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Apply fixes for problems with dropped columns whose types have also been

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dropped.  Add regression test, too.
This commit is contained in:
Tom Lane 2003-05-12 00:17:34 +00:00
parent 016e059fcf
commit 3ffaf20461
4 changed files with 147 additions and 25 deletions
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49
src/backend/catalog/heap.c
View File

@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/catalog/heap.c,v 1.232.2.1 2002/12/16 18:39:56 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/catalog/heap.c,v 1.232.2.2 2003/05/12 00:17:33 tgl Exp $
*
*
* INTERFACE ROUTINES
@ -75,7 +75,7 @@ static void StoreAttrDefault(Relation rel, AttrNumber attnum, char *adbin);
static void StoreRelCheck(Relation rel, char *ccname, char *ccbin);
static void StoreConstraints(Relation rel, TupleDesc tupdesc);
static void SetRelationNumChecks(Relation rel, int numchecks);
static void RemoveStatistics(Relation rel);
static void RemoveStatistics(Relation rel, AttrNumber attnum);
/* ----------------------------------------------------------------
@ -911,8 +911,9 @@ DeleteAttributeTuples(Oid relid)
* RemoveAttributeById
*
* This is the guts of ALTER TABLE DROP COLUMN: actually mark the attribute
* deleted in pg_attribute. (Everything else needed, such as getting rid
* of any pg_attrdef entry, is handled by dependency.c.)
* deleted in pg_attribute. We also remove pg_statistic entries for it.
* (Everything else needed, such as getting rid of any pg_attrdef entry,
* is handled by dependency.c.)
*/
void
RemoveAttributeById(Oid relid, AttrNumber attnum)
@ -946,6 +947,16 @@ RemoveAttributeById(Oid relid, AttrNumber attnum)
/* Mark the attribute as dropped */
attStruct->attisdropped = true;
/*
* Set the type OID to invalid. A dropped attribute's type link cannot
* be relied on (once the attribute is dropped, the type might be too).
* Fortunately we do not need the type row --- the only really essential
* information is the type's typlen and typalign, which are preserved in
* the attribute's attlen and attalign. We set atttypid to zero here
* as a means of catching code that incorrectly expects it to be valid.
*/
attStruct->atttypid = InvalidOid;
/* Remove any NOT NULL constraint the column may have */
attStruct->attnotnull = false;
@ -969,6 +980,8 @@ RemoveAttributeById(Oid relid, AttrNumber attnum)
heap_close(attr_rel, RowExclusiveLock);
RemoveStatistics(rel, attnum);
relation_close(rel, NoLock);
}
@ -1143,7 +1156,7 @@ heap_drop_with_catalog(Oid rid)
/*
* delete statistics
*/
RemoveStatistics(rel);
RemoveStatistics(rel, 0);
/*
* delete attribute tuples
@ -1817,27 +1830,45 @@ RemoveRelConstraints(Relation rel, const char *constrName,
}
/*
* RemoveStatistics --- remove entries in pg_statistic for a rel or column
*
* If attnum is zero, remove all entries for rel; else remove only the one
* for that column.
*/
static void
RemoveStatistics(Relation rel)
RemoveStatistics(Relation rel, AttrNumber attnum)
{
Relation pgstatistic;
SysScanDesc scan;
ScanKeyData key;
ScanKeyData key[2];
int nkeys;
HeapTuple tuple;
pgstatistic = heap_openr(StatisticRelationName, RowExclusiveLock);
ScanKeyEntryInitialize(&key, 0x0,
ScanKeyEntryInitialize(&key[0], 0x0,
Anum_pg_statistic_starelid, F_OIDEQ,
ObjectIdGetDatum(RelationGetRelid(rel)));
if (attnum == 0)
nkeys = 1;
else
{
ScanKeyEntryInitialize(&key[1], 0x0,
Anum_pg_statistic_staattnum, F_INT2EQ,
Int16GetDatum(attnum));
nkeys = 2;
}
scan = systable_beginscan(pgstatistic, StatisticRelidAttnumIndex, true,
SnapshotNow, 1, &key);
SnapshotNow, nkeys, key);
while (HeapTupleIsValid(tuple = systable_getnext(scan)))
simple_heap_delete(pgstatistic, &tuple->t_self);
systable_endscan(scan);
heap_close(pgstatistic, RowExclusiveLock);
}

64
src/backend/optimizer/prep/preptlist.c
View File

@ -15,7 +15,7 @@
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/optimizer/prep/preptlist.c,v 1.57 2002/09/18 21:35:21 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/optimizer/prep/preptlist.c,v 1.57.2.1 2003/05/12 00:17:34 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -171,6 +171,15 @@ expand_targetlist(List *tlist, int command_type,
* the attribute, so that it gets copied to the new tuple. But
* generate a NULL for dropped columns (we want to drop any
* old values).
*
* When generating a NULL constant for a dropped column, we label
* it INT4 (any other guaranteed-to-exist datatype would do as
* well). We can't label it with the dropped column's datatype
* since that might not exist anymore. It does not really
* matter what we claim the type is, since NULL is NULL --- its
* representation is datatype-independent. This could perhaps
* confuse code comparing the finished plan to the target
* relation, however.
*/
Oid atttype = att_tup->atttypid;
int32 atttypmod = att_tup->atttypmod;
@ -179,34 +188,57 @@ expand_targetlist(List *tlist, int command_type,
switch (command_type)
{
case CMD_INSERT:
new_expr = (Node *) makeConst(atttype,
att_tup->attlen,
(Datum) 0,
true, /* isnull */
att_tup->attbyval,
false, /* not a set */
false);
if (!att_tup->attisdropped)
new_expr = coerce_type_constraints(new_expr,
atttype,
COERCE_IMPLICIT_CAST);
break;
case CMD_UPDATE:
/* Insert NULLs for dropped columns */
if (att_tup->attisdropped)
{
new_expr = (Node *) makeConst(atttype,
att_tup->attlen,
(Datum) 0,
true, /* isnull */
true, /* isnull */
att_tup->attbyval,
false, /* not a set */
false);
new_expr = coerce_type_constraints(new_expr,
atttype,
COERCE_IMPLICIT_CAST);
}
else
{
/* Insert NULL for dropped column */
new_expr = (Node *) makeConst(INT4OID,
sizeof(int32),
(Datum) 0,
true, /* isnull */
true, /* byval */
false, /* not a set */
false);
/* label resdom with INT4, too */
atttype = INT4OID;
atttypmod = -1;
}
break;
case CMD_UPDATE:
if (!att_tup->attisdropped)
{
new_expr = (Node *) makeVar(result_relation,
attrno,
atttype,
atttypmod,
0);
}
else
{
/* Insert NULL for dropped column */
new_expr = (Node *) makeConst(INT4OID,
sizeof(int32),
(Datum) 0,
true, /* isnull */
true, /* byval */
false, /* not a set */
false);
/* label resdom with INT4, too */
atttype = INT4OID;
atttypmod = -1;
}
break;
default:
elog(ERROR, "expand_targetlist: unexpected command_type");

41
src/test/regress/expected/alter_table.out
View File

@ -1166,3 +1166,44 @@ order by relname, attnum;
drop table p1, p2 cascade;
NOTICE: Drop cascades to table c1
NOTICE: Drop cascades to table gc1
-- test that operations with a dropped column do not try to reference
-- its datatype
create domain mytype as text;
create temp table foo (f1 text, f2 mytype, f3 text);
insert into foo values('aa','bb','cc');
select * from foo;
f1 | f2 | f3
----+----+----
aa | bb | cc
(1 row)
drop domain mytype cascade;
NOTICE: Drop cascades to table foo column f2
select * from foo;
f1 | f3
----+----
aa | cc
(1 row)
insert into foo values('qq','rr');
select * from foo;
f1 | f3
----+----
aa | cc
qq | rr
(2 rows)
update foo set f3 = 'zz';
select * from foo;
f1 | f3
----+----
aa | zz
qq | zz
(2 rows)
select f3,max(f1) from foo group by f3;
f3 | max
----+-----
zz | qq
(1 row)

18
src/test/regress/sql/alter_table.sql
View File

@ -845,3 +845,21 @@ where relname in ('p1','p2','c1','gc1') and attnum > 0 and not attisdropped
order by relname, attnum;
drop table p1, p2 cascade;
-- test that operations with a dropped column do not try to reference
-- its datatype
create domain mytype as text;
create temp table foo (f1 text, f2 mytype, f3 text);
insert into foo values('aa','bb','cc');
select * from foo;
drop domain mytype cascade;
select * from foo;
insert into foo values('qq','rr');
select * from foo;
update foo set f3 = 'zz';
select * from foo;
select f3,max(f1) from foo group by f3;