Обсуждение: Stored procedure failure

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Stored procedure failure

От
Michal Hlavac
Дата:
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 ]

Re: Stored procedure failure

От
Richard Huxton
Дата:
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

Re: Stored procedure failure

От
Michal Hlavac
Дата:
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 ]

Re: Stored procedure failure

От
Michal Hlavac
Дата:
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 ]

Re: ltree bug handling nulls (was Stored procedure failure)

От
Richard Huxton
Дата:
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

Re: Stored procedure failure

От
Tom Lane
Дата:
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

Re: Stored procedure failure

От
Tom Lane
Дата:
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),