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Commits from this thread:
2019-10-10 93765bd956 f224c7c11e Fix table rewrites that include a column without a default.
* BUG #16038: Alter table - SegFault
@ 2019-10-04 13:29 PG Bug reporting form <noreply@postgresql.org>
2019-10-04 14:43 ` Re: BUG #16038: Alter table - SegFault Alvaro Herrera <alvherre@2ndquadrant.com>
0 siblings, 1 reply; 4+ messages in thread
From: PG Bug reporting form @ 2019-10-04 13:29 UTC (permalink / raw)
To: pgsql-bugs@lists.postgresql.org; +Cc: deathlock13@gmail.com
The following bug has been logged on the website:
Bug reference: 16038
Logged by: death lock
Email address: deathlock13@gmail.com
PostgreSQL version: 12.0
Operating system: WinXP (VisualStudio 2013) , Debian11 gcc9
Description:
create schema if not exists test ;
drop table test.testa;
CREATE TABLE test.testa (
code character varying(2) NOT NULL,
namez character varying(255) NOT NULL,
descr character varying(1024),
wersja numeric(1,0),
modt timestamp without time zone,
crtt timestamp without time zone,
crt integer,
mod integer,
-- ida numeric(10,0) DEFAULT nextval(('test.sq_testa'::text)::regclass)
NOT NULL,
-- fk_tmp character varying(20),
CONSTRAINT test_pk PRIMARY KEY (code)
);
INSERT INTO test.testa VALUES ('0', 'AA', NULL, NULL, '2018-02-19
09:40:38.776875', '2008-05-20 10:06:28.171', 1001, 1001 /*, 1, 'DUMMYA'
*/);
-- INSERT INTO test.testa VALUES ('1', 'BB', NULL, NULL, '2018-02-19
09:40:38.776875', '2008-05-20 10:06:28.171', 1001, 1001 /*, 2, 'DUMMYB'
*/);
drop sequence if exists test.sq_testb;
create SEQUENCE test.sq_testb;
alter table test.testa
add column idb numeric(10,0) NOT NULL DEFAULT nextval('test.sq_testb'),
add column fk_tmpb varchar(20);
server process (PID 21884) was terminated by signal 11: Segmentation fault
- empty table - alter goes ok , split alter into 2 add col - works too
^ permalink raw reply [nested|flat] 4+ messages in thread
* Re: BUG #16038: Alter table - SegFault
2019-10-04 13:29 BUG #16038: Alter table - SegFault PG Bug reporting form <noreply@postgresql.org>
@ 2019-10-04 14:43 ` Alvaro Herrera <alvherre@2ndquadrant.com>
2019-10-04 15:26 ` Re: BUG #16038: Alter table - SegFault Andres Freund <andres@anarazel.de>
0 siblings, 1 reply; 4+ messages in thread
From: Alvaro Herrera @ 2019-10-04 14:43 UTC (permalink / raw)
To: deathlock13@gmail.com, pgsql-bugs@lists.postgresql.org, Andres Freund <andres@anarazel.de>
On 2019-Oct-04, PG Bug reporting form wrote:
> alter table test.testa
> add column idb numeric(10,0) NOT NULL DEFAULT nextval('test.sq_testb'),
> add column fk_tmpb varchar(20);
>
> server process (PID 21884) was terminated by signal 11: Segmentation fault
> - empty table - alter goes ok , split alter into 2 add col - works too
Hmm, confirmed, here's the stack trace:
#0 0x0000561459590e9f in heap_compute_data_size (tupleDesc=tupleDesc@entry=0x7faa37b16618,
values=values@entry=0x56145b26ba30, isnull=isnull@entry=0x56145b26ba80)
at /pgsql/source/REL_12_STABLE/src/backend/access/common/heaptuple.c:138
#1 0x000056145959232b in heap_form_tuple (tupleDescriptor=0x7faa37b16618, values=0x56145b26ba30,
isnull=0x56145b26ba80) at /pgsql/source/REL_12_STABLE/src/backend/access/common/heaptuple.c:1061
#2 0x000056145975f881 in tts_buffer_heap_materialize (slot=0x56145b26b9c0)
at /pgsql/source/REL_12_STABLE/src/backend/executor/execTuples.c:713
#3 0x0000561459761083 in ExecFetchSlotHeapTuple (slot=0x56145b26b9c0, materialize=<optimized out>,
shouldFree=0x7ffffc491bbf) at /pgsql/source/REL_12_STABLE/src/backend/executor/execTuples.c:1618
#4 0x00005614595e09c4 in heapam_tuple_insert (relation=0x7faa37b159e0, slot=0x56145b26b9c0, cid=8,
options=2, bistate=0x56145b26bd68)
at /pgsql/source/REL_12_STABLE/src/backend/access/heap/heapam_handler.c:250
#5 0x0000561459715614 in table_tuple_insert (bistate=0x56145b26bd68, options=2, cid=8,
slot=0x56145b26b9c0, rel=0x7faa37b159e0)
at /pgsql/source/REL_12_STABLE/src/include/access/tableam.h:1126
#6 ATRewriteTable (tab=tab@entry=0x56145b25b5d8, OIDNewHeap=OIDNewHeap@entry=16396,
lockmode=lockmode@entry=8) at /pgsql/source/REL_12_STABLE/src/backend/commands/tablecmds.c:5039
#7 0x000056145972a9b8 in ATRewriteTables (lockmode=8, wqueue=0x7ffffc491d08,
parsetree=0x56145b24d7c0) at /pgsql/source/REL_12_STABLE/src/backend/commands/tablecmds.c:4641
#8 ATController (parsetree=parsetree@entry=0x56145b24d7c0, rel=<optimized out>,
cmds=<optimized out>, recurse=<optimized out>, lockmode=lockmode@entry=8)
at /pgsql/source/REL_12_STABLE/src/backend/commands/tablecmds.c:3848
--
Álvaro Herrera https://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
^ permalink raw reply [nested|flat] 4+ messages in thread
* Re: BUG #16038: Alter table - SegFault
2019-10-04 13:29 BUG #16038: Alter table - SegFault PG Bug reporting form <noreply@postgresql.org>
2019-10-04 14:43 ` Re: BUG #16038: Alter table - SegFault Alvaro Herrera <alvherre@2ndquadrant.com>
@ 2019-10-04 15:26 ` Andres Freund <andres@anarazel.de>
2019-10-10 05:21 ` Re: BUG #16038: Alter table - SegFault Andres Freund <andres@anarazel.de>
0 siblings, 1 reply; 4+ messages in thread
From: Andres Freund @ 2019-10-04 15:26 UTC (permalink / raw)
To: Alvaro Herrera <alvherre@2ndquadrant.com>; +Cc: deathlock13@gmail.com; pgsql-bugs@lists.postgresql.org
Hi,
On 2019-10-04 11:43:52 -0300, Alvaro Herrera wrote:
> On 2019-Oct-04, PG Bug reporting form wrote:
>
> > alter table test.testa
> > add column idb numeric(10,0) NOT NULL DEFAULT nextval('test.sq_testb'),
> > add column fk_tmpb varchar(20);
> >
> > server process (PID 21884) was terminated by signal 11: Segmentation fault
> > - empty table - alter goes ok , split alter into 2 add col - works too
>
> Hmm, confirmed, here's the stack trace:
The trailing attributes in the new slot in AtRewriteTable() aren't
necessarily set to isnull=true. So to trigger the problem, one needs a
rewrite triggered by *another* column (otherwise we'll not hit this
path), combined with a new column that doesn't have a default value. I
think that's probably my bug.
This seems to fix the problem:
inline patch 1: w/src/backend/commands/tablecmds.c (+8/-0 lines) download inline-1.patch
diff --git i/src/backend/commands/tablecmds.c w/src/backend/commands/tablecmds.c
index 05593f33162..6f72b08a87d 100644
--- i/src/backend/commands/tablecmds.c
+++ w/src/backend/commands/tablecmds.c
@@ -4890,6 +4890,14 @@ ATRewriteTable(AlteredTableInfo *tab, Oid OIDNewHeap, LOCKMODE lockmode)
table_slot_callbacks(oldrel));
newslot = MakeSingleTupleTableSlot(newTupDesc,
table_slot_callbacks(newrel));
+
+ /*
+ * Set all columns in the new slot to NULL initially, to ensure
+ * columns added as part of the rewrite are initialized to
+ * NULL. That's necessary as tab->newvals will not contain an
+ * expression for columns with a NULL default.
+ */
+ ExecStoreAllNullTuple(newslot);
}
else
{
* Re: BUG #16038: Alter table - SegFault
2019-10-04 13:29 BUG #16038: Alter table - SegFault PG Bug reporting form <noreply@postgresql.org>
2019-10-04 14:43 ` Re: BUG #16038: Alter table - SegFault Alvaro Herrera <alvherre@2ndquadrant.com>
2019-10-04 15:26 ` Re: BUG #16038: Alter table - SegFault Andres Freund <andres@anarazel.de>
@ 2019-10-10 05:21 ` Andres Freund <andres@anarazel.de>
0 siblings, 0 replies; 4+ messages in thread
From: Andres Freund @ 2019-10-10 05:21 UTC (permalink / raw)
To: Alvaro Herrera <alvherre@2ndquadrant.com>; +Cc: deathlock13@gmail.com; pgsql-bugs@lists.postgresql.org
Hi,
On 2019-10-04 08:26:24 -0700, Andres Freund wrote:
> On 2019-10-04 11:43:52 -0300, Alvaro Herrera wrote:
> > On 2019-Oct-04, PG Bug reporting form wrote:
> >
> > > alter table test.testa
> > > add column idb numeric(10,0) NOT NULL DEFAULT nextval('test.sq_testb'),
> > > add column fk_tmpb varchar(20);
> > >
> > > server process (PID 21884) was terminated by signal 11: Segmentation fault
> > > - empty table - alter goes ok , split alter into 2 add col - works too
Thanks for the bug report! I've pushed a fix, which will be included in
the next minor release. If you need a workaround until then, you can
avoid the crash by only adding one column add a time.
> > Hmm, confirmed, here's the stack trace:
>
> The trailing attributes in the new slot in AtRewriteTable() aren't
> necessarily set to isnull=true. So to trigger the problem, one needs a
> rewrite triggered by *another* column (otherwise we'll not hit this
> path), combined with a new column that doesn't have a default value. I
> think that's probably my bug.
>
> This seems to fix the problem:
>
> diff --git i/src/backend/commands/tablecmds.c w/src/backend/commands/tablecmds.c
> index 05593f33162..6f72b08a87d 100644
> --- i/src/backend/commands/tablecmds.c
> +++ w/src/backend/commands/tablecmds.c
> @@ -4890,6 +4890,14 @@ ATRewriteTable(AlteredTableInfo *tab, Oid OIDNewHeap, LOCKMODE lockmode)
> table_slot_callbacks(oldrel));
> newslot = MakeSingleTupleTableSlot(newTupDesc,
> table_slot_callbacks(newrel));
> +
> + /*
> + * Set all columns in the new slot to NULL initially, to ensure
> + * columns added as part of the rewrite are initialized to
> + * NULL. That's necessary as tab->newvals will not contain an
> + * expression for columns with a NULL default.
> + */
> + ExecStoreAllNullTuple(newslot);
> }
Pushed, after adding some tests.
Greetings,
Andres Freund
^ permalink raw reply [nested|flat] 4+ messages in thread
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2019-10-04 13:29 BUG #16038: Alter table - SegFault PG Bug reporting form <noreply@postgresql.org>
2019-10-04 14:43 ` Alvaro Herrera <alvherre@2ndquadrant.com>
2019-10-04 15:26 ` Andres Freund <andres@anarazel.de>
2019-10-10 05:21 ` Andres Freund <andres@anarazel.de>
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