Thread: coalesce in execute crashes backend
Vinod Kurup (vkurup@massmed.org) reports a bug with a severity of 3
The lower the number the more severe it is.
Short Description
coalesce in execute crashes backend
Long Description
When I use a coalesce statement to calculate an expression that is part of a dynamic query, it crashes the backend.
Interestingly,it works if I use constants as arguments to coalesce.
Sample Code
select version();
create function vk_test()
returns integer as '
declare
v_id integer;
begin
v_id := 2;
raise notice ''try a constant.'';
execute ''select '' || coalesce(2,0) || '';'';
raise notice ''that worked'';
raise notice ''now, try a var with the same value.'';
execute ''select '' || coalesce(v_id,0) || '';'';
raise notice ''we never get here'';
return 0;
end;' language 'plpgsql';
select vk_test();
version
-------------------------------------------------------------
PostgreSQL 7.1 on i586-pc-linux-gnu, compiled by GCC 2.95.3
(1 row)
CREATE
psql:junk.sql:24: NOTICE: try a constant.
psql:junk.sql:24: NOTICE: that worked
psql:junk.sql:24: NOTICE: now, try a var with the same value.
psql:junk.sql:24: pqReadData() -- backend closed the channel unexpectedly.
This probably means the backend terminated abnormally
before or while processing the request.
psql:junk.sql:24: connection to server was lost
server.log:
NOTICE: try a constant.
NOTICE: that worked
NOTICE: now, try a var with the same value.
Server process (pid 7516) exited with status 11 at Tue Jun 12 14:32:13 2001
Terminating any active server processes...
NOTICE: Message from PostgreSQL backend:
The Postmaster has informed me that some other backend died abnormally and possibly corrupted shared memory.
I have rolled back the current transaction and am going to terminate your database system connection and exit.
Please reconnect to the database system and repeat your query.
No file was uploaded with this report
pgsql-bugs@postgresql.org writes:
> coalesce in execute crashes backend
Try the attached patch to 7.1.2. I see Jan's already fixed this in
current sources, but not in the 7.1 branch ...
regards, tom lane
*** src/pl/plpgsql/src/pl_exec.c.orig Mon May 7 21:02:03 2001
--- src/pl/plpgsql/src/pl_exec.c Tue Jun 12 21:02:59 2001
***************
*** 3,9 ****
* procedural language
*
* IDENTIFICATION
! * $Header: /home/projects/pgsql/cvsroot/pgsql/src/pl/plpgsql/src/pl_exec.c,v 1.41.2.1 2001/05/08 01:02:03 tgl
Exp$
*
* This software is copyrighted by Jan Wieck - Hamburg.
*
--- 3,9 ----
* procedural language
*
* IDENTIFICATION
! * $Header: /home/projects/pgsql/cvsroot/pgsql/src/pl/plpgsql/src/pl_exec.c,v 1.41.2.2 2001/06/13 01:02:59 tgl
Exp$
*
* This software is copyrighted by Jan Wieck - Hamburg.
*
***************
*** 1922,1930 ****
ObjectIdGetDatum(typeStruct->typelem),
Int32GetDatum(-1)));
- if (!typeStruct->typbyval)
- pfree((void *) query);
-
ReleaseSysCache(typetup);
/*
--- 1922,1927 ----
***************
*** 2037,2045 ****
query,
ObjectIdGetDatum(typeStruct->typelem),
Int32GetDatum(-1)));
-
- if (!typeStruct->typbyval)
- pfree((void *) query);
ReleaseSysCache(typetup);
--- 2034,2039 ----
On Tue, Jun 12, 2001 at 09:06:17PM -0400, Tom Lane wrote: > pgsql-bugs@postgresql.org writes: > > coalesce in execute crashes backend > > Try the attached patch to 7.1.2. I see Jan's already fixed this in > current sources, but not in the 7.1 branch ... > Excellent!! That fixed it. Will this fix then be placed in the next 7.1.x release as well? Thanks, Vinod -- _____________________________ Vinod Kurup, MD email: vkurup@massmed.org phone: 617.277.2012 cell: 617.359.5990 http://www.kurup.com aim: vvkurup
Vinod Kurup <vkurup@massmed.org> writes:
> Will this fix then be placed in the next 7.1.x release as well?
Yes, if there is one.
regards, tom lane