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2ff501590b
Also performed an initial run through of upgrading our Copyright date to extend to 2005 ... first run here was very simple ... change everything where: grep 1996-2004 && the word 'Copyright' ... scanned through the generated list with 'less' first, and after, to make sure that I only picked up the right entries ...
1192 lines
34 KiB
C
1192 lines
34 KiB
C
/*-------------------------------------------------------------------------
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*
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* prepunion.c
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* Routines to plan set-operation queries. The filename is a leftover
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* from a time when only UNIONs were implemented.
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*
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* There is also some code here to support planning of queries that use
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* inheritance (SELECT FROM foo*). This no longer has much connection
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* to the processing of UNION queries, but it's still here.
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*
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*
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* Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
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* Portions Copyright (c) 1994, Regents of the University of California
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*
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*
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* IDENTIFICATION
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* $PostgreSQL: pgsql/src/backend/optimizer/prep/prepunion.c,v 1.119 2004/12/31 22:00:20 pgsql Exp $
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*
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*-------------------------------------------------------------------------
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*/
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#include "postgres.h"
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#include "access/heapam.h"
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#include "catalog/pg_type.h"
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#include "nodes/makefuncs.h"
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#include "optimizer/clauses.h"
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#include "optimizer/plancat.h"
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#include "optimizer/planmain.h"
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#include "optimizer/planner.h"
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#include "optimizer/prep.h"
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#include "optimizer/tlist.h"
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#include "parser/parse_clause.h"
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#include "parser/parse_coerce.h"
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#include "parser/parsetree.h"
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#include "utils/lsyscache.h"
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typedef struct
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{
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Index old_rt_index;
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Index new_rt_index;
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Oid old_rel_type;
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Oid new_rel_type;
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TupleDesc old_tupdesc;
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TupleDesc new_tupdesc;
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char *old_rel_name;
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char *new_rel_name;
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} adjust_inherited_attrs_context;
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static Plan *recurse_set_operations(Node *setOp, Query *parse,
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List *colTypes, bool junkOK,
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int flag, List *refnames_tlist,
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List **sortClauses);
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static Plan *generate_union_plan(SetOperationStmt *op, Query *parse,
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List *refnames_tlist, List **sortClauses);
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static Plan *generate_nonunion_plan(SetOperationStmt *op, Query *parse,
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List *refnames_tlist, List **sortClauses);
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static List *recurse_union_children(Node *setOp, Query *parse,
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SetOperationStmt *top_union,
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List *refnames_tlist);
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static List *generate_setop_tlist(List *colTypes, int flag,
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bool hack_constants,
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List *input_tlist,
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List *refnames_tlist);
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static List *generate_append_tlist(List *colTypes, bool flag,
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List *input_plans,
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List *refnames_tlist);
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static bool tlist_same_datatypes(List *tlist, List *colTypes, bool junkOK);
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static Node *adjust_inherited_attrs_mutator(Node *node,
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adjust_inherited_attrs_context *context);
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static Relids adjust_relid_set(Relids relids, Index oldrelid, Index newrelid);
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static List *adjust_inherited_tlist(List *tlist,
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adjust_inherited_attrs_context *context);
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/*
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* plan_set_operations
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*
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* Plans the queries for a tree of set operations (UNION/INTERSECT/EXCEPT)
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*
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* This routine only deals with the setOperations tree of the given query.
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* Any top-level ORDER BY requested in parse->sortClause will be added
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* when we return to grouping_planner.
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*
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* *sortClauses is an output argument: it is set to a list of SortClauses
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* representing the result ordering of the topmost set operation.
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*/
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Plan *
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plan_set_operations(Query *parse, List **sortClauses)
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{
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SetOperationStmt *topop = (SetOperationStmt *) parse->setOperations;
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Node *node;
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Query *leftmostQuery;
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Assert(topop && IsA(topop, SetOperationStmt));
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/* check for unsupported stuff */
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Assert(parse->utilityStmt == NULL);
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Assert(parse->jointree->fromlist == NIL);
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Assert(parse->jointree->quals == NULL);
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Assert(parse->groupClause == NIL);
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Assert(parse->havingQual == NULL);
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Assert(parse->distinctClause == NIL);
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/*
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* Find the leftmost component Query. We need to use its column names
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* for all generated tlists (else SELECT INTO won't work right).
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*/
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node = topop->larg;
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while (node && IsA(node, SetOperationStmt))
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node = ((SetOperationStmt *) node)->larg;
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Assert(node && IsA(node, RangeTblRef));
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leftmostQuery = rt_fetch(((RangeTblRef *) node)->rtindex,
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parse->rtable)->subquery;
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Assert(leftmostQuery != NULL);
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/*
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* Recurse on setOperations tree to generate plans for set ops. The
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* final output plan should have just the column types shown as the
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* output from the top-level node, plus possibly a resjunk working
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* column (we can rely on upper-level nodes to deal with that).
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*/
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return recurse_set_operations((Node *) topop, parse,
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topop->colTypes, true, -1,
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leftmostQuery->targetList,
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sortClauses);
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}
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/*
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* recurse_set_operations
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* Recursively handle one step in a tree of set operations
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*
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* colTypes: list of type OIDs of expected output columns
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* junkOK: if true, child resjunk columns may be left in the result
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* flag: if >= 0, add a resjunk output column indicating value of flag
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* refnames_tlist: targetlist to take column names from
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* *sortClauses: receives list of SortClauses for result plan, if any
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*/
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static Plan *
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recurse_set_operations(Node *setOp, Query *parse,
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List *colTypes, bool junkOK,
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int flag, List *refnames_tlist,
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List **sortClauses)
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{
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if (IsA(setOp, RangeTblRef))
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{
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RangeTblRef *rtr = (RangeTblRef *) setOp;
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RangeTblEntry *rte = rt_fetch(rtr->rtindex, parse->rtable);
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Query *subquery = rte->subquery;
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Plan *subplan,
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*plan;
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Assert(subquery != NULL);
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/*
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* Generate plan for primitive subquery
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*/
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subplan = subquery_planner(subquery, 0.0 /* default case */ );
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/*
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* Add a SubqueryScan with the caller-requested targetlist
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*/
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plan = (Plan *)
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make_subqueryscan(generate_setop_tlist(colTypes, flag, true,
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subplan->targetlist,
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refnames_tlist),
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NIL,
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rtr->rtindex,
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subplan);
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/*
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* We don't bother to determine the subquery's output ordering
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* since it won't be reflected in the set-op result anyhow.
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*/
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*sortClauses = NIL;
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return plan;
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}
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else if (IsA(setOp, SetOperationStmt))
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{
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SetOperationStmt *op = (SetOperationStmt *) setOp;
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Plan *plan;
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/* UNIONs are much different from INTERSECT/EXCEPT */
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if (op->op == SETOP_UNION)
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plan = generate_union_plan(op, parse, refnames_tlist,
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sortClauses);
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else
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plan = generate_nonunion_plan(op, parse, refnames_tlist,
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sortClauses);
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/*
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* If necessary, add a Result node to project the caller-requested
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* output columns.
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*
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* XXX you don't really want to know about this: setrefs.c will apply
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* replace_vars_with_subplan_refs() to the Result node's tlist.
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* This would fail if the Vars generated by generate_setop_tlist()
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* were not exactly equal() to the corresponding tlist entries of
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* the subplan. However, since the subplan was generated by
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* generate_union_plan() or generate_nonunion_plan(), and hence
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* its tlist was generated by generate_append_tlist(), this will
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* work.
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*/
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if (flag >= 0 ||
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!tlist_same_datatypes(plan->targetlist, colTypes, junkOK))
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{
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plan = (Plan *)
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make_result(generate_setop_tlist(colTypes, flag, false,
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plan->targetlist,
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refnames_tlist),
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NULL,
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plan);
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}
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return plan;
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}
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else
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{
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elog(ERROR, "unrecognized node type: %d",
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(int) nodeTag(setOp));
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return NULL; /* keep compiler quiet */
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}
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}
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/*
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* Generate plan for a UNION or UNION ALL node
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*/
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static Plan *
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generate_union_plan(SetOperationStmt *op, Query *parse,
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List *refnames_tlist,
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List **sortClauses)
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{
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List *planlist;
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List *tlist;
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Plan *plan;
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/*
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* If any of my children are identical UNION nodes (same op, all-flag,
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* and colTypes) then they can be merged into this node so that we
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* generate only one Append and Sort for the lot. Recurse to find
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* such nodes and compute their children's plans.
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*/
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planlist = list_concat(recurse_union_children(op->larg, parse,
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op, refnames_tlist),
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recurse_union_children(op->rarg, parse,
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op, refnames_tlist));
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/*
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* Generate tlist for Append plan node.
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*
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* The tlist for an Append plan isn't important as far as the Append is
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* concerned, but we must make it look real anyway for the benefit of
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* the next plan level up.
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*/
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tlist = generate_append_tlist(op->colTypes, false,
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planlist, refnames_tlist);
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/*
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* Append the child results together.
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*/
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plan = (Plan *) make_append(planlist, false, tlist);
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/*
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* For UNION ALL, we just need the Append plan. For UNION, need to
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* add Sort and Unique nodes to produce unique output.
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*/
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if (!op->all)
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{
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List *sortList;
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sortList = addAllTargetsToSortList(NULL, NIL, tlist, false);
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if (sortList)
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{
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plan = (Plan *) make_sort_from_sortclauses(parse, sortList, plan);
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plan = (Plan *) make_unique(plan, sortList);
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}
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*sortClauses = sortList;
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}
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else
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*sortClauses = NIL;
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return plan;
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}
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/*
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* Generate plan for an INTERSECT, INTERSECT ALL, EXCEPT, or EXCEPT ALL node
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*/
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static Plan *
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generate_nonunion_plan(SetOperationStmt *op, Query *parse,
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List *refnames_tlist,
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List **sortClauses)
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{
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Plan *lplan,
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*rplan,
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*plan;
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List *tlist,
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*sortList,
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*planlist,
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*child_sortclauses;
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SetOpCmd cmd;
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/* Recurse on children, ensuring their outputs are marked */
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lplan = recurse_set_operations(op->larg, parse,
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op->colTypes, false, 0,
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refnames_tlist,
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&child_sortclauses);
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rplan = recurse_set_operations(op->rarg, parse,
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op->colTypes, false, 1,
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refnames_tlist,
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&child_sortclauses);
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planlist = list_make2(lplan, rplan);
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/*
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* Generate tlist for Append plan node.
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*
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* The tlist for an Append plan isn't important as far as the Append is
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* concerned, but we must make it look real anyway for the benefit of
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* the next plan level up. In fact, it has to be real enough that the
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* flag column is shown as a variable not a constant, else setrefs.c
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* will get confused.
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*/
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tlist = generate_append_tlist(op->colTypes, true,
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planlist, refnames_tlist);
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/*
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* Append the child results together.
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*/
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plan = (Plan *) make_append(planlist, false, tlist);
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/*
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* Sort the child results, then add a SetOp plan node to generate the
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* correct output.
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*/
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sortList = addAllTargetsToSortList(NULL, NIL, tlist, false);
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if (sortList == NIL) /* nothing to sort on? */
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{
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*sortClauses = NIL;
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return plan;
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}
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plan = (Plan *) make_sort_from_sortclauses(parse, sortList, plan);
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switch (op->op)
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{
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case SETOP_INTERSECT:
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cmd = op->all ? SETOPCMD_INTERSECT_ALL : SETOPCMD_INTERSECT;
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break;
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case SETOP_EXCEPT:
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cmd = op->all ? SETOPCMD_EXCEPT_ALL : SETOPCMD_EXCEPT;
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break;
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default:
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elog(ERROR, "unrecognized set op: %d",
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(int) op->op);
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cmd = SETOPCMD_INTERSECT; /* keep compiler quiet */
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break;
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}
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plan = (Plan *) make_setop(cmd, plan, sortList, list_length(op->colTypes) + 1);
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*sortClauses = sortList;
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return plan;
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}
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/*
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* Pull up children of a UNION node that are identically-propertied UNIONs.
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*
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* NOTE: we can also pull a UNION ALL up into a UNION, since the distinct
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* output rows will be lost anyway.
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*/
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static List *
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recurse_union_children(Node *setOp, Query *parse,
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SetOperationStmt *top_union,
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List *refnames_tlist)
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{
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List *child_sortclauses;
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if (IsA(setOp, SetOperationStmt))
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{
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SetOperationStmt *op = (SetOperationStmt *) setOp;
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if (op->op == top_union->op &&
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(op->all == top_union->all || op->all) &&
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equal(op->colTypes, top_union->colTypes))
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{
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/* Same UNION, so fold children into parent's subplan list */
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return list_concat(recurse_union_children(op->larg, parse,
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top_union,
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refnames_tlist),
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recurse_union_children(op->rarg, parse,
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top_union,
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refnames_tlist));
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}
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}
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/*
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* Not same, so plan this child separately.
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*
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* Note we disallow any resjunk columns in child results. This is
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* necessary since the Append node that implements the union won't do
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* any projection, and upper levels will get confused if some of our
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* output tuples have junk and some don't. This case only arises when
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* we have an EXCEPT or INTERSECT as child, else there won't be
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* resjunk anyway.
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*/
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return list_make1(recurse_set_operations(setOp, parse,
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top_union->colTypes, false,
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-1, refnames_tlist,
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&child_sortclauses));
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}
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|
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/*
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* Generate targetlist for a set-operation plan node
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*
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* colTypes: column datatypes for non-junk columns
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* flag: -1 if no flag column needed, 0 or 1 to create a const flag column
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* hack_constants: true to copy up constants (see comments in code)
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* input_tlist: targetlist of this node's input node
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* refnames_tlist: targetlist to take column names from
|
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*/
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static List *
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generate_setop_tlist(List *colTypes, int flag,
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bool hack_constants,
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List *input_tlist,
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List *refnames_tlist)
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{
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List *tlist = NIL;
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int resno = 1;
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ListCell *i,
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*j,
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*k;
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Resdom *resdom;
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Node *expr;
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j = list_head(input_tlist);
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k = list_head(refnames_tlist);
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foreach(i, colTypes)
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{
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Oid colType = lfirst_oid(i);
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TargetEntry *inputtle = (TargetEntry *) lfirst(j);
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TargetEntry *reftle = (TargetEntry *) lfirst(k);
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int32 colTypmod;
|
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Assert(inputtle->resdom->resno == resno);
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Assert(reftle->resdom->resno == resno);
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Assert(!inputtle->resdom->resjunk);
|
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Assert(!reftle->resdom->resjunk);
|
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|
|
/*
|
|
* Generate columns referencing input columns and having
|
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* appropriate data types and column names. Insert datatype
|
|
* coercions where necessary.
|
|
*
|
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* HACK: constants in the input's targetlist are copied up as-is
|
|
* rather than being referenced as subquery outputs. This is
|
|
* mainly to ensure that when we try to coerce them to the output
|
|
* column's datatype, the right things happen for UNKNOWN
|
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* constants. But do this only at the first level of
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* subquery-scan plans; we don't want phony constants appearing in
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* the output tlists of upper-level nodes!
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*/
|
|
if (hack_constants && inputtle->expr && IsA(inputtle->expr, Const))
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expr = (Node *) inputtle->expr;
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else
|
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expr = (Node *) makeVar(0,
|
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inputtle->resdom->resno,
|
|
inputtle->resdom->restype,
|
|
inputtle->resdom->restypmod,
|
|
0);
|
|
if (inputtle->resdom->restype == colType)
|
|
{
|
|
/* no coercion needed, and believe the input typmod */
|
|
colTypmod = inputtle->resdom->restypmod;
|
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}
|
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else
|
|
{
|
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expr = coerce_to_common_type(NULL, /* no UNKNOWNs here */
|
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expr,
|
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colType,
|
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"UNION/INTERSECT/EXCEPT");
|
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colTypmod = -1;
|
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}
|
|
resdom = makeResdom((AttrNumber) resno++,
|
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colType,
|
|
colTypmod,
|
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pstrdup(reftle->resdom->resname),
|
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false);
|
|
tlist = lappend(tlist, makeTargetEntry(resdom, (Expr *) expr));
|
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j = lnext(j);
|
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k = lnext(k);
|
|
}
|
|
|
|
if (flag >= 0)
|
|
{
|
|
/* Add a resjunk flag column */
|
|
resdom = makeResdom((AttrNumber) resno++,
|
|
INT4OID,
|
|
-1,
|
|
pstrdup("flag"),
|
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true);
|
|
/* flag value is the given constant */
|
|
expr = (Node *) makeConst(INT4OID,
|
|
sizeof(int4),
|
|
Int32GetDatum(flag),
|
|
false,
|
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true);
|
|
tlist = lappend(tlist, makeTargetEntry(resdom, (Expr *) expr));
|
|
}
|
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|
|
return tlist;
|
|
}
|
|
|
|
/*
|
|
* Generate targetlist for a set-operation Append node
|
|
*
|
|
* colTypes: column datatypes for non-junk columns
|
|
* flag: true to create a flag column copied up from subplans
|
|
* input_plans: list of sub-plans of the Append
|
|
* refnames_tlist: targetlist to take column names from
|
|
*
|
|
* The entries in the Append's targetlist should always be simple Vars;
|
|
* we just have to make sure they have the right datatypes and typmods.
|
|
*/
|
|
static List *
|
|
generate_append_tlist(List *colTypes, bool flag,
|
|
List *input_plans,
|
|
List *refnames_tlist)
|
|
{
|
|
List *tlist = NIL;
|
|
int resno = 1;
|
|
ListCell *curColType;
|
|
ListCell *ref_tl_item;
|
|
int colindex;
|
|
Resdom *resdom;
|
|
Node *expr;
|
|
ListCell *planl;
|
|
int32 *colTypmods;
|
|
|
|
/*
|
|
* First extract typmods to use.
|
|
*
|
|
* If the inputs all agree on type and typmod of a particular column, use
|
|
* that typmod; else use -1.
|
|
*/
|
|
colTypmods = (int32 *) palloc(list_length(colTypes) * sizeof(int32));
|
|
|
|
foreach(planl, input_plans)
|
|
{
|
|
Plan *subplan = (Plan *) lfirst(planl);
|
|
ListCell *subtlist;
|
|
|
|
curColType = list_head(colTypes);
|
|
colindex = 0;
|
|
foreach(subtlist, subplan->targetlist)
|
|
{
|
|
TargetEntry *subtle = (TargetEntry *) lfirst(subtlist);
|
|
|
|
if (subtle->resdom->resjunk)
|
|
continue;
|
|
Assert(curColType != NULL);
|
|
if (subtle->resdom->restype == lfirst_oid(curColType))
|
|
{
|
|
/* If first subplan, copy the typmod; else compare */
|
|
if (planl == list_head(input_plans))
|
|
colTypmods[colindex] = subtle->resdom->restypmod;
|
|
else if (subtle->resdom->restypmod != colTypmods[colindex])
|
|
colTypmods[colindex] = -1;
|
|
}
|
|
else
|
|
{
|
|
/* types disagree, so force typmod to -1 */
|
|
colTypmods[colindex] = -1;
|
|
}
|
|
curColType = lnext(curColType);
|
|
colindex++;
|
|
}
|
|
Assert(curColType == NULL);
|
|
}
|
|
|
|
/*
|
|
* Now we can build the tlist for the Append.
|
|
*/
|
|
colindex = 0;
|
|
forboth(curColType, colTypes, ref_tl_item, refnames_tlist)
|
|
{
|
|
Oid colType = lfirst_oid(curColType);
|
|
int32 colTypmod = colTypmods[colindex++];
|
|
TargetEntry *reftle = (TargetEntry *) lfirst(ref_tl_item);
|
|
|
|
Assert(reftle->resdom->resno == resno);
|
|
Assert(!reftle->resdom->resjunk);
|
|
expr = (Node *) makeVar(0,
|
|
resno,
|
|
colType,
|
|
colTypmod,
|
|
0);
|
|
resdom = makeResdom((AttrNumber) resno++,
|
|
colType,
|
|
colTypmod,
|
|
pstrdup(reftle->resdom->resname),
|
|
false);
|
|
tlist = lappend(tlist, makeTargetEntry(resdom, (Expr *) expr));
|
|
}
|
|
|
|
if (flag)
|
|
{
|
|
/* Add a resjunk flag column */
|
|
resdom = makeResdom((AttrNumber) resno++,
|
|
INT4OID,
|
|
-1,
|
|
pstrdup("flag"),
|
|
true);
|
|
/* flag value is shown as copied up from subplan */
|
|
expr = (Node *) makeVar(0,
|
|
resdom->resno,
|
|
INT4OID,
|
|
-1,
|
|
0);
|
|
tlist = lappend(tlist, makeTargetEntry(resdom, (Expr *) expr));
|
|
}
|
|
|
|
pfree(colTypmods);
|
|
|
|
return tlist;
|
|
}
|
|
|
|
/*
|
|
* Does tlist have same datatypes as requested colTypes?
|
|
*
|
|
* Resjunk columns are ignored if junkOK is true; otherwise presence of
|
|
* a resjunk column will always cause a 'false' result.
|
|
*/
|
|
static bool
|
|
tlist_same_datatypes(List *tlist, List *colTypes, bool junkOK)
|
|
{
|
|
ListCell *l;
|
|
ListCell *curColType = list_head(colTypes);
|
|
|
|
foreach(l, tlist)
|
|
{
|
|
TargetEntry *tle = (TargetEntry *) lfirst(l);
|
|
|
|
if (tle->resdom->resjunk)
|
|
{
|
|
if (!junkOK)
|
|
return false;
|
|
}
|
|
else
|
|
{
|
|
if (curColType == NULL)
|
|
return false;
|
|
if (tle->resdom->restype != lfirst_oid(curColType))
|
|
return false;
|
|
curColType = lnext(curColType);
|
|
}
|
|
}
|
|
if (curColType != NULL)
|
|
return false;
|
|
return true;
|
|
}
|
|
|
|
|
|
/*
|
|
* find_all_inheritors -
|
|
* Returns a list of relation OIDs including the given rel plus
|
|
* all relations that inherit from it, directly or indirectly.
|
|
*/
|
|
List *
|
|
find_all_inheritors(Oid parentrel)
|
|
{
|
|
List *examined_relids = NIL;
|
|
List *unexamined_relids = list_make1_oid(parentrel);
|
|
|
|
/*
|
|
* While the queue of unexamined relids is nonempty, remove the first
|
|
* element, mark it examined, and find its direct descendants. NB:
|
|
* cannot use foreach(), since we modify the queue inside loop.
|
|
*/
|
|
while (unexamined_relids != NIL)
|
|
{
|
|
Oid currentrel = linitial_oid(unexamined_relids);
|
|
List *currentchildren;
|
|
|
|
unexamined_relids = list_delete_first(unexamined_relids);
|
|
examined_relids = lappend_oid(examined_relids, currentrel);
|
|
currentchildren = find_inheritance_children(currentrel);
|
|
|
|
/*
|
|
* Add to the queue only those children not already seen. This
|
|
* avoids making duplicate entries in case of multiple inheritance
|
|
* paths from the same parent. (It'll also keep us from getting
|
|
* into an infinite loop, though theoretically there can't be any
|
|
* cycles in the inheritance graph anyway.)
|
|
*/
|
|
currentchildren = list_difference_oid(currentchildren, examined_relids);
|
|
unexamined_relids = list_union_oid(unexamined_relids, currentchildren);
|
|
}
|
|
|
|
return examined_relids;
|
|
}
|
|
|
|
/*
|
|
* expand_inherited_rtentry
|
|
* Check whether a rangetable entry represents an inheritance set.
|
|
* If so, add entries for all the child tables to the query's
|
|
* rangetable, and return an integer list of RT indexes for the
|
|
* whole inheritance set (parent and children).
|
|
* If not, return NIL.
|
|
*
|
|
* Note that the original RTE is considered to represent the whole
|
|
* inheritance set. The first member of the returned list is an RTE
|
|
* for the same table, but with inh = false, to represent the parent table
|
|
* in its role as a simple member of the set. The original RT index is
|
|
* never a member of the returned list.
|
|
*
|
|
* A childless table is never considered to be an inheritance set; therefore
|
|
* the result will never be a one-element list. It'll be either empty
|
|
* or have two or more elements.
|
|
*
|
|
* Note: there are cases in which this routine will be invoked multiple
|
|
* times on the same RTE. We will generate a separate set of child RTEs
|
|
* for each invocation. This is somewhat wasteful but seems not worth
|
|
* trying to avoid.
|
|
*/
|
|
List *
|
|
expand_inherited_rtentry(Query *parse, Index rti)
|
|
{
|
|
RangeTblEntry *rte = rt_fetch(rti, parse->rtable);
|
|
Oid parentOID;
|
|
List *inhOIDs;
|
|
List *inhRTIs;
|
|
ListCell *l;
|
|
|
|
/* Does RT entry allow inheritance? */
|
|
if (!rte->inh)
|
|
return NIL;
|
|
Assert(rte->rtekind == RTE_RELATION);
|
|
/* Fast path for common case of childless table */
|
|
parentOID = rte->relid;
|
|
if (!has_subclass(parentOID))
|
|
{
|
|
/* Clear flag to save repeated tests if called again */
|
|
rte->inh = false;
|
|
return NIL;
|
|
}
|
|
/* Scan for all members of inheritance set */
|
|
inhOIDs = find_all_inheritors(parentOID);
|
|
|
|
/*
|
|
* Check that there's at least one descendant, else treat as no-child
|
|
* case. This could happen despite above has_subclass() check, if
|
|
* table once had a child but no longer does.
|
|
*/
|
|
if (list_length(inhOIDs) < 2)
|
|
{
|
|
/* Clear flag to save repeated tests if called again */
|
|
rte->inh = false;
|
|
return NIL;
|
|
}
|
|
|
|
/* OK, it's an inheritance set; expand it */
|
|
inhRTIs = NIL;
|
|
foreach(l, inhOIDs)
|
|
{
|
|
Oid childOID = lfirst_oid(l);
|
|
RangeTblEntry *childrte;
|
|
Index childRTindex;
|
|
|
|
/*
|
|
* Build an RTE for the child, and attach to query's rangetable
|
|
* list. We copy most fields of the parent's RTE, but replace
|
|
* relation OID, and set inh = false.
|
|
*/
|
|
childrte = copyObject(rte);
|
|
childrte->relid = childOID;
|
|
childrte->inh = false;
|
|
parse->rtable = lappend(parse->rtable, childrte);
|
|
childRTindex = list_length(parse->rtable);
|
|
inhRTIs = lappend_int(inhRTIs, childRTindex);
|
|
}
|
|
|
|
/*
|
|
* The executor will check the parent table's access permissions when
|
|
* it examines the parent's inheritlist entry. There's no need to
|
|
* check twice, so turn off access check bits in the original RTE.
|
|
* (If we are invoked more than once, extra copies of the child RTEs
|
|
* will also not cause duplicate permission checks.)
|
|
*/
|
|
rte->requiredPerms = 0;
|
|
|
|
return inhRTIs;
|
|
}
|
|
|
|
/*
|
|
* adjust_inherited_attrs
|
|
* Copy the specified query or expression and translate Vars referring
|
|
* to old_rt_index to refer to new_rt_index.
|
|
*
|
|
* We also adjust varattno to match the new table by column name, rather
|
|
* than column number. This hack makes it possible for child tables to have
|
|
* different column positions for the "same" attribute as a parent, which
|
|
* is necessary for ALTER TABLE ADD COLUMN.
|
|
*/
|
|
Node *
|
|
adjust_inherited_attrs(Node *node,
|
|
Index old_rt_index, Oid old_relid,
|
|
Index new_rt_index, Oid new_relid)
|
|
{
|
|
Node *result;
|
|
adjust_inherited_attrs_context context;
|
|
Relation oldrelation;
|
|
Relation newrelation;
|
|
|
|
/* Handle simple case simply... */
|
|
if (old_rt_index == new_rt_index)
|
|
{
|
|
Assert(old_relid == new_relid);
|
|
return copyObject(node);
|
|
}
|
|
|
|
/*
|
|
* We assume that by now the planner has acquired at least
|
|
* AccessShareLock on both rels, and so we need no additional lock
|
|
* now.
|
|
*/
|
|
oldrelation = heap_open(old_relid, NoLock);
|
|
newrelation = heap_open(new_relid, NoLock);
|
|
|
|
context.old_rt_index = old_rt_index;
|
|
context.new_rt_index = new_rt_index;
|
|
context.old_rel_type = oldrelation->rd_rel->reltype;
|
|
context.new_rel_type = newrelation->rd_rel->reltype;
|
|
context.old_tupdesc = RelationGetDescr(oldrelation);
|
|
context.new_tupdesc = RelationGetDescr(newrelation);
|
|
context.old_rel_name = RelationGetRelationName(oldrelation);
|
|
context.new_rel_name = RelationGetRelationName(newrelation);
|
|
|
|
/*
|
|
* Must be prepared to start with a Query or a bare expression tree.
|
|
*/
|
|
if (node && IsA(node, Query))
|
|
{
|
|
Query *newnode;
|
|
|
|
newnode = query_tree_mutator((Query *) node,
|
|
adjust_inherited_attrs_mutator,
|
|
(void *) &context,
|
|
QTW_IGNORE_RT_SUBQUERIES);
|
|
if (newnode->resultRelation == old_rt_index)
|
|
{
|
|
newnode->resultRelation = new_rt_index;
|
|
/* Fix tlist resnos too, if it's inherited UPDATE */
|
|
if (newnode->commandType == CMD_UPDATE)
|
|
newnode->targetList =
|
|
adjust_inherited_tlist(newnode->targetList,
|
|
&context);
|
|
}
|
|
result = (Node *) newnode;
|
|
}
|
|
else
|
|
result = adjust_inherited_attrs_mutator(node, &context);
|
|
|
|
heap_close(oldrelation, NoLock);
|
|
heap_close(newrelation, NoLock);
|
|
|
|
return result;
|
|
}
|
|
|
|
/*
|
|
* Translate parent's attribute number into child's.
|
|
*
|
|
* For paranoia's sake, we match type as well as attribute name.
|
|
*/
|
|
static AttrNumber
|
|
translate_inherited_attnum(AttrNumber old_attno,
|
|
adjust_inherited_attrs_context *context)
|
|
{
|
|
Form_pg_attribute att;
|
|
char *attname;
|
|
Oid atttypid;
|
|
int32 atttypmod;
|
|
int newnatts;
|
|
int i;
|
|
|
|
if (old_attno <= 0 || old_attno > context->old_tupdesc->natts)
|
|
elog(ERROR, "attribute %d of relation \"%s\" does not exist",
|
|
(int) old_attno, context->old_rel_name);
|
|
att = context->old_tupdesc->attrs[old_attno - 1];
|
|
if (att->attisdropped)
|
|
elog(ERROR, "attribute %d of relation \"%s\" does not exist",
|
|
(int) old_attno, context->old_rel_name);
|
|
attname = NameStr(att->attname);
|
|
atttypid = att->atttypid;
|
|
atttypmod = att->atttypmod;
|
|
|
|
newnatts = context->new_tupdesc->natts;
|
|
for (i = 0; i < newnatts; i++)
|
|
{
|
|
att = context->new_tupdesc->attrs[i];
|
|
if (att->attisdropped)
|
|
continue;
|
|
if (strcmp(attname, NameStr(att->attname)) == 0)
|
|
{
|
|
/* Found it, check type */
|
|
if (atttypid != att->atttypid || atttypmod != att->atttypmod)
|
|
elog(ERROR, "attribute \"%s\" of relation \"%s\" does not match parent's type",
|
|
attname, context->new_rel_name);
|
|
return (AttrNumber) (i + 1);
|
|
}
|
|
}
|
|
|
|
elog(ERROR, "attribute \"%s\" of relation \"%s\" does not exist",
|
|
attname, context->new_rel_name);
|
|
return 0; /* keep compiler quiet */
|
|
}
|
|
|
|
static Node *
|
|
adjust_inherited_attrs_mutator(Node *node,
|
|
adjust_inherited_attrs_context *context)
|
|
{
|
|
if (node == NULL)
|
|
return NULL;
|
|
if (IsA(node, Var))
|
|
{
|
|
Var *var = (Var *) copyObject(node);
|
|
|
|
if (var->varlevelsup == 0 &&
|
|
var->varno == context->old_rt_index)
|
|
{
|
|
var->varno = context->new_rt_index;
|
|
var->varnoold = context->new_rt_index;
|
|
if (var->varattno > 0)
|
|
{
|
|
var->varattno = translate_inherited_attnum(var->varattno,
|
|
context);
|
|
var->varoattno = var->varattno;
|
|
}
|
|
else if (var->varattno == 0)
|
|
{
|
|
/*
|
|
* Whole-row Var: we need to insert a coercion step to convert
|
|
* the tuple layout to the parent's rowtype.
|
|
*/
|
|
if (context->old_rel_type != context->new_rel_type)
|
|
{
|
|
ConvertRowtypeExpr *r = makeNode(ConvertRowtypeExpr);
|
|
|
|
r->arg = (Expr *) var;
|
|
r->resulttype = context->old_rel_type;
|
|
r->convertformat = COERCE_IMPLICIT_CAST;
|
|
/* Make sure the Var node has the right type ID, too */
|
|
Assert(var->vartype == context->old_rel_type);
|
|
var->vartype = context->new_rel_type;
|
|
return (Node *) r;
|
|
}
|
|
}
|
|
/* system attributes don't need any translation */
|
|
}
|
|
return (Node *) var;
|
|
}
|
|
if (IsA(node, RangeTblRef))
|
|
{
|
|
RangeTblRef *rtr = (RangeTblRef *) copyObject(node);
|
|
|
|
if (rtr->rtindex == context->old_rt_index)
|
|
rtr->rtindex = context->new_rt_index;
|
|
return (Node *) rtr;
|
|
}
|
|
if (IsA(node, JoinExpr))
|
|
{
|
|
/* Copy the JoinExpr node with correct mutation of subnodes */
|
|
JoinExpr *j;
|
|
|
|
j = (JoinExpr *) expression_tree_mutator(node,
|
|
adjust_inherited_attrs_mutator,
|
|
(void *) context);
|
|
/* now fix JoinExpr's rtindex */
|
|
if (j->rtindex == context->old_rt_index)
|
|
j->rtindex = context->new_rt_index;
|
|
return (Node *) j;
|
|
}
|
|
if (IsA(node, InClauseInfo))
|
|
{
|
|
/* Copy the InClauseInfo node with correct mutation of subnodes */
|
|
InClauseInfo *ininfo;
|
|
|
|
ininfo = (InClauseInfo *) expression_tree_mutator(node,
|
|
adjust_inherited_attrs_mutator,
|
|
(void *) context);
|
|
/* now fix InClauseInfo's relid sets */
|
|
ininfo->lefthand = adjust_relid_set(ininfo->lefthand,
|
|
context->old_rt_index,
|
|
context->new_rt_index);
|
|
ininfo->righthand = adjust_relid_set(ininfo->righthand,
|
|
context->old_rt_index,
|
|
context->new_rt_index);
|
|
return (Node *) ininfo;
|
|
}
|
|
|
|
/*
|
|
* We have to process RestrictInfo nodes specially.
|
|
*/
|
|
if (IsA(node, RestrictInfo))
|
|
{
|
|
RestrictInfo *oldinfo = (RestrictInfo *) node;
|
|
RestrictInfo *newinfo = makeNode(RestrictInfo);
|
|
|
|
/* Copy all flat-copiable fields */
|
|
memcpy(newinfo, oldinfo, sizeof(RestrictInfo));
|
|
|
|
/* Recursively fix the clause itself */
|
|
newinfo->clause = (Expr *)
|
|
adjust_inherited_attrs_mutator((Node *) oldinfo->clause, context);
|
|
|
|
/* and the modified version, if an OR clause */
|
|
newinfo->orclause = (Expr *)
|
|
adjust_inherited_attrs_mutator((Node *) oldinfo->orclause, context);
|
|
|
|
/* adjust relid sets too */
|
|
newinfo->clause_relids = adjust_relid_set(oldinfo->clause_relids,
|
|
context->old_rt_index,
|
|
context->new_rt_index);
|
|
newinfo->left_relids = adjust_relid_set(oldinfo->left_relids,
|
|
context->old_rt_index,
|
|
context->new_rt_index);
|
|
newinfo->right_relids = adjust_relid_set(oldinfo->right_relids,
|
|
context->old_rt_index,
|
|
context->new_rt_index);
|
|
|
|
/*
|
|
* Reset cached derivative fields, since these might need to have
|
|
* different values when considering the child relation.
|
|
*/
|
|
newinfo->eval_cost.startup = -1;
|
|
newinfo->this_selec = -1;
|
|
newinfo->left_pathkey = NIL;
|
|
newinfo->right_pathkey = NIL;
|
|
newinfo->left_mergescansel = -1;
|
|
newinfo->right_mergescansel = -1;
|
|
newinfo->left_bucketsize = -1;
|
|
newinfo->right_bucketsize = -1;
|
|
|
|
return (Node *) newinfo;
|
|
}
|
|
|
|
/*
|
|
* NOTE: we do not need to recurse into sublinks, because they should
|
|
* already have been converted to subplans before we see them.
|
|
*/
|
|
Assert(!IsA(node, SubLink));
|
|
Assert(!IsA(node, Query));
|
|
|
|
/*
|
|
* BUT: although we don't need to recurse into subplans, we do need to
|
|
* make sure that they are copied, not just referenced as
|
|
* expression_tree_mutator will do by default. Otherwise we'll have
|
|
* the same subplan node referenced from each arm of the inheritance
|
|
* APPEND plan, which will cause trouble in the executor. This is a
|
|
* kluge that should go away when we redesign querytrees.
|
|
*/
|
|
if (is_subplan(node))
|
|
{
|
|
SubPlan *subplan;
|
|
|
|
/* Copy the node and process subplan args */
|
|
node = expression_tree_mutator(node, adjust_inherited_attrs_mutator,
|
|
(void *) context);
|
|
/* Make sure we have separate copies of subplan and its rtable */
|
|
subplan = (SubPlan *) node;
|
|
subplan->plan = copyObject(subplan->plan);
|
|
subplan->rtable = copyObject(subplan->rtable);
|
|
return node;
|
|
}
|
|
|
|
return expression_tree_mutator(node, adjust_inherited_attrs_mutator,
|
|
(void *) context);
|
|
}
|
|
|
|
/*
|
|
* Substitute newrelid for oldrelid in a Relid set
|
|
*/
|
|
static Relids
|
|
adjust_relid_set(Relids relids, Index oldrelid, Index newrelid)
|
|
{
|
|
if (bms_is_member(oldrelid, relids))
|
|
{
|
|
/* Ensure we have a modifiable copy */
|
|
relids = bms_copy(relids);
|
|
/* Remove old, add new */
|
|
relids = bms_del_member(relids, oldrelid);
|
|
relids = bms_add_member(relids, newrelid);
|
|
}
|
|
return relids;
|
|
}
|
|
|
|
/*
|
|
* Adjust the targetlist entries of an inherited UPDATE operation
|
|
*
|
|
* The expressions have already been fixed, but we have to make sure that
|
|
* the target resnos match the child table (they may not, in the case of
|
|
* a column that was added after-the-fact by ALTER TABLE). In some cases
|
|
* this can force us to re-order the tlist to preserve resno ordering.
|
|
* (We do all this work in special cases so that preptlist.c is fast for
|
|
* the typical case.)
|
|
*
|
|
* The given tlist has already been through expression_tree_mutator;
|
|
* therefore the TargetEntry nodes are fresh copies that it's okay to
|
|
* scribble on. But the Resdom nodes have not been copied; make new ones
|
|
* if we need to change them!
|
|
*
|
|
* Note that this is not needed for INSERT because INSERT isn't inheritable.
|
|
*/
|
|
static List *
|
|
adjust_inherited_tlist(List *tlist,
|
|
adjust_inherited_attrs_context *context)
|
|
{
|
|
bool changed_it = false;
|
|
ListCell *tl;
|
|
List *new_tlist;
|
|
bool more;
|
|
int attrno;
|
|
|
|
/* Scan tlist and update resnos to match attnums of new_relid */
|
|
foreach(tl, tlist)
|
|
{
|
|
TargetEntry *tle = (TargetEntry *) lfirst(tl);
|
|
Resdom *resdom = tle->resdom;
|
|
|
|
if (resdom->resjunk)
|
|
continue; /* ignore junk items */
|
|
|
|
attrno = translate_inherited_attnum(resdom->resno, context);
|
|
|
|
if (resdom->resno != attrno)
|
|
{
|
|
resdom = (Resdom *) copyObject((Node *) resdom);
|
|
resdom->resno = attrno;
|
|
tle->resdom = resdom;
|
|
changed_it = true;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* If we changed anything, re-sort the tlist by resno, and make sure
|
|
* resjunk entries have resnos above the last real resno. The sort
|
|
* algorithm is a bit stupid, but for such a seldom-taken path, small
|
|
* is probably better than fast.
|
|
*/
|
|
if (!changed_it)
|
|
return tlist;
|
|
|
|
new_tlist = NIL;
|
|
more = true;
|
|
for (attrno = 1; more; attrno++)
|
|
{
|
|
more = false;
|
|
foreach(tl, tlist)
|
|
{
|
|
TargetEntry *tle = (TargetEntry *) lfirst(tl);
|
|
Resdom *resdom = tle->resdom;
|
|
|
|
if (resdom->resjunk)
|
|
continue; /* ignore junk items */
|
|
|
|
if (resdom->resno == attrno)
|
|
new_tlist = lappend(new_tlist, tle);
|
|
else if (resdom->resno > attrno)
|
|
more = true;
|
|
}
|
|
}
|
|
|
|
foreach(tl, tlist)
|
|
{
|
|
TargetEntry *tle = (TargetEntry *) lfirst(tl);
|
|
Resdom *resdom = tle->resdom;
|
|
|
|
if (!resdom->resjunk)
|
|
continue; /* here, ignore non-junk items */
|
|
|
|
if (resdom->resno != attrno)
|
|
{
|
|
resdom = (Resdom *) copyObject((Node *) resdom);
|
|
resdom->resno = attrno;
|
|
tle->resdom = resdom;
|
|
}
|
|
new_tlist = lappend(new_tlist, tle);
|
|
attrno++;
|
|
}
|
|
|
|
return new_tlist;
|
|
}
|