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author
Hiroshi Inoue
committed
Trial implementation of ALTER DROP COLUMN.
They are #ifdef'd. Add -D_DROP_COLUMN_HACK__ compile option to evaluate it.
1 parent 6513946 commit fd9ff86

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8 files changed

+514
-10
lines changed

8 files changed

+514
-10
lines changed

‎src/backend/commands/command.c

Lines changed: 380 additions & 1 deletion
Large diffs are not rendered by default.

‎src/backend/commands/copy.c

Lines changed: 43 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -7,7 +7,7 @@
77
*
88
*
99
* IDENTIFICATION
10-
* $Header: /cvsroot/pgsql/src/backend/commands/copy.c,v 1.101 2000/02/13 18:59:50 momjian Exp $
10+
* $Header: /cvsroot/pgsql/src/backend/commands/copy.c,v 1.102 2000/03/09 05:00:23 inoue Exp $
1111
*
1212
*-------------------------------------------------------------------------
1313
*/
@@ -394,6 +394,9 @@ CopyTo(Relation rel, bool binary, bool oids, FILE *fp, char *delim, char *null_p
394394

395395
int32 attr_count,
396396
i;
397+
#ifdef _DROP_COLUMN_HACK__
398+
bool *valid;
399+
#endif /* _DROP_COLUMN_HACK__ */
397400
Form_pg_attribute *attr;
398401
FmgrInfo *out_functions;
399402
Oid out_func_oid;
@@ -425,8 +428,20 @@ CopyTo(Relation rel, bool binary, bool oids, FILE *fp, char *delim, char *null_p
425428
out_functions = (FmgrInfo *) palloc(attr_count * sizeof(FmgrInfo));
426429
elements = (Oid *) palloc(attr_count * sizeof(Oid));
427430
typmod = (int32 *) palloc(attr_count * sizeof(int32));
431+
#ifdef _DROP_COLUMN_HACK__
432+
valid = (bool *) palloc(attr_count * sizeof(bool));
433+
#endif /* _DROP_COLUMN_HACK__ */
428434
for (i = 0; i < attr_count; i++)
429435
{
436+
#ifdef _DROP_COLUMN_HACK__
437+
if (COLUMN_IS_DROPPED(attr[i]))
438+
{
439+
valid[i] = false;
440+
continue;
441+
}
442+
else
443+
valid[i] = true;
444+
#endif /* _DROP_COLUMN_HACK__ */
430445
out_func_oid = (Oid) GetOutputFunction(attr[i]->atttypid);
431446
fmgr_info(out_func_oid, &out_functions[i]);
432447
elements[i] = GetTypeElement(attr[i]->atttypid);
@@ -466,6 +481,14 @@ CopyTo(Relation rel, bool binary, bool oids, FILE *fp, char *delim, char *null_p
466481
value = heap_getattr(tuple, i + 1, tupDesc, &isnull);
467482
if (!binary)
468483
{
484+
#ifdef _DROP_COLUMN_HACK__
485+
if (!valid[i])
486+
{
487+
if (i == attr_count - 1)
488+
CopySendChar('\n', fp);
489+
continue;
490+
}
491+
#endif /* _DROP_COLUMN_HACK__ */
469492
if (!isnull)
470493
{
471494
string = (char *) (*fmgr_faddr(&out_functions[i]))
@@ -692,6 +715,10 @@ CopyFrom(Relation rel, bool binary, bool oids, FILE *fp, char *delim, char *null
692715
typmod = (int32 *) palloc(attr_count * sizeof(int32));
693716
for (i = 0; i < attr_count; i++)
694717
{
718+
#ifdef _DROP_COLUMN_HACK__
719+
if (COLUMN_IS_DROPPED(attr[i]))
720+
continue;
721+
#endif /* _DROP_COLUMN_HACK__ */
695722
in_func_oid = (Oid) GetInputFunction(attr[i]->atttypid);
696723
fmgr_info(in_func_oid, &in_functions[i]);
697724
elements[i] = GetTypeElement(attr[i]->atttypid);
@@ -718,6 +745,13 @@ CopyFrom(Relation rel, bool binary, bool oids, FILE *fp, char *delim, char *null
718745
{
719746
nulls[i] = ' ';
720747
index_nulls[i] = ' ';
748+
#ifdef _DROP_COLUMN_HACK__
749+
if (COLUMN_IS_DROPPED(attr[i]))
750+
{
751+
byval[i] = 'n';
752+
continue;
753+
}
754+
#endif /* _DROP_COLUMN_HACK__ */
721755
byval[i] = (bool) IsTypeByVal(attr[i]->atttypid);
722756
}
723757

@@ -750,6 +784,14 @@ CopyFrom(Relation rel, bool binary, bool oids, FILE *fp, char *delim, char *null
750784
}
751785
for (i = 0; i < attr_count && !done; i++)
752786
{
787+
#ifdef _DROP_COLUMN_HACK__
788+
if (COLUMN_IS_DROPPED(attr[i]))
789+
{
790+
values[i] = PointerGetDatum(NULL);
791+
nulls[i] = 'n';
792+
continue;
793+
}
794+
#endif /* _DROP_COLUMN_HACK__ */
753795
string = CopyReadAttribute(fp, &isnull, delim, &newline, null_print);
754796
if (isnull)
755797
{

‎src/backend/commands/vacuum.c

Lines changed: 5 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -8,7 +8,7 @@
88
*
99
*
1010
* IDENTIFICATION
11-
* $Header: /cvsroot/pgsql/src/backend/commands/vacuum.c,v 1.142 2000/03/08 23:41:00 tgl Exp $
11+
* $Header: /cvsroot/pgsql/src/backend/commands/vacuum.c,v 1.143 2000/03/09 05:00:23 inoue Exp $
1212
*
1313
*-------------------------------------------------------------------------
1414
*/
@@ -2240,6 +2240,10 @@ vc_attrstats(Relation onerel, VRelStats *vacrelstats, HeapTuple tuple)
22402240
VacAttrStats *stats = &vacattrstats[i];
22412241
bool value_hit = true;
22422242

2243+
#ifdef _DROP_COLUMN_HACK__
2244+
if (COLUMN_IS_DROPPED(stats->attr))
2245+
continue;
2246+
#endif /* _DROP_COLUMN_HACK__ */
22432247
value = heap_getattr(tuple,
22442248
stats->attr->attnum, tupDesc, &isnull);
22452249

‎src/backend/optimizer/prep/preptlist.c

Lines changed: 34 additions & 3 deletions
Original file line numberDiff line numberDiff line change
@@ -15,7 +15,7 @@
1515
* Portions Copyright (c) 1994, Regents of the University of California
1616
*
1717
* IDENTIFICATION
18-
* $Header: /cvsroot/pgsql/src/backend/optimizer/prep/preptlist.c,v 1.34 2000/01/26 05:56:39 momjian Exp $
18+
* $Header: /cvsroot/pgsql/src/backend/optimizer/prep/preptlist.c,v 1.35 2000/03/09 05:00:24 inoue Exp $
1919
*
2020
*-------------------------------------------------------------------------
2121
*/
@@ -189,10 +189,20 @@ expand_targetlist(List *tlist, int command_type,
189189
{
190190
case CMD_INSERT:
191191
{
192+
#ifdef _DROP_COLUMN_HACK__
193+
Datum typedefault;
194+
#else
192195
Datum typedefault = get_typdefault(atttype);
196+
#endif /* _DROP_COLUMN_HACK__ */
193197
int typlen;
194198
Const *temp_const;
195199

200+
#ifdef _DROP_COLUMN_HACK__
201+
if (COLUMN_IS_DROPPED(att_tup))
202+
typedefault = PointerGetDatum(NULL);
203+
else
204+
typedefault = get_typdefault(atttype);
205+
#endif /* _DROP_COLUMN_HACK__ */
196206
if (typedefault == PointerGetDatum(NULL))
197207
typlen = 0;
198208
else
@@ -230,17 +240,38 @@ expand_targetlist(List *tlist, int command_type,
230240
{
231241
Var *temp_var;
232242

243+
#ifdef _DROP_COLUMN_HACK__
244+
Node *temp_node = (Node *) NULL;
245+
if (COLUMN_IS_DROPPED(att_tup))
246+
{
247+
temp_node = (Node *)makeConst(atttype, 0,
248+
PointerGetDatum(NULL),
249+
true,
250+
false,
251+
false, /* not a set */
252+
false);
253+
}
254+
else
255+
#endif /* _DROP_COLUMN_HACK__ */
233256
temp_var = makeVar(result_relation, attrno, atttype,
234257
atttypmod, 0);
258+
#ifdef _DROP_COLUMN_HACK__
259+
if (!temp_node)
260+
temp_node = (Node *) temp_var;
261+
#endif /* _DROP_COLUMN_HACK__ */
235262

236263
new_tle = makeTargetEntry(makeResdom(attrno,
237264
atttype,
238265
atttypmod,
239266
pstrdup(attrname),
240267
0,
241268
(Oid) 0,
242-
false),
243-
(Node *) temp_var);
269+
false),
270+
#ifdef _DROP_COLUMN_HACK__
271+
temp_node);
272+
#else
273+
(Node *) temp_var);
274+
#endif /* _DROP_COLUMN_HACK__ */
244275
break;
245276
}
246277
default:

‎src/backend/parser/parse_relation.c

Lines changed: 9 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -8,7 +8,7 @@
88
*
99
*
1010
* IDENTIFICATION
11-
* $Header: /cvsroot/pgsql/src/backend/parser/parse_relation.c,v 1.35 2000/02/15 03:37:47 thomas Exp $
11+
* $Header: /cvsroot/pgsql/src/backend/parser/parse_relation.c,v 1.36 2000/03/09 05:00:24 inoue Exp $
1212
*
1313
*-------------------------------------------------------------------------
1414
*/
@@ -359,6 +359,10 @@ expandTable(ParseState *pstate, char *refname, bool getaliases)
359359
{
360360
char *attrname;
361361

362+
#ifdef _DROP_COLUMN_HACK__
363+
if (COLUMN_IS_DROPPED(rel->rd_att->attrs[varattno]))
364+
continue;
365+
#endif /* _DROP_COLUMN_HACK__ */
362366
attrname = pstrdup(NameStr(rel->rd_att->attrs[varattno]->attname));
363367
attr->attrs = lappend(attr->attrs, makeString(attrname));
364368
}
@@ -404,6 +408,10 @@ expandAll(ParseState *pstate, char *relname, Attr *ref, int *this_resno)
404408
Var *varnode;
405409
TargetEntry *te = makeNode(TargetEntry);
406410

411+
#ifdef _DROP_COLUMN_HACK__
412+
if (COLUMN_IS_DROPPED(rel->rd_att->attrs[varattno]))
413+
continue;
414+
#endif /* _DROP_COLUMN_HACK__ */
407415
attrname = pstrdup(NameStr(rel->rd_att->attrs[varattno]->attname));
408416

409417
/* varattno is zero-based, so check that length() is always greater */

‎src/backend/parser/parse_target.c

Lines changed: 7 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -8,7 +8,7 @@
88
*
99
*
1010
* IDENTIFICATION
11-
* $Header: /cvsroot/pgsql/src/backend/parser/parse_target.c,v 1.55 2000/02/15 03:37:47 thomas Exp $
11+
* $Header: /cvsroot/pgsql/src/backend/parser/parse_target.c,v 1.56 2000/03/09 05:00:24 inoue Exp $
1212
*
1313
*-------------------------------------------------------------------------
1414
*/
@@ -355,6 +355,12 @@ checkInsertTargets(ParseState *pstate, List *cols, List **attrnos)
355355
{
356356
Ident *id = makeNode(Ident);
357357

358+
#ifdef _DROP_COLUMN_HACK__
359+
if (COLUMN_IS_DROPPED(attr[i]))
360+
{
361+
continue;
362+
}
363+
#endif /* _DROP_COLUMN_HACK__ */
358364
id->name = palloc(NAMEDATALEN);
359365
StrNCpy(id->name, NameStr(attr[i]->attname), NAMEDATALEN);
360366
id->indirection = NIL;

‎src/backend/utils/cache/relcache.c

Lines changed: 21 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -8,7 +8,7 @@
88
*
99
*
1010
* IDENTIFICATION
11-
* $Header: /cvsroot/pgsql/src/backend/utils/cache/relcache.c,v 1.91 2000/02/27 12:02:32 wieck Exp $
11+
* $Header: /cvsroot/pgsql/src/backend/utils/cache/relcache.c,v 1.92 2000/03/09 05:00:25 inoue Exp $
1212
*
1313
*-------------------------------------------------------------------------
1414
*/
@@ -568,19 +568,35 @@ build_tupdesc_ind(RelationBuildDescInfo buildinfo,
568568
AttrDefault *attrdef = NULL;
569569
int ndef = 0;
570570
int i;
571+
#ifdef _DROP_COLUMN_HACK__
572+
bool columnDropped;
573+
#endif /* _DROP_COLUMN_HACK__ */
571574

572575
constr->has_not_null = false;
573576

574577
attrel = heap_openr(AttributeRelationName, AccessShareLock);
575578

576579
for (i = 1; i <= relation->rd_rel->relnatts; i++)
577580
{
581+
#ifdef _DROP_COLUMN_HACK__
582+
columnDropped = false;
583+
#endif /* _DROP_COLUMN_HACK__ */
578584
atttup = (HeapTuple) AttributeRelidNumIndexScan(attrel,
579585
RelationGetRelid(relation), i);
580586

581587
if (!HeapTupleIsValid(atttup))
588+
#ifdef _DROP_COLUMN_HACK__
589+
{
590+
atttup = (HeapTuple) AttributeRelidNumIndexScan(attrel,
591+
RelationGetRelid(relation), DROPPED_COLUMN_INDEX(i));
592+
if (!HeapTupleIsValid(atttup))
593+
#endif /* _DROP_COLUMN_HACK__ */
582594
elog(ERROR, "cannot find attribute %d of relation %s", i,
583595
RelationGetRelationName(relation));
596+
#ifdef _DROP_COLUMN_HACK__
597+
columnDropped = true;
598+
}
599+
#endif /* _DROP_COLUMN_HACK__ */
584600
attp = (Form_pg_attribute) GETSTRUCT(atttup);
585601

586602
relation->rd_att->attrs[i - 1] =
@@ -590,6 +606,10 @@ build_tupdesc_ind(RelationBuildDescInfo buildinfo,
590606
(char *) attp,
591607
ATTRIBUTE_TUPLE_SIZE);
592608

609+
#ifdef _DROP_COLUMN_HACK__
610+
if (columnDropped)
611+
continue;
612+
#endif /* _DROP_COLUMN_HACK__ */
593613
/* Update if this attribute have a constraint */
594614
if (attp->attnotnull)
595615
constr->has_not_null = true;

‎src/include/catalog/pg_attribute.h

Lines changed: 15 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -8,7 +8,7 @@
88
* Portions Copyright (c) 1996-2000, PostgreSQL, Inc
99
* Portions Copyright (c) 1994, Regents of the University of California
1010
*
11-
* $Id: pg_attribute.h,v 1.53 2000/01/26 05:57:57 momjian Exp $
11+
* $Id: pg_attribute.h,v 1.54 2000/03/09 05:00:26 inoue Exp $
1212
*
1313
* NOTES
1414
* the genbki.sh script reads this file and generates .bki
@@ -178,6 +178,20 @@ typedef FormData_pg_attribute *Form_pg_attribute;
178178
#define Anum_pg_attribute_atthasdef 15
179179

180180

181+
#ifdef _DROP_COLUMN_HACK__
182+
/*
183+
* CONSTANT and MACROS for DROP COLUMN implementation
184+
*/
185+
#define DROP_COLUMN_OFFSET -20
186+
#define COLUMN_IS_DROPPED(attribute) ((attribute)->attnum <= DROP_COLUMN_OFFSET)
187+
#define DROPPED_COLUMN_INDEX(attidx) (DROP_COLUMN_OFFSET - attidx)
188+
#define ATTRIBUTE_DROP_COLUMN(attribute) \
189+
Assert((attribute)->attnum > 0); \
190+
(attribute)->attnum = DROPPED_COLUMN_INDEX((attribute)->attnum); \
191+
(attribute)->atttypid = (Oid) -1; \
192+
(attribute)->attnotnull = false; \
193+
(attribute)->atthasdef = false;
194+
#endif /* _DROP_COLUMN_HACK__ */
181195
/* ----------------
182196
* SCHEMA_ macros for declaring hardcoded tuple descriptors.
183197
* these are used in utils/cache/relcache.c

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