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If an index depends on no columns of its table, give it a dependency on the

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whole table instead, to ensure that it goes away when the table is dropped.
Per bug #3723 from Sam Mason.

Backpatch as far as 7.4; AFAICT 7.3 does not have the issue, because it doesn't
have general-purpose expression indexes and so there must be at least one
column referenced by an index.
This commit is contained in:
Tom Lane 2007-11-08 23:23:00 +00:00
parent 5b860028f1
commit 0d05eb671e
1 changed files with 25 additions and 1 deletions
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26
src/backend/catalog/index.c
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@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/catalog/index.c,v 1.274 2006/10/04 00:29:50 momjian Exp $
* $PostgreSQL: pgsql/src/backend/catalog/index.c,v 1.274.2.1 2007/11/08 23:23:00 tgl Exp $
*
*
* INTERFACE ROUTINES
@ -40,6 +40,7 @@
#include "executor/executor.h"
#include "miscadmin.h"
#include "optimizer/clauses.h"
#include "optimizer/var.h"
#include "parser/parse_expr.h"
#include "storage/procarray.h"
#include "storage/smgr.h"
@ -690,6 +691,8 @@ index_create(Oid heapRelationId,
}
else
{
bool have_simple_col = false;
/* Create auto dependencies on simply-referenced columns */
for (i = 0; i < indexInfo->ii_NumIndexAttrs; i++)
{
@ -700,8 +703,29 @@ index_create(Oid heapRelationId,
referenced.objectSubId = indexInfo->ii_KeyAttrNumbers[i];
recordDependencyOn(&myself, &referenced, DEPENDENCY_AUTO);
have_simple_col = true;
}
}
/*
* It's possible for an index to not depend on any columns of
* the table at all, in which case we need to give it a dependency
* on the table as a whole; else it won't get dropped when the
* table is dropped. This edge case is not totally useless;
* for example, a unique index on a constant expression can serve
* to prevent a table from containing more than one row.
*/
if (!have_simple_col &&
!contain_vars_of_level((Node *) indexInfo->ii_Expressions, 0) &&
!contain_vars_of_level((Node *) indexInfo->ii_Predicate, 0))
{
referenced.classId = RelationRelationId;
referenced.objectId = heapRelationId;
referenced.objectSubId = 0;
recordDependencyOn(&myself, &referenced, DEPENDENCY_AUTO);
}
}
/* Store dependency on operator classes */