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Thread: More details on Database corruption

More details on Database corruption

From
George Kousi
Date:
Hi,

I managed to recreate a simple example that's crashing postgres.  I am
running on a DEC Alpha with Digital Unix Version 4.0d and Postgres
3.2.   I tried this example several times, on several databases and it
crashes every time.  We also re-built Postgres and still did not work.
Here's the example. Can anybody please help?

Thank you...
George K.
/***** INPUT FILE: hist.sql *******/

drop table tasks;
CREATE TABLE tasks (
task  INT4 NOT NULL,
job  INT4 NOT NULL,
Version1 CHAR(6) DEFAULT '',
Version2 CHAR(6) DEFAULT '',
Version3 CHAR(6) DEFAULT '',
Version4 CHAR(6) DEFAULT '',
Version5 CHAR(6) DEFAULT ''
);

INSERT INTO tasks (task, job) VALUES (1, 1);
select * from tasks;
update tasks set version1='1',version2='2', version3='3', version4='4',
version5='5' where task=1;
select * from tasks;


/****** OUTPUT FROM pgsql **********/
test=> \i hist.sql
drop table tasks;
DROP
CREATE TABLE tasks (
task            INT4 NOT NULL,
job             INT4 NOT NULL,
Version1        CHAR(6) DEFAULT '',
Version2        CHAR(6) DEFAULT '',
Version3        CHAR(6) DEFAULT '',
Version4        CHAR(6) DEFAULT '',
Version5        CHAR(6) DEFAULT ''
);
CREATE

INSERT INTO tasks (task, job) VALUES (1, 1);
INSERT 4410388 1
select * from tasks;
task|job|version1|version2|version3|version4|version5
----+---+--------+--------+--------+--------+--------
   1|  1|        |        |        |        |
(1 row)

update tasks set version1='1',version2='2', version3='3', version4='4',
version5='5' where task=1;
UPDATE 1
select * from tasks;
FATAL:  unrecognized data from the backend.  It probably dumped core.
FATAL:  unrecognized data from the backend.  It probably dumped core.

EOF
test=>







--ELM904013936-3186-0_

--ELM904013936-3186-0_--

Re: [GENERAL] More details on Database corruption

From
Dimitri
Date:
It seems to be the same for me...
But I can see "tasks" table after restarting of psql,
so it doesn't crash the data files.

What can be usefull is  the messages in the server.log file:
Too Large Allocation Request ... File: mcxt.c Line: 232

I don't know the code of PG, but we can ask  PG "gurus" ...
Dimitri

On Thu, 13 Aug 1998, you wrote:
>Hi,
>
>I managed to recreate a simple example that's crashing postgres.  I am
>running on a DEC Alpha with Digital Unix Version 4.0d and Postgres
>3.2.   I tried this example several times, on several databases and it
>crashes every time.  We also re-built Postgres and still did not work.
>Here's the example. Can anybody please help?
>
>Thank you...
>George K.
>/***** INPUT FILE: hist.sql *******/
>
>drop table tasks;
>CREATE TABLE tasks (
>task  INT4 NOT NULL,
>job  INT4 NOT NULL,
>Version1 CHAR(6) DEFAULT '',
>Version2 CHAR(6) DEFAULT '',
>Version3 CHAR(6) DEFAULT '',
>Version4 CHAR(6) DEFAULT '',
>Version5 CHAR(6) DEFAULT ''
>);
>
>INSERT INTO tasks (task, job) VALUES (1, 1);
>select * from tasks;
>update tasks set version1='1',version2='2', version3='3', version4='4',
>version5='5' where task=1;
>select * from tasks;
>
>
>/****** OUTPUT FROM pgsql **********/
>test=> \i hist.sql
>drop table tasks;
>DROP
>CREATE TABLE tasks (
>task            INT4 NOT NULL,
>job             INT4 NOT NULL,
>Version1        CHAR(6) DEFAULT '',
>Version2        CHAR(6) DEFAULT '',
>Version3        CHAR(6) DEFAULT '',
>Version4        CHAR(6) DEFAULT '',
>Version5        CHAR(6) DEFAULT ''
>);
>CREATE
>
>INSERT INTO tasks (task, job) VALUES (1, 1);
>INSERT 4410388 1
>select * from tasks;
>task|job|version1|version2|version3|version4|version5
>----+---+--------+--------+--------+--------+--------
>   1|  1|        |        |        |        |
>(1 row)
>
>update tasks set version1='1',version2='2', version3='3', version4='4',
>version5='5' where task=1;
>UPDATE 1
>select * from tasks;
>FATAL:  unrecognized data from the backend.  It probably dumped core.
>FATAL:  unrecognized data from the backend.  It probably dumped core.
>
>EOF
>test=>
--
=====================================================
 Dimitri KRAVTCHUK  (dim)           Sun Microsystems
 Benchmark Engineer                 France
 dimitri@France.Sun.COM
=====================================================

Re: [GENERAL] More details on Database corruption

From
Guido Piazzi
Date:
On Thu, 13 Aug 1998, George Kousi wrote:

> CREATE TABLE tasks (
> task  INT4 NOT NULL,
> job  INT4 NOT NULL,
> Version1 CHAR(6) DEFAULT '',
> Version2 CHAR(6) DEFAULT '',
> Version3 CHAR(6) DEFAULT '',
> Version4 CHAR(6) DEFAULT '',
> Version5 CHAR(6) DEFAULT ''
> );

A zero-length string ('') is not a valid default value for a CHAR(6).
I replaced it with '      ' (six blanks) and all runs fine.

I run 6.3.1 on Linux 2.0.27 and your script fails on the first insert
without corruption problems.  I don't know why it only fails on update on
your system.

Regards - guido

------------------------------------------------------------------------
// Guido Carlo Piazzi                       Accompagnatore naturalistico
// gpiazzi@nemo.it            Visitate il sito WWW.ParcoDelTicino.Pmn.It
------------------------------------------------------------------------