Stored procedure failure

Started by Michal Hlavacover 21 years ago7 messagesgeneral
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#1Michal Hlavac
hlavki@medium13.sk

hello, I have interesting problem...

I have stored procedure, which works good, but only if input is "correct".
Correct input is, when $1 is id, which exists in table...
If I put non exists id, database fall down and restart with this error:
server closed the connection unexpectedly
This probably means the server terminated abnormally
before or while processing the request.
The connection to the server was lost. Attempting reset: Failed.

I think, that problem is in line:
FOR tmp_row IN SELECT v_name FROM c_part_cat WHERE v_path @> my_path
ORDER BY v_path LOOP
because without them it works well...

Version: 7.4.5 and 7.4.3 (both versions have this problem)

thanx, hlavki

source:

/*==============================================================*/
/* Table: c_part_cat */
/*==============================================================*/
create table c_part_cat (
i_part_cat_id integer default nextval('c_part_cat_seq') not null,
c_code varchar(32) not null,
v_name varchar(128) null,
v_path ltree not null,
i_parent_id int4 null,
constraint pk_c_part_cat primary key (i_part_cat_id)
);

/*==============================================================*/
/* Index: index_13 */
/*==============================================================*/
create index index_13 on c_part_cat (
i_parent_id
);

/*==============================================================*/
/* Index: index_22 */
/*==============================================================*/
create unique index index_22 on c_part_cat (
c_code
);

/*==============================================================*/
/* Index: index_4 */
/*==============================================================*/
create index index_4 on c_part_cat using gist (
v_path
);

alter table c_part_cat
add constraint fk_c_part_cat_ref_c_part_cat foreign key (i_parent_id)
references c_part_cat (i_part_cat_id)
on delete restrict on update restrict;

CREATE OR REPLACE FUNCTION "public"."get_part_cat_path" (integer)
RETURNS text AS'
DECLARE
my_path ltree;
result text;
tmp_row RECORD;
first bool;
BEGIN
SELECT v_path INTO my_path FROM c_part_cat WHERE i_part_cat_id = $1;
result := ''''; first := true;
FOR tmp_row IN SELECT v_name FROM c_part_cat WHERE v_path @> my_path
ORDER BY v_path LOOP
IF first THEN
result := tmp_row.v_name;
first := false;
ELSE
result := tmp_row.v_name || ''->'' || result;
END IF;
END LOOP;
RETURN result;
END;
'LANGUAGE 'plpgsql' STABLE CALLED ON NULL INPUT SECURITY INVOKER;

--

[ miso hlavac ][ hlavki@medium13.sk ][ http://www.medium13.sk ]
[ icq:94900232 ][ callto://hlavki ]

#2Michal Hlavac
hlavki@medium13.sk
In reply to: Michal Hlavac (#1)
Re: Stored procedure failure

Michal Hlavac wrote:

hello, I have interesting problem...

I have stored procedure, which works good, but only if input is

"correct".

Correct input is, when $1 is id, which exists in table...
If I put non exists id, database fall down and restart with this error:
server closed the connection unexpectedly
This probably means the server terminated abnormally
before or while processing the request.
The connection to the server was lost. Attempting reset: Failed.

I think, that problem is in line:
FOR tmp_row IN SELECT v_name FROM c_part_cat WHERE v_path @> my_path
ORDER BY v_path LOOP
because without them it works well...

Version: 7.4.5 and 7.4.3 (both versions have this problem)

I am sorry... I've got it... my_path cannot be null... ;)

thanx, hlavki

--

[ miso hlavac ][ hlavki@medium13.sk ][ http://www.medium13.sk ]
[ icq:94900232 ][ callto://hlavki ]

#3Richard Huxton
dev@archonet.com
In reply to: Michal Hlavac (#1)
Re: Stored procedure failure

Michal Hlavac wrote:

hello, I have interesting problem...

I have stored procedure, which works good, but only if input is "correct".
Correct input is, when $1 is id, which exists in table...
If I put non exists id, database fall down and restart with this error:
server closed the connection unexpectedly
This probably means the server terminated abnormally
before or while processing the request.
The connection to the server was lost. Attempting reset: Failed.

I think, that problem is in line:
FOR tmp_row IN SELECT v_name FROM c_part_cat WHERE v_path @> my_path
ORDER BY v_path LOOP
because without them it works well...

CREATE OR REPLACE FUNCTION "public"."get_part_cat_path" (integer)
RETURNS text AS'
DECLARE
my_path ltree;

...

BEGIN
SELECT v_path INTO my_path FROM c_part_cat WHERE i_part_cat_id = $1;
result := ''''; first := true;
FOR tmp_row IN SELECT v_name FROM c_part_cat WHERE v_path @> my_path

I'm guessing a problem with the ltree code. Presumably in handling the
null my_path.

Version: 7.4.5 and 7.4.3 (both versions have this problem)

Looking at the 8.0beta source, the functions (...ltree_isparent) are all
marked strict so they should just return null on a null parameter.

What happens if you set my_path to some non-null but un-matched value
before the problem line?

--
Richard Huxton
Archonet Ltd

#4Michal Hlavac
hlavki@medium13.sk
In reply to: Richard Huxton (#3)
Re: Stored procedure failure

Richard Huxton wrote:

Looking at the 8.0beta source, the functions (...ltree_isparent) are all
marked strict so they should just return null on a null parameter.

What happens if you set my_path to some non-null but un-matched value
before the problem line?

When my_path have non-null value, everything is OK...

I don't understand why one null value would crash the server???

--

[ miso hlavac ][ hlavki@medium13.sk ][ http://www.medium13.sk ]
[ icq:94900232 ][ callto://hlavki ]

#5Richard Huxton
dev@archonet.com
In reply to: Michal Hlavac (#4)
Re: ltree bug handling nulls (was Stored procedure failure)

Michal Hlavac wrote:

Richard Huxton wrote:

Looking at the 8.0beta source, the functions (...ltree_isparent) are
all marked strict so they should just return null on a null parameter.

What happens if you set my_path to some non-null but un-matched value
before the problem line?

When my_path have non-null value, everything is OK...

I don't understand why one null value would crash the server???

Because it attempts to follow a pointer that isn't there.

If you installed from source, can you check contrib/ltree/ltree.sql.in
and check the "isstrict" attribute is set:
CREATE FUNCTION ltree_isparent(ltree,ltree)
RETURNS bool
AS 'MODULE_PATHNAME'
LANGUAGE 'C' WITH (isstrict,iscachable);

If it is, then you'll have to wait for a developer to take an interest,
I'm stumped. Shouldn't take long, but if you wanted to be thorough you
could report a bug via the bugs mailing list or the website.

--
Richard Huxton
Archonet Ltd

#6Tom Lane
tgl@sss.pgh.pa.us
In reply to: Michal Hlavac (#1)
Re: Stored procedure failure

Michal Hlavac <hlavki@medium13.sk> writes:

I have stored procedure, which works good, but only if input is "correct".
Correct input is, when $1 is id, which exists in table...
If I put non exists id, database fall down and restart with this error:
server closed the connection unexpectedly

I can't reproduce a crash here, but perhaps that's because you have not
supplied any sample data...

regards, tom lane

#7Tom Lane
tgl@sss.pgh.pa.us
In reply to: Michal Hlavac (#1)
Re: Stored procedure failure

Michal Hlavac <hlavki@medium13.sk> writes:

Tom Lane wrote:

I can't reproduce a crash here, but perhaps that's because you have not
supplied any sample data...

I attached file with data, where it fails...

Thanks. It turns out the main reason I couldn't reproduce it was
I was testing in CVS tip, where the bug had already been repaired.
I've applied the attached patch to the 7.4 branch to fix it there.

regards, tom lane

Index: gistget.c
===================================================================
RCS file: /cvsroot/pgsql-server/src/backend/access/gist/gistget.c,v
retrieving revision 1.36
diff -c -r1.36 gistget.c
*** gistget.c	4 Aug 2003 02:39:57 -0000	1.36
--- gistget.c	27 Aug 2004 17:44:04 -0000
***************
*** 234,249 ****
  							  key[0].sk_attno,
  							  giststate->tupdesc,
  							  &isNull);
  		if (isNull)
  		{
  			/* XXX eventually should check if SK_ISNULL */
  			return false;
  		}
! 
! /* this code from backend/access/common/indexvalid.c. But why and what???
  		if (key[0].sk_flags & SK_ISNULL)
  			return false;
! */
  		gistdentryinit(giststate, key[0].sk_attno - 1, &de,
  					   datum, r, p, offset,
  					   IndexTupleSize(tuple) - sizeof(IndexTupleData),
--- 234,249 ----
  							  key[0].sk_attno,
  							  giststate->tupdesc,
  							  &isNull);
+ 		/* is the index entry NULL? */
  		if (isNull)
  		{
  			/* XXX eventually should check if SK_ISNULL */
  			return false;
  		}
! 		/* is the compared-to datum NULL? */
  		if (key[0].sk_flags & SK_ISNULL)
  			return false;
! 
  		gistdentryinit(giststate, key[0].sk_attno - 1, &de,
  					   datum, r, p, offset,
  					   IndexTupleSize(tuple) - sizeof(IndexTupleData),