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-rw-r--r--src/backend/optimizer/prep/prepunion.c168
1 files changed, 135 insertions, 33 deletions
diff --git a/src/backend/optimizer/prep/prepunion.c b/src/backend/optimizer/prep/prepunion.c
index af2bb7e40e5..abc5af7784f 100644
--- a/src/backend/optimizer/prep/prepunion.c
+++ b/src/backend/optimizer/prep/prepunion.c
@@ -14,13 +14,14 @@
*
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/optimizer/prep/prepunion.c,v 1.112 2004/05/30 23:40:29 neilc Exp $
+ * $PostgreSQL: pgsql/src/backend/optimizer/prep/prepunion.c,v 1.113 2004/06/05 01:55:04 tgl Exp $
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
+#include "access/heapam.h"
#include "catalog/pg_type.h"
#include "nodes/makefuncs.h"
#include "optimizer/clauses.h"
@@ -39,8 +40,10 @@ typedef struct
{
Index old_rt_index;
Index new_rt_index;
- Oid old_relid;
- Oid new_relid;
+ TupleDesc old_tupdesc;
+ TupleDesc new_tupdesc;
+ char *old_rel_name;
+ char *new_rel_name;
} adjust_inherited_attrs_context;
static Plan *recurse_set_operations(Node *setOp, Query *parse,
@@ -65,7 +68,8 @@ static bool tlist_same_datatypes(List *tlist, List *colTypes, bool junkOK);
static Node *adjust_inherited_attrs_mutator(Node *node,
adjust_inherited_attrs_context *context);
static Relids adjust_relid_set(Relids relids, Index oldrelid, Index newrelid);
-static List *adjust_inherited_tlist(List *tlist, Oid old_relid, Oid new_relid);
+static List *adjust_inherited_tlist(List *tlist,
+ adjust_inherited_attrs_context *context);
/*
@@ -787,17 +791,17 @@ expand_inherited_rtentry(Query *parse, Index rti, bool dup_parent)
* 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
- * helps ALTER TABLE ADD COLUMN. Unfortunately this isn't nearly enough to
- * make it work transparently; there are other places where things fall down
- * if children and parents don't have the same column numbers for inherited
- * attributes. It'd be better to rip this code out and fix ALTER TABLE...
+ * 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)
@@ -806,10 +810,19 @@ adjust_inherited_attrs(Node *node,
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_relid = old_relid;
- context.new_relid = new_relid;
+ 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.
@@ -829,13 +842,109 @@ adjust_inherited_attrs(Node *node,
if (newnode->commandType == CMD_UPDATE)
newnode->targetList =
adjust_inherited_tlist(newnode->targetList,
- old_relid,
- new_relid);
+ &context);
}
- return (Node *) newnode;
+ result = (Node *) newnode;
}
else
- return adjust_inherited_attrs_mutator(node, &context);
+ 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 */
+}
+
+/*
+ * Translate a whole-row Var to be correct for a child table.
+ *
+ * In general the child will not have a suitable field layout to be used
+ * directly, so we translate the simple whole-row Var into a ROW() construct.
+ */
+static Node *
+generate_whole_row(Var *var,
+ adjust_inherited_attrs_context *context)
+{
+ RowExpr *rowexpr;
+ List *fields = NIL;
+ int oldnatts = context->old_tupdesc->natts;
+ int i;
+
+ for (i = 0; i < oldnatts; i++)
+ {
+ Form_pg_attribute att = context->old_tupdesc->attrs[i];
+ Var *newvar;
+
+ if (att->attisdropped)
+ {
+ /*
+ * can't use atttypid here, but it doesn't really matter
+ * what type the Const claims to be.
+ */
+ newvar = (Var *) makeNullConst(INT4OID);
+ }
+ else
+ newvar = makeVar(context->new_rt_index,
+ translate_inherited_attnum(i + 1, context),
+ att->atttypid,
+ att->atttypmod,
+ 0);
+ fields = lappend(fields, newvar);
+ }
+ rowexpr = makeNode(RowExpr);
+ rowexpr->args = fields;
+ rowexpr->row_typeid = var->vartype; /* report parent's rowtype */
+ rowexpr->row_format = COERCE_IMPLICIT_CAST;
+
+ return (Node *) rowexpr;
}
static Node *
@@ -855,17 +964,16 @@ adjust_inherited_attrs_mutator(Node *node,
var->varnoold = context->new_rt_index;
if (var->varattno > 0)
{
- char *attname;
-
- attname = get_relid_attribute_name(context->old_relid,
- var->varattno);
- var->varattno = get_attnum(context->new_relid, attname);
- if (var->varattno == InvalidAttrNumber)
- elog(ERROR, "attribute \"%s\" of relation \"%s\" does not exist",
- attname, get_rel_name(context->new_relid));
+ var->varattno = translate_inherited_attnum(var->varattno,
+ context);
var->varoattno = var->varattno;
- pfree(attname);
}
+ else if (var->varattno == 0)
+ {
+ /* expand whole-row reference into a ROW() construct */
+ return generate_whole_row(var, context);
+ }
+ /* system attributes don't need any translation */
}
return (Node *) var;
}
@@ -1022,7 +1130,8 @@ adjust_relid_set(Relids relids, Index oldrelid, Index newrelid)
* Note that this is not needed for INSERT because INSERT isn't inheritable.
*/
static List *
-adjust_inherited_tlist(List *tlist, Oid old_relid, Oid new_relid)
+adjust_inherited_tlist(List *tlist,
+ adjust_inherited_attrs_context *context)
{
bool changed_it = false;
ListCell *tl;
@@ -1035,26 +1144,19 @@ adjust_inherited_tlist(List *tlist, Oid old_relid, Oid new_relid)
{
TargetEntry *tle = (TargetEntry *) lfirst(tl);
Resdom *resdom = tle->resdom;
- char *attname;
if (resdom->resjunk)
continue; /* ignore junk items */
- attname = get_relid_attribute_name(old_relid, resdom->resno);
- attrno = get_attnum(new_relid, attname);
- if (attrno == InvalidAttrNumber)
- elog(ERROR, "attribute \"%s\" of relation \"%s\" does not exist",
- attname, get_rel_name(new_relid));
+ attrno = translate_inherited_attnum(resdom->resno, context);
+
if (resdom->resno != attrno)
{
resdom = (Resdom *) copyObject((Node *) resdom);
resdom->resno = attrno;
- resdom->resname = attname;
tle->resdom = resdom;
changed_it = true;
}
- else
- pfree(attname);
}
/*
generated by cgit v1.2.3 (git 2.25.1) at 2025-05-24 14:39:56 +0000