aggfnoid);
}
else if (IsA(node, WindowRef))
{
record_plan_function_dependency(glob,
((WindowRef *) node)->winfnoid);
}
else if (IsA(node, FuncExpr))
{
record_plan_function_dependency(glob,
((FuncExpr *) node)->funcid);
}
else if (IsA(node, OpExpr))
{
set_opfuncid((OpExpr *) node);
record_plan_function_dependency(glob,
((OpExpr *) node)->opfuncid);
}
else if (IsA(node, DistinctExpr))
{
set_opfuncid((OpExpr *) node); /* rely on struct equivalence */
record_plan_function_dependency(glob,
((DistinctExpr *) node)->opfuncid);
}
else if (IsA(node, NullIfExpr))
{
set_opfuncid((OpExpr *) node); /* rely on struct equivalence */
record_plan_function_dependency(glob,
((NullIfExpr *) node)->opfuncid);
}
else if (IsA(node, ScalarArrayOpExpr))
{
set_sa_opfuncid((ScalarArrayOpExpr *) node);
record_plan_function_dependency(glob,
((ScalarArrayOpExpr *) node)->opfuncid);
}
else if (IsA(node, Const))
{
Const *con = (Const *) node;
/* Check for regclass reference */
if (ISREGCLASSCONST(con))
glob->relationOids =
lappend_oid(glob->relationOids,
DatumGetObjectId(con->constvalue));
}
else if (IsA(node, Var))
{
Var *var = (Var *)node;
/*
* CDB: If Var node refers to a pseudo column, note its varno.
* By this point, no such Var nodes should be seen except for
* local references in Scan or Append exprs.
*
* XXX callers must reinitialize this appropriately. Ought
* to find a better way.
*/
if (var->varattno <= FirstLowInvalidHeapAttributeNumber)
{
Assert(var->varlevelsup == 0 &&
var->varno > 0 &&
var->varno <= list_length(glob->finalrtable));
}
}
}
/*
* fix_scan_expr
* Do set_plan_references processing on a scan-level expression
*
* This consists of incrementing all Vars' varnos by rtoffset,
* looking up operator opcode info for OpExpr and related nodes,
* and adding OIDs from regclass Const nodes into glob->relationOids.
*
* TODO: rename to reflect functionality more accurately.
*/
static Node *
fix_scan_expr(PlannerGlobal *glob, Node *node, int rtoffset)
{
fix_scan_expr_context context;
context.glob = glob;
context.rtoffset = rtoffset;
node = fix_scan_expr_mutator(node, &context);
return node;
}
static Node *
fix_scan_expr_mutator(Node *node, fix_scan_expr_context *context)
{
if (node == NULL)
return NULL;
if (IsA(node, Var))
{
Var *var = copyVar((Var *) node);
Assert(var->varlevelsup == 0);
/*
* We should not see any Vars marked INNER, but in a nestloop inner
* scan there could be OUTER Vars.
*/
Assert(var->varno != INNER);
if (var->varno > 0 && var->varno != OUTER)
{
var->varno += context->rtoffset;
if (var->varnoold > 0)
var->varnoold += context->rtoffset;
}
/* Pseudo column reference? */
if (var->varattno <= FirstLowInvalidHeapAttributeNumber)
{
RangeTblEntry *rte = NULL;
CdbRelColumnInfo *rci = NULL;
Node *exprCopy = NULL;
/* Look up the pseudo column definition. */
rte = rt_fetch(var->varno, context->glob->finalrtable);
rci = cdb_rte_find_pseudo_column(rte, var->varattno);
Assert(rci && rci->defexpr && "No expression for pseudo column");
exprCopy = copyObject((Node *) rci->defexpr);
/* Fill in OpExpr operator ids. */
fix_scan_expr_walker(exprCopy, context);
/* Replace the Var node with a copy of the defining expr. */
return (Node *) exprCopy;
}
else
{
return (Node *) var;
}
}
fix_expr_common(context->glob, node);
return expression_tree_mutator(node, fix_scan_expr_mutator,
(void *) context);
}
static bool
fix_scan_expr_walker(Node *node, fix_scan_expr_context *context)
{
if (node == NULL)
return false;
fix_expr_common(context->glob, node);
return expression_tree_walker(node, fix_scan_expr_walker,
(void *) context);
}
/*
* set_join_references
* Modify the target list and quals of a join node to reference its
* subplans, by setting the varnos to OUTER or INNER and setting attno
* values to the result domain number of either the corresponding outer
* or inner join tuple item. Also perform opcode lookup for these
* expressions. and add regclass OIDs to glob->relationOids.
*
* In the case of a nestloop with inner indexscan, we will also need to
* apply the same transformation to any outer vars appearing in the
* quals of the child indexscan. set_inner_join_references does that.
*/
static void
set_join_references(PlannerGlobal *glob, Join *join, int rtoffset)
{
Plan *outer_plan = join->plan.lefttree;
Plan *inner_plan = join->plan.righttree;
indexed_tlist *outer_itlist;
indexed_tlist *inner_itlist;
outer_itlist = build_tlist_index(outer_plan->targetlist);
inner_itlist = build_tlist_index(inner_plan->targetlist);
/* All join plans have tlist, qual, and joinqual */
join->plan.targetlist = fix_join_expr(glob,
join->plan.targetlist,
outer_itlist,
inner_itlist,
(Index) 0,
rtoffset);
join->plan.qual = fix_join_expr(glob,
join->plan.qual,
outer_itlist,
inner_itlist,
(Index) 0,
rtoffset);
join->joinqual = fix_join_expr(glob,
join->joinqual,
outer_itlist,
inner_itlist,
(Index) 0,
rtoffset);
/* Now do join-type-specific stuff */
if (IsA(join, NestLoop))
{
/* This processing is split out to handle possible recursion */
set_inner_join_references(glob, inner_plan, outer_itlist, rtoffset);
}
else if (IsA(join, MergeJoin))
{
MergeJoin *mj = (MergeJoin *) join;
mj->mergeclauses = fix_join_expr(glob,
mj->mergeclauses,
outer_itlist,
inner_itlist,
(Index) 0,
rtoffset);
}
else if (IsA(join, HashJoin))
{
HashJoin *hj = (HashJoin *) join;
hj->hashclauses = fix_hashclauses(glob,
hj->hashclauses,
outer_itlist,
inner_itlist,
(Index) 0,
rtoffset);
hj->hashqualclauses = fix_join_expr(glob,
hj->hashqualclauses,
outer_itlist,
inner_itlist,
(Index) 0,
rtoffset);
}
pfree(outer_itlist);
pfree(inner_itlist);
}
/*
* set_inner_join_references
* Handle join references appearing in an inner indexscan's quals
*
* To handle bitmap-scan plan trees, we have to be able to recurse down
* to the bottom BitmapIndexScan nodes; likewise, appendrel indexscans
* require recursing through Append nodes. This is split out as a separate
* function so that it can recurse.
*
* Note we do *not* apply any rtoffset for Vars of the inner relation; this is because
* the quals will be processed again by fix_scan_expr when the set_plan_refs
* recursion reaches the inner indexscan, and so we'd have done it twice.
*/
static void
set_inner_join_references(PlannerGlobal *glob, Plan *inner_plan,
indexed_tlist *outer_itlist, int rtoffset)
{
if (IsA(inner_plan, IndexScan))
{
/*
* An index is being used to reduce the number of tuples scanned in
* the inner relation. If there are join clauses being used with the
* index, we must update their outer-rel var nodes to refer to the
* outer side of the join.
*/
IndexScan *innerscan = (IndexScan *) inner_plan;
List *indexqualorig = innerscan->indexqualorig;
/* No work needed if indexqual refers only to its own rel... */
if (NumRelids((Node *) indexqualorig) > 1)
{
Index innerrel = innerscan->scan.scanrelid;
/* only refs to outer vars get changed in the inner qual */
innerscan->indexqualorig = fix_join_expr(glob,
indexqualorig,
outer_itlist,
NULL,
innerrel,
rtoffset);
innerscan->indexqual = fix_join_expr(glob,
innerscan->indexqual,
outer_itlist,
NULL,
innerrel,
rtoffset);
/*
* We must fix the inner qpqual too, if it has join clauses (this
* could happen if special operators are involved: some indexquals
* may get rechecked as qpquals).
*/
if (NumRelids((Node *) inner_plan->qual) > 1)
inner_plan->qual = fix_join_expr(glob,
inner_plan->qual,
outer_itlist,
NULL,
innerrel,
rtoffset);
}
}
else if (IsA(inner_plan, BitmapIndexScan))
{
/*
* Same, but index is being used within a bitmap plan.
*/
BitmapIndexScan *innerscan = (BitmapIndexScan *) inner_plan;
List *indexqualorig = innerscan->indexqualorig;
/* No work needed if indexqual refers only to its own rel... */
if (NumRelids((Node *) indexqualorig) > 1)
{
Index innerrel = innerscan->scan.scanrelid;
/* only refs to outer vars get changed in the inner qual */
innerscan->indexqualorig = fix_join_expr(glob,
indexqualorig,
outer_itlist,
NULL,
innerrel,
rtoffset);
innerscan->indexqual = fix_join_expr(glob,
innerscan->indexqual,
outer_itlist,
NULL,
innerrel,
rtoffset);
/* no need to fix inner qpqual */
Assert(inner_plan->qual == NIL);
}
}
else if (IsA(inner_plan, BitmapHeapScan) ||
IsA(inner_plan, BitmapAppendOnlyScan))
{
/*
* The inner side is a bitmap scan plan. Fix the top node, and
* recurse to get the lower nodes.
*
* Note: create_bitmap_scan_plan removes clauses from bitmapqualorig
* if they are duplicated in qpqual, so must test these independently.
*/
Index innerrel;
List **bitmapqualorig_p;
if (IsA(inner_plan, BitmapHeapScan))
{
BitmapHeapScan *innerscan = (BitmapHeapScan *) inner_plan;
innerrel = innerscan->scan.scanrelid;
bitmapqualorig_p = &(innerscan->bitmapqualorig);
}
else
{
Assert(IsA(inner_plan, BitmapAppendOnlyScan));
BitmapAppendOnlyScan *innerscan = (BitmapAppendOnlyScan *) inner_plan;
innerrel = innerscan->scan.scanrelid;
bitmapqualorig_p = &(innerscan->bitmapqualorig);
}
/* only refs to outer vars get changed in the inner qual */
if (NumRelids((Node *) (*bitmapqualorig_p)) > 1)
*bitmapqualorig_p = fix_join_expr(glob,
*bitmapqualorig_p,
outer_itlist,
NULL,
innerrel,
rtoffset);
/*
* We must fix the inner qpqual too, if it has join clauses (this
* could happen if special operators are involved: some indexquals may
* get rechecked as qpquals).
*/
if (NumRelids((Node *) inner_plan->qual) > 1)
inner_plan->qual = fix_join_expr(glob,
inner_plan->qual,
outer_itlist,
NULL,
innerrel,
rtoffset);
/* Now recurse */
set_inner_join_references(glob, inner_plan->lefttree, outer_itlist, rtoffset);
}
else if (IsA(inner_plan, BitmapAnd))
{
/* All we need do here is recurse */
BitmapAnd *innerscan = (BitmapAnd *) inner_plan;
ListCell *l;
foreach(l, innerscan->bitmapplans)
{
set_inner_join_references(glob, (Plan *) lfirst(l), outer_itlist, rtoffset);
}
}
else if (IsA(inner_plan, BitmapOr))
{
/* All we need do here is recurse */
BitmapOr *innerscan = (BitmapOr *) inner_plan;
ListCell *l;
foreach(l, innerscan->bitmapplans)
{
set_inner_join_references(glob, (Plan *) lfirst(l), outer_itlist, rtoffset);
}
}
else if (IsA(inner_plan, TidScan))
{
TidScan *innerscan = (TidScan *) inner_plan;
Index innerrel = innerscan->scan.scanrelid;
innerscan->tidquals = fix_join_expr(glob,
innerscan->tidquals,
outer_itlist,
NULL,
innerrel,
rtoffset);
}
else if (IsA(inner_plan, Append))
{
/*
* The inner side is an append plan. Recurse to see if it contains
* indexscans that need to be fixed.
*/
Append *appendplan = (Append *) inner_plan;
ListCell *l;
foreach(l, appendplan->appendplans)
{
set_inner_join_references(glob, (Plan *) lfirst(l), outer_itlist, rtoffset);
}
}
else if (IsA(inner_plan, Result))
{
/* Recurse through a gating Result node (similar to Append case) */
Result *result = (Result *) inner_plan;
if (result->plan.lefttree)
set_inner_join_references(glob, result->plan.lefttree, outer_itlist, rtoffset);
}
}
/*
* set_upper_references
* Update the targetlist and quals of an upper-level plan node
* to refer to the tuples returned by its lefttree subplan.
* Also perform opcode lookup for these expressions, and
* add regclass OIDs to glob->relationOids.
*
* This is used for single-input plan types like Agg, Group, Result.
*
* In most cases, we have to match up individual Vars in the tlist and
* qual expressions with elements of the subplan's tlist (which was
* generated by flatten_tlist() from these selfsame expressions, so it
* should have all the required variables). There is an important exception,
* however: GROUP BY and ORDER BY expressions will have been pushed into the
* subplan tlist unflattened. If these values are also needed in the output
* then we want to reference the subplan tlist element rather than recomputing
* the expression.
*/
static void
set_upper_references(PlannerGlobal *glob, Plan *plan,
int rtoffset, bool use_scan_slot )
{
Plan *subplan = plan->lefttree;
indexed_tlist *subplan_itlist;
List *output_targetlist;
ListCell *l;
subplan_itlist = build_tlist_index(subplan->targetlist);
output_targetlist = NIL;
foreach(l, plan->targetlist)
{
TargetEntry *tle = (TargetEntry *) lfirst(l);
Node *newexpr;
if (IsA(tle->expr, Grouping) ||
IsA(tle->expr, GroupId))
newexpr = copyObject(tle->expr);
else
newexpr = fix_upper_expr(glob,
(Node *) tle->expr,
subplan_itlist,
rtoffset,
use_scan_slot);
tle = flatCopyTargetEntry(tle);
tle->expr = (Expr *) newexpr;
output_targetlist = lappend(output_targetlist, tle);
}
plan->targetlist = output_targetlist;
plan->qual = (List *)
fix_upper_expr(glob,
(Node *) plan->qual,
subplan_itlist,
rtoffset,
use_scan_slot);
pfree(subplan_itlist);
}
/*
* set_dummy_tlist_references
* Replace the targetlist of an upper-level plan node with a simple
* list of OUTER references to its child.
*
* This is used for plan types like Sort and Append that don't evaluate
* their targetlists. Although the executor doesn't care at all what's in
* the tlist, EXPLAIN needs it to be realistic.
*
* Note: we could almost use set_upper_references() here, but it fails for
* Append for lack of a lefttree subplan. Single-purpose code is faster
* anyway.
*
* Note that old function cdb_build_identity_tlist looked into the child
* plan target list for type information, etc. The PG approach, instead,
* uses the plan's own target list, which is cleaner. The flag argument,
* use_child_targets, gives the old GPDB behavior.
*/
static void
set_dummy_tlist_references(Plan *plan, int rtoffset, bool use_child_targets)
{
List *output_targetlist;
List *input_targetlist;
ListCell *l;
output_targetlist = NIL;
if ( use_child_targets )
{
/* Note targetlist be NIL as in case of a function of no arguments */
Assert(plan->lefttree);
input_targetlist = plan->lefttree->targetlist;
}
else
{
//Assert(plan && plan->targetlist);t
input_targetlist = plan->targetlist;
}
foreach(l, input_targetlist)
{
TargetEntry *tle = (TargetEntry *) lfirst(l);
Var *oldvar = (Var *) tle->expr;
Var *newvar;
newvar = makeVar(OUTER,
tle->resno,
exprType((Node *) oldvar),
exprTypmod((Node *) oldvar),
0);
if (IsA(oldvar, Var))
{
newvar->varnoold = oldvar->varno + rtoffset;
newvar->varoattno = oldvar->varattno;
}
else
{
newvar->varnoold = 0; /* wasn't ever a plain Var */
newvar->varoattno = 0;
}
tle = flatCopyTargetEntry(tle);
tle->expr = (Expr *) newvar;
output_targetlist = lappend(output_targetlist, tle);
}
plan->targetlist = output_targetlist;
/* We don't touch plan->qual here */
}
/*
* build_tlist_index --- build an index data structure for a child tlist
*
* In most cases, subplan tlists will be "flat" tlists with only Vars,
* so we try to optimize that case by extracting information about Vars
* in advance. Matching a parent tlist to a child is still an O(N^2)
* operation, but at least with a much smaller constant factor than plain
* tlist_member() searches.
*
* The result of this function is an indexed_tlist struct to pass to
* search_indexed_tlist_for_var() or search_indexed_tlist_for_non_var().
* When done, the indexed_tlist may be freed with a single pfree().
*/
static indexed_tlist *
build_tlist_index(List *tlist)
{
indexed_tlist *itlist;
tlist_vinfo *vinfo;
ListCell *l;
/* Create data structure with enough slots for all tlist entries */
itlist = (indexed_tlist *)
palloc(offsetof(indexed_tlist, vars) +
list_length(tlist) * sizeof(tlist_vinfo));
itlist->tlist = tlist;
itlist->has_non_vars = false;
itlist->cdb_num_times_referenced = 0;
/* Find the Vars and fill in the index array */
vinfo = itlist->vars;
foreach(l, tlist)
{
TargetEntry *tle = (TargetEntry *) lfirst(l);
Expr *expr = tle->expr;
Assert(expr);
/*
* Allow a Var in parent node's expr to find matching Var in tlist
* ignoring any RelabelType nodes atop the tlist Var. Also set
* has_non_vars so tlist expr can be matched as a whole.
*/
while (IsA(expr, RelabelType))
{
expr = ((RelabelType *)expr)->arg;
itlist->has_non_vars = true;
}
if (expr && IsA(expr, Var))
{
Var *var = (Var *) expr;
vinfo->varno = var->varno;
vinfo->varattno = var->varattno;
vinfo->resno = tle->resno;
vinfo++;
}
else
itlist->has_non_vars = true;
}
itlist->num_vars = (vinfo - itlist->vars);
return itlist;
}
/*
* build_tlist_index_other_vars --- build a restricted tlist index
*
* This is like build_tlist_index, but we only index tlist entries that
* are Vars belonging to some rel other than the one specified.
*/
static indexed_tlist *
build_tlist_index_other_vars(List *tlist, Index ignore_rel)
{
indexed_tlist *itlist;
tlist_vinfo *vinfo;
ListCell *l;
/* Create data structure with enough slots for all tlist entries */
itlist = (indexed_tlist *)
palloc(offsetof(indexed_tlist, vars) +
list_length(tlist) * sizeof(tlist_vinfo));
itlist->tlist = tlist;
itlist->has_non_vars = false;
/* Find the desired Vars and fill in the index array */
vinfo = itlist->vars;
foreach(l, tlist)
{
TargetEntry *tle = (TargetEntry *) lfirst(l);
if (tle->expr && IsA(tle->expr, Var))
{
Var *var = (Var *) tle->expr;
if (var->varno != ignore_rel)
{
vinfo->varno = var->varno;
vinfo->varattno = var->varattno;
vinfo->resno = tle->resno;
vinfo++;
}
}
}
itlist->num_vars = (vinfo - itlist->vars);
return itlist;
}
/*
* search_indexed_tlist_for_var --- find a Var in an indexed tlist
*
* If a match is found, return a copy of the given Var with suitably
* modified varno/varattno (to wit, newvarno and the resno of the TLE entry).
* Also ensure that varnoold is incremented by rtoffset.
* If no match, return NULL.
*/
static Var *
search_indexed_tlist_for_var(Var *var, indexed_tlist *itlist,
Index newvarno, int rtoffset)
{
Index varno = var->varno;
AttrNumber varattno = var->varattno;
tlist_vinfo *vinfo;
int i;
vinfo = itlist->vars;
i = itlist->num_vars;
while (i-- > 0)
{
if (vinfo->varno == varno && vinfo->varattno == varattno)
{
/* Found a match */
Var *newvar = copyVar(var);
newvar->varno = newvarno;
newvar->varattno = vinfo->resno;
itlist->cdb_num_times_referenced++;
if (newvar->varnoold > 0)
{
newvar->varnoold += rtoffset;
}
return newvar;
}
vinfo++;
}
return NULL; /* no match */
}
/*
* search_indexed_tlist_for_non_var --- find a non-Var in an indexed tlist
*
* If a match is found, return a Var constructed to reference the tlist item.
* If no match, return NULL.
*
* NOTE: it is a waste of time to call this unless itlist->has_ph_vars or
* itlist->has_non_vars
*/
static Var *
search_indexed_tlist_for_non_var(Node *node,
indexed_tlist *itlist, Index newvarno)
{
TargetEntry *tle;
tle = tlist_member(node, itlist->tlist);
if (tle)
{
/* Found a matching subplan output expression */
Var *newvar;
newvar = makeVar(newvarno,
tle->resno,
exprType((Node *) tle->expr),
exprTypmod((Node *) tle->expr),
0);
newvar->varnoold = 0; /* wasn't ever a plain Var */
newvar->varoattno = 0;
itlist->cdb_num_times_referenced++;
return newvar;
}
return NULL; /* no match */
}
/*
* fix_join_expr
* Create a new set of targetlist entries or join qual clauses by
* changing the varno/varattno values of variables in the clauses
* to reference target list values from the outer and inner join
* relation target lists. Also perform opcode lookup and add
* regclass OIDs to glob->relationOids.
*
* This is used in two different scenarios: a normal join clause, where
* all the Vars in the clause *must* be replaced by OUTER or INNER references;
* and an indexscan being used on the inner side of a nestloop join.
* In the latter case we want to replace the outer-relation Vars by OUTER
* references, while Vars of the inner relation should be returned without change
* (those will later be adjusted in fix_scan_list).
* (We also implement RETURNING clause fixup using this second scenario.)
*
* For a normal join, skip_rel should be zero so that any failure to
* match a Var will be reported as an error. For the indexscan case,
* pass inner_itlist = NULL and skip_rel = the (not-offseted-yet) ID
* of the inner relation.
*
* 'clauses' is the targetlist or list of join clauses
* 'outer_itlist' is the indexed target list of the outer join relation
* 'inner_itlist' is the indexed target list of the inner join relation,
* or NULL
* 'skip_rel' is either zero or the rangetable index of a relation
* whose Vars may appear in the clause without provoking an error.
* 'rtoffset' is what to add to varno for Vars of relations other than skip_rel.
*
* Returns the new expression tree. The original clause structure is
* not modified.
*/
static List *
fix_join_expr(PlannerGlobal *glob,
List *clauses,
indexed_tlist *outer_itlist,
indexed_tlist *inner_itlist,
Index skip_rel,
int rtoffset)
{
fix_join_expr_context context;
context.glob = glob;
context.outer_itlist = outer_itlist;
context.inner_itlist = inner_itlist;
context.skip_rel = skip_rel;
context.rtoffset = rtoffset;
context.use_outer_tlist_for_matching_nonvars = true;
context.use_inner_tlist_for_matching_nonvars = true;
return (List *) fix_join_expr_mutator((Node *) clauses, &context);
}
/*
* fix_hashclauses
*
* make sure that inner argument of each hashclause does not refer to
* target entries found in the target list of join's outer child
*
*/
static List *fix_hashclauses(PlannerGlobal *glob,
List *clauses,
indexed_tlist *outer_itlist,
indexed_tlist *inner_itlist,
Index skip_rel, int rtoffset)
{
Assert(clauses);
ListCell *lc = NULL;
foreach(lc, clauses)
{
Node *node = (Node *) lfirst(lc);
Assert(IsA(node, OpExpr));
OpExpr *opexpr = (OpExpr *) node;
Assert(list_length(opexpr->args) == 2);
/* extract clause arguments */
List *outer_arg = linitial(opexpr->args);
List *inner_arg = lsecond(opexpr->args);
List *new_args = NIL;
/*
* for outer argument, we cannot refer to target entries
* in join's inner child target list
* we change walker's context to guarantee this
*/
List *new_outer_arg = fix_child_hashclauses(glob,
outer_arg,
outer_itlist,
inner_itlist,
(Index) 0,
rtoffset,
OUTER);
/*
* for inner argument, we cannot refer to target entries
* in join's outer child target list, otherwise hash table
* creation could fail,
* we change walker's context to guarantee this
*/
List *new_inner_arg = fix_child_hashclauses(glob,
inner_arg,
outer_itlist,
inner_itlist,
(Index) 0,
rtoffset,
INNER);
new_args = lappend(new_args, new_outer_arg);
new_args = lappend(new_args, new_inner_arg);
/* replace old arguments with the fixed arguments */
list_free(opexpr->args);
opexpr->args = new_args;
/* fix opexpr */
fix_expr_common(glob, node);
}
return clauses;
}
/*
* fix_child_hashclauses
* A special case of fix_join_expr used to process hash join's child hashclauses.
* The main use case is MPP-18537 and MPP-21564, where we have a constant in the
* target list of hash join's child, and the constant is used when computing hash
* value of hash join's other child.
*
* Example: select * from A, B where A.i = least(B.i,4) and A.j=4;
* Here, B's hash value is least(B.i,4), and constant 4 is defined by A's target list
*
* Since during computing the hash value for a tuple on one side of hash join, we cannot access
* the target list of hash join's other child, this function skips using other target list
* when matching non-vars.
*
*/
static List *
fix_child_hashclauses(PlannerGlobal *glob,
List *clauses,
indexed_tlist *outer_itlist,
indexed_tlist *inner_itlist,
Index skip_rel,
int rtoffset,
Index child)
{
fix_join_expr_context context;
context.glob = glob;
context.outer_itlist = outer_itlist;
context.inner_itlist = inner_itlist;
context.skip_rel = skip_rel;
context.rtoffset = rtoffset;
if (INNER == child)
{
/* skips using outer target list when matching non-vars */
context.use_outer_tlist_for_matching_nonvars = false;
context.use_inner_tlist_for_matching_nonvars = true;
}
else
{
/* skips using inner target list when matching non-vars */
context.use_inner_tlist_for_matching_nonvars = false;
context.use_outer_tlist_for_matching_nonvars = true;
}
return (List *) fix_join_expr_mutator((Node *) clauses, &context);
}
static Node *
fix_join_expr_mutator(Node *node, fix_join_expr_context *context)
{
Var *newvar;
if (node == NULL)
return NULL;
if (IsA(node, Var))
{
Var *var = (Var *) node;
/* First look for the var in the input tlists */
newvar = search_indexed_tlist_for_var(var,
context->outer_itlist,
OUTER,
context->rtoffset);
if (newvar)
return (Node *) newvar;
if (context->inner_itlist)
{
newvar = search_indexed_tlist_for_var(var,
context->inner_itlist,
INNER,
context->rtoffset);
if (newvar)
return (Node *) newvar;
}
/* If it's for an skip_rel (the inner relation in an index nested loop join), return it */
if (var->varno == context->skip_rel)
{
return (Node *) var;
}
/* No referent found for Var */
elog(ERROR, "variable not found in subplan target lists");
}
if (context->outer_itlist && context->outer_itlist->has_non_vars &&
context->use_outer_tlist_for_matching_nonvars)
{
newvar = search_indexed_tlist_for_non_var(node,
context->outer_itlist,
OUTER);
if (newvar)
return (Node *) newvar;
}
if (context->inner_itlist && context->inner_itlist->has_non_vars &&
context->use_inner_tlist_for_matching_nonvars)
{
newvar = search_indexed_tlist_for_non_var(node,
context->inner_itlist,
INNER);
if (newvar)
return (Node *) newvar;
}
fix_expr_common(context->glob, node);
return expression_tree_mutator(node,
fix_join_expr_mutator,
(void *) context);
}
/*
* fix_upper_expr
* Modifies an expression tree so that all Var nodes reference outputs
* of a subplan. Also performs opcode lookup, and adds regclass OIDs to
* glob->relationOids.
*
* This is used to fix up target and qual expressions of non-join upper-level
* plan nodes.
*
* An error is raised if no matching var can be found in the subplan tlist
* --- so this routine should only be applied to nodes whose subplans'
* targetlists were generated via flatten_tlist() or some such method.
*
* If itlist->has_non_vars is true, then we try to match whole subexpressions
* against elements of the subplan tlist, so that we can avoid recomputing
* expressions that were already computed by the subplan. (This is relatively
* expensive, so we don't want to try it in the common case where the
* subplan tlist is just a flattened list of Vars.)
*
* 'node': the tree to be fixed (a target item or qual)
* 'subplan_itlist': indexed target list for subplan
* 'rtoffset': how much to increment varnoold by
*
* The resulting tree is a copy of the original in which all Var nodes have
* varno = OUTER, varattno = resno of corresponding subplan target.
* The original tree is not modified.
*
* GPDB: Some of our executor nodes use the scantuple slot. Caller may
* indicate use of 0 (instead of OUTER) for varno by passing true in
* use_scan_slot.
*
* XXX We could do away with the need for use_scan_slot by adjusting the
* executor!
*/
static Node *
fix_upper_expr(PlannerGlobal *glob,
Node *node,
indexed_tlist *subplan_itlist,
int rtoffset,
bool use_scan_slot)
{
fix_upper_expr_context context;
context.glob = glob;
context.subplan_itlist = subplan_itlist;
context.rtoffset = rtoffset;
context.use_scan_slot = use_scan_slot;
return fix_upper_expr_mutator(node, &context);
}
static Node *
fix_upper_expr_mutator(Node *node, fix_upper_expr_context *context)
{
Var *newvar;
Index slot_varno;
if (node == NULL)
return NULL;
/* GPDB executor uses scantuple instead of outertuple in some cases. */
if (context->use_scan_slot)
slot_varno = 0;
else
slot_varno = OUTER;
if (IsA(node, Var))
{
Var *var = (Var *) node;
newvar = search_indexed_tlist_for_var(var,
context->subplan_itlist,
slot_varno,
context->rtoffset);
if (!newvar)
elog(ERROR, "variable not found in subplan target list");
return (Node *) newvar;
}
/* Try matching more complex expressions too, if tlist has any */
if (context->subplan_itlist->has_non_vars && !IsA(node, GroupId))
{
newvar = search_indexed_tlist_for_non_var(node,
context->subplan_itlist,
slot_varno);
if (newvar)
return (Node *) newvar;
}
fix_expr_common(context->glob, node);
return expression_tree_mutator(node,
fix_upper_expr_mutator,
(void *) context);
}
/*
* set_returning_clause_references
* Perform setrefs.c's work on a RETURNING targetlist
*
* If the query involves more than just the result table, we have to
* adjust any Vars that refer to other tables to reference junk tlist
* entries in the top plan's targetlist. Vars referencing the result
* table should be left alone, however (the executor will evaluate them
* using the actual heap tuple, after firing triggers if any). In the
* adjusted RETURNING list, result-table Vars will still have their
* original varno, but Vars for other rels will have varno OUTER.
*
* We also must perform opcode lookup and add regclass OIDs to
* glob->relationOids.
*
* 'rlist': the RETURNING targetlist to be fixed
* 'topplan': the top Plan node for the query (not yet passed through
* set_plan_references)
* 'resultRelation': RT index of the associated result relation
*
* Note: we assume that result relations will have rtoffset zero, that is,
* they are not coming from a subplan.
*/
List *
set_returning_clause_references(PlannerGlobal *glob,
List *rlist,
Plan *topplan,
Index resultRelation)
{
indexed_tlist *itlist;
/*
* We can perform the desired Var fixup by abusing the fix_join_expr
* machinery that normally handles inner indexscan fixup. We search the
* top plan's targetlist for Vars of non-result relations, and use
* fix_join_expr to convert RETURNING Vars into references to those tlist
* entries, while leaving result-rel Vars as-is.
*
* PlaceHolderVars will also be sought in the targetlist, but no
* more-complex expressions will be. Note that it is not possible for
* a PlaceHolderVar to refer to the result relation, since the result
* is never below an outer join. If that case could happen, we'd have
* to be prepared to pick apart the PlaceHolderVar and evaluate its
* contained expression instead.
*/
itlist = build_tlist_index_other_vars(topplan->targetlist, resultRelation);
rlist = fix_join_expr(glob,
rlist,
itlist,
NULL,
resultRelation,
0);
pfree(itlist);
return rlist;
}
/*****************************************************************************
* OPERATOR REGPROC LOOKUP
*****************************************************************************/
/*
* fix_opfuncids
* Calculate opfuncid field from opno for each OpExpr node in given tree.
* The given tree can be anything expression_tree_walker handles.
*
* The argument is modified in-place. (This is OK since we'd want the
* same change for any node, even if it gets visited more than once due to
* shared structure.)
*/
void
fix_opfuncids(Node *node)
{
/* This tree walk requires no special setup, so away we go... */
fix_opfuncids_walker(node, NULL);
}
static bool
fix_opfuncids_walker(Node *node, void *context)
{
if (node == NULL)
return false;
if (IsA(node, Grouping))
return false;
if(IsA(node, GroupId))
return false;
if (IsA(node, OpExpr))
set_opfuncid((OpExpr *) node);
else if (IsA(node, DistinctExpr))
set_opfuncid((OpExpr *) node); /* rely on struct equivalence */
else if (IsA(node, NullIfExpr))
set_opfuncid((OpExpr *) node); /* rely on struct equivalence */
else if (IsA(node, ScalarArrayOpExpr))
set_sa_opfuncid((ScalarArrayOpExpr *) node);
return expression_tree_walker(node, fix_opfuncids_walker, context);
}
/*
* set_opfuncid
* Set the opfuncid (procedure OID) in an OpExpr node,
* if it hasn't been set already.
*
* Because of struct equivalence, this can also be used for
* DistinctExpr and NullIfExpr nodes.
*/
void
set_opfuncid(OpExpr *opexpr)
{
if (opexpr->opfuncid == InvalidOid)
opexpr->opfuncid = get_opcode(opexpr->opno);
}
/*
* set_sa_opfuncid
* As above, for ScalarArrayOpExpr nodes.
*/
void
set_sa_opfuncid(ScalarArrayOpExpr *opexpr)
{
if (opexpr->opfuncid == InvalidOid)
opexpr->opfuncid = get_opcode(opexpr->opno);
}
/*****************************************************************************
* QUERY DEPENDENCY MANAGEMENT
*****************************************************************************/
/* GPDB doesn't take advantage of dependency tracking at the moment
* so its contruction it is disabled. However the infrastructure is
* intact (and compiled) to make it easy to switch on in the future.
*/
static bool disable_dependency_tracking = true;
/*
* record_plan_function_dependency
* Mark the current plan as depending on a particular function.
*/
void
record_plan_function_dependency(PlannerGlobal *glob, Oid funcid)
{
Assert(funcid != InvalidOid && "Plan cannot depend on invalid function oid");
if ( disable_dependency_tracking ) return;
/*
* For performance reasons, we don't bother to track built-in functions;
* we just assume they'll never change (or at least not in ways that'd
* invalidate plans using them). For this purpose we can consider a
* built-in function to be one with OID less than FirstBootstrapObjectId.
* Note that the OID generator guarantees never to generate such an
* OID after startup, even at OID wraparound.
*/
if (funcid >= (Oid) FirstBootstrapObjectId)
{
HeapTuple func_tuple;
PlanInvalItem *inval_item;
func_tuple = SearchSysCache(PROCOID,
ObjectIdGetDatum(funcid),
0, 0, 0);
if (!HeapTupleIsValid(func_tuple))
elog(ERROR, "cache lookup failed for function %u", funcid);
inval_item = makeNode(PlanInvalItem);
/*
* It would work to use any syscache on pg_proc, but plancache.c
* expects us to use PROCOID.
*/
inval_item->cacheId = PROCOID;
inval_item->tupleId = func_tuple->t_self;
glob->invalItems = lappend(glob->invalItems, inval_item);
ReleaseSysCache(func_tuple);
}
}
/*
* extract_query_dependencies
* Given a list of not-yet-planned queries (i.e. Query nodes),
* extract their dependencies just as set_plan_references would do.
*/
void
extract_query_dependencies(List *queries,
List **relationOids,
List **invalItems)
{
PlannerGlobal glob;
if ( disable_dependency_tracking ) return;
/* Make up a dummy PlannerGlobal so we can use this module's machinery */
MemSet(&glob, 0, sizeof(glob));
glob.type = T_PlannerGlobal;
glob.relationOids = NIL;
glob.invalItems = NIL;
(void) extract_query_dependencies_walker((Node *) queries, &glob);
*relationOids = glob.relationOids;
*invalItems = glob.invalItems;
}
static bool
extract_query_dependencies_walker(Node *node, PlannerGlobal *context)
{
if (node == NULL)
return false;
/* Extract function dependencies and check for regclass Consts */
fix_expr_common(context, node);
if (IsA(node, Query))
{
Query *query = (Query *) node;
ListCell *lc;
/* Collect relation OIDs in this Query's rtable */
foreach(lc, query->rtable)
{
RangeTblEntry *rte = (RangeTblEntry *) lfirst(lc);
if (rte->rtekind == RTE_RELATION)
context->relationOids = lappend_oid(context->relationOids,
rte->relid);
}
/* And recurse into the query's subexpressions */
return query_tree_walker(query, extract_query_dependencies_walker,
(void *) context, 0);
}
return expression_tree_walker(node, extract_query_dependencies_walker,
(void *) context);
}
/*
* fix_projection_incapable_nodes
* Fix the project list of projection incapable nodes by copying the project list
* of the child node
*/
static void
fix_projection_incapable_nodes(Plan *plan)
{
if (plan == NULL)
{
return;
}
fix_projection_incapable_nodes(plan->lefttree);
fix_projection_incapable_nodes(plan->righttree);
if (IsA(plan, ShareInputScan) || IsA(plan, SetOp))
{
if (NULL != plan->lefttree)
{
insist_target_lists_aligned(plan->targetlist, plan->lefttree->targetlist);
}
if (NULL != plan->righttree)
{
insist_target_lists_aligned(plan->targetlist, plan->righttree->targetlist);
}
}
else if (!is_projection_capable_plan(plan) && !IsA(plan, Append) && NULL != plan->lefttree)
{
/*
* while Append does not evaluate projections, we cannot always copy the child's target list,
* as Append nodes are used for updating partitioned and inherited tables, in which
* cases the target lists may be legally different, e.g. in the presence of dropped columns
*/
List *oldTargetList = plan->targetlist;
plan->targetlist = copyObject(plan->lefttree->targetlist);
if (NIL != oldTargetList)
{
list_free(oldTargetList);
}
}
}
/*
* fix_projection_incapable_nodes_in_subplans
* Fix the project list of projection incapable nodes in subplans by copying the project list
* of the child node
*/
static void
fix_projection_incapable_nodes_in_subplans(PlannerGlobal *context, Plan *plan)
{
if (plan == NULL)
{
return;
}
List *subplans = extract_nodes(context, (Node*) plan, T_SubPlan);
ListCell *lcSubPlan = NULL;
foreach (lcSubPlan, subplans)
{
SubPlan *sp = lfirst(lcSubPlan);
Plan *spPlan = list_nth(context->subplans, sp->plan_id - 1);
fix_projection_incapable_nodes(spPlan);
}
}
/*
* cdb_expr_requires_full_eval
*
* Returns true if expr could call a set-returning function.
*/
bool
cdb_expr_requires_full_eval(Node *node)
{
return expression_returns_set(node);
} /* cdb_expr_requires_full_eval */
/*
* cdb_insert_result_node
*
* Adjusts the tree so that the target list of the given Plan node
* will contain only Var nodes. The old target list is moved onto
* a new Result node which will be inserted above the given node.
* This is so the executor can use a faster path to evaluate the
* given node's targetlist. Returns the new Result node.
*/
Plan *
cdb_insert_result_node(PlannerGlobal *glob, Plan *plan, int rtoffset)
{
Plan *resultplan;
Flow *flow;
Assert(!IsA(plan, Result) &&
cdb_expr_requires_full_eval((Node *)plan->targetlist));
/* Unhook the Flow node temporarily. Caller has already fixed it up. */
flow = plan->flow;
plan->flow = NULL;
/* Build a Result node to take over the targetlist from the given Plan. */
resultplan = (Plan *)make_result(plan->targetlist, NULL, plan);
/* Build a new targetlist for the given Plan, with Var nodes only. */
plan->targetlist = flatten_tlist(plan->targetlist);
/* Fix up the Result node and the Plan tree below it. */
resultplan = set_plan_refs(glob, resultplan, rtoffset);
/* Reattach the Flow node. */
resultplan->flow = flow;
return resultplan;
} /* cdb_insert_result_node */