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Postgres FD Implementation
Commit 14022014 authored by Tom Lane's avatar Tom Lane
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Clean up checking of relkind for ALTER TABLE and LOCK TABLE commands. 

Disallow cases like adding constraints to sequences :-(, and eliminate
now-unnecessary search of pg_rewrite to decide if a relation is a view.
parent deb21f0f
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Showing with 39 additions and 91 deletions
src/backend/commands/command.c
View file @ 14022014
......@@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/commands/Attic/command.c,v 1.114 2000/12/22 23:12:05 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/commands/Attic/command.c,v 1.115 2001/01/07 00:05:22 tgl Exp $
*
* NOTES
* The PerformAddAttribute() code, like most of the relation
......@@ -57,8 +57,7 @@
static bool needs_toast_table(Relation rel);
static bool is_viewr(char *relname);
static bool is_view(Relation rel);
static bool is_relation(char *name);
/* --------------------------------
......@@ -302,6 +301,11 @@ AlterTableAddColumn(const char *relationName,
* release until end of transaction.
*/
rel = heap_openr(relationName, AccessExclusiveLock);
if (rel->rd_rel->relkind != RELKIND_RELATION)
elog(ERROR, "ALTER TABLE: relation \"%s\" is not a table",
relationName);
myrelid = RelationGetRelid(rel);
heap_close(rel, NoLock); /* close rel but keep lock! */
......@@ -367,13 +371,6 @@ AlterTableAddColumn(const char *relationName,
elog(ERROR, "ALTER TABLE: relation \"%s\" not found",
relationName);
/*
* XXX is the following check sufficient?
*/
if (((Form_pg_class) GETSTRUCT(reltup))->relkind != RELKIND_RELATION)
elog(ERROR, "ALTER TABLE: relation \"%s\" is not a table",
relationName);
minattnum = ((Form_pg_class) GETSTRUCT(reltup))->relnatts;
maxatts = minattnum + 1;
if (maxatts > MaxHeapAttributeNumber)
......@@ -517,8 +514,9 @@ AlterTableAlterColumn(const char *relationName,
#endif
rel = heap_openr(relationName, AccessExclusiveLock);
if ( rel->rd_rel->relkind == RELKIND_VIEW )
elog(ERROR, "ALTER TABLE: %s is a view", relationName);
if (rel->rd_rel->relkind != RELKIND_RELATION)
elog(ERROR, "ALTER TABLE: relation \"%s\" is not a table",
relationName);
myrelid = RelationGetRelid(rel);
heap_close(rel, NoLock);
......@@ -936,6 +934,11 @@ AlterTableDropColumn(const char *relationName,
* release until end of transaction.
*/
rel = heap_openr(relationName, AccessExclusiveLock);
if (rel->rd_rel->relkind != RELKIND_RELATION)
elog(ERROR, "ALTER TABLE: relation \"%s\" is not a table",
relationName);
myrelid = RelationGetRelid(rel);
heap_close(rel, NoLock); /* close rel but keep lock! */
......@@ -969,15 +972,6 @@ AlterTableDropColumn(const char *relationName,
reltup = heap_copytuple(&classtuple);
ReleaseBuffer(buffer);
/*
* XXX is the following check sufficient?
*/
if (((Form_pg_class) GETSTRUCT(reltup))->relkind != RELKIND_RELATION)
{
elog(ERROR, "ALTER TABLE: relation \"%s\" is not a table",
relationName);
}
attrdesc = heap_openr(AttributeRelationName, RowExclusiveLock);
/*
......@@ -1090,9 +1084,10 @@ AlterTableAddConstraint(char *relationName,
elog(ERROR, "ALTER TABLE: permission denied");
#endif
/* check to see if the table to be constrained is a view. */
if (is_viewr(relationName))
elog(ERROR, "ALTER TABLE: Cannot add constraints to views.");
/* Disallow ADD CONSTRAINT on views, indexes, sequences, etc */
if (! is_relation(relationName))
elog(ERROR, "ALTER TABLE ADD CONSTRAINT: %s is not a table",
relationName);
switch (nodeTag(newConstraint))
{
......@@ -1482,9 +1477,18 @@ AlterTableOwner(const char *relationName, const char *newOwnerName)
elog(ERROR, "ALTER TABLE: relation \"%s\" not found",
relationName);
if (((Form_pg_class) GETSTRUCT(tuple))->relkind != RELKIND_RELATION)
elog(ERROR, "ALTER TABLE: relation \"%s\" is not a table",
relationName);
switch (((Form_pg_class) GETSTRUCT(tuple))->relkind)
{
case RELKIND_RELATION:
case RELKIND_INDEX:
case RELKIND_VIEW:
case RELKIND_SEQUENCE:
/* ok to change owner */
break;
default:
elog(ERROR, "ALTER TABLE: relation \"%s\" is not a table, index, view, or sequence",
relationName);
}
/*
* modify the table's entry and write to the heap
......@@ -1541,6 +1545,11 @@ AlterTableCreateToastTable(const char *relationName, bool silent)
* release until end of transaction.
*/
rel = heap_openr(relationName, AccessExclusiveLock);
if (rel->rd_rel->relkind != RELKIND_RELATION)
elog(ERROR, "ALTER TABLE: relation \"%s\" is not a table",
relationName);
myrelid = RelationGetRelid(rel);
/*
......@@ -1569,19 +1578,8 @@ AlterTableCreateToastTable(const char *relationName, bool silent)
ReleaseBuffer(buffer);
/*
* XXX is the following check sufficient? At least it would
* allow to create TOAST tables for views. But why not - someone
* can insert into a view, so it shouldn't be impossible to hide
* huge data there :-)
*
* Not any more.
* Is it already toasted?
*/
if (((Form_pg_class) GETSTRUCT(reltup))->relkind != RELKIND_RELATION)
{
elog(ERROR, "ALTER TABLE: relation \"%s\" is not a table",
relationName);
}
if (((Form_pg_class) GETSTRUCT(reltup))->reltoastrelid != InvalidOid)
{
if (silent)
......@@ -1781,9 +1779,6 @@ LockTableCommand(LockStmt *lockstmt)
if (rel->rd_rel->relkind != RELKIND_RELATION)
elog(ERROR, "LOCK TABLE: %s is not a table", lockstmt->relname);
if (is_view(rel))
elog(ERROR, "LOCK TABLE: cannot lock a view");
if (lockstmt->mode == AccessShareLock)
aclresult = pg_aclcheck(lockstmt->relname, GetUserId(), ACL_RD);
else
......@@ -1799,60 +1794,13 @@ LockTableCommand(LockStmt *lockstmt)
static bool
is_viewr(char *name)
is_relation(char *name)
{
Relation rel = heap_openr(name, NoLock);
bool retval = is_view(rel);
bool retval = (rel->rd_rel->relkind == RELKIND_RELATION);
heap_close(rel, NoLock);
return retval;
}
static bool
is_view(Relation rel)
{
Relation RewriteRelation;
HeapScanDesc scanDesc;
ScanKeyData scanKeyData;
HeapTuple tuple;
Form_pg_rewrite data;
bool retval = false;
/*
* Open the pg_rewrite relation.
*/
RewriteRelation = heap_openr(RewriteRelationName, RowExclusiveLock);
/*
* Scan the RuleRelation ('pg_rewrite') for all the tuples that has
* the same ev_class as the relation being checked.
*/
ScanKeyEntryInitialize(&scanKeyData,
0,
Anum_pg_rewrite_ev_class,
F_OIDEQ,
ObjectIdGetDatum(rel->rd_id));
scanDesc = heap_beginscan(RewriteRelation,
0, SnapshotNow, 1, &scanKeyData);
while (HeapTupleIsValid(tuple = heap_getnext(scanDesc, 0)))
{
if (tuple->t_data != NULL)
{
data = (Form_pg_rewrite) GETSTRUCT(tuple);
if (data->ev_type == '1')
{
retval = true;
break;
}
}
}
heap_endscan(scanDesc);
heap_close(RewriteRelation, RowExclusiveLock);
return retval;
}
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