Обсуждение: MemoryContextAlloc: invalid request size 1969649011

hi everybody,

this query...:

my $tsql = qq{ insert into  user_month (select '$currentmonth'::date as
month,'*nopleid*',count(distinct uuid) from user_log where day<=now()::date
and day>(now()-interval '30 days')::date) };
my $tsth = $tdbh->prepare( $tsql );
$tsth->execute();

sometimes drops this error:
DBD::Pg::st execute failed: ERROR:  MemoryContextAlloc: invalid request size
1969649011

the table user_log has about 2.000.000 entries and the following structure:

 Column |          Type          | Modifiers
--------+------------------------+-----------
 day    | date                   |
 uuid   | character varying(31)  |
 pleid  | character varying(200) |
Indexes: user_log_day_idx,
         user_log_pleid_idx,
         user_log_uuid_idx

The system is postgresql-7.2-1PGDG on a redhat 7.2 system.
Looks like the postgresql asks the system for some 2gb ram... thats quiet a
lot (and i have read somewhere this is a magic border on intel systems).
The query gets executed while entrys are inserted into user_log by other
clients.
Do i have to lock the table before against inserts?

ideas?

thanks

Thilo Hille
thilo@resourcery.de

"Thilo Hille" <thilo@resourcery.de> writes:
> this query...:

> my $tsql = qq{ insert into  user_month (select '$currentmonth'::date as
> month,'*nopleid*',count(distinct uuid) from user_log where day<=now()::date
> and day>(now()-interval '30 days')::date) };
> my $tsth = $tdbh->prepare( $tsql );
> $tsth->execute();

> sometimes drops this error:
> DBD::Pg::st execute failed: ERROR:  MemoryContextAlloc: invalid request size
> 1969649011

This looks to me like a corrupted-data issue --- specifically, the
length word of some data value in the table has gotten clobbered and
now appears ridiculously large.

You should try to determine exactly which row(s) contain bad data.

            regards, tom lane

hi tom,
> > sometimes drops this error:
> > DBD::Pg::st execute failed: ERROR:  MemoryContextAlloc: invalid request
size
> > 1969649011
>
> This looks to me like a corrupted-data issue --- specifically, the
> length word of some data value in the table has gotten clobbered and
> now appears ridiculously large.
>
> You should try to determine exactly which row(s) contain bad data.
the error only occurs sometimes. if some rows had been corrupted shouldnt it
be reproduceable?
anyway, i try a dump/restore. it should fail when the table has corrupted
rows...

regards

Thilo Hille
thilo@resourcery.de

----- Original Message -----
From: Tom Lane <tgl@sss.pgh.pa.us>
To: Thilo Hille <thilo@resourcery.de>
Cc: <pgsql-novice@postgresql.org>
Sent: Thursday, August 08, 2002 4:25 AM
Subject: Re: [NOVICE] MemoryContextAlloc: invalid request size 1969649011


> "Thilo Hille" <thilo@resourcery.de> writes:
> > this query...:
>
> > my $tsql = qq{ insert into  user_month (select '$currentmonth'::date as
> > month,'*nopleid*',count(distinct uuid) from user_log where
day<=now()::date
> > and day>(now()-interval '30 days')::date) };
> > my $tsth = $tdbh->prepare( $tsql );
> > $tsth->execute();
>
> > sometimes drops this error:
> > DBD::Pg::st execute failed: ERROR:  MemoryContextAlloc: invalid request
size
> > 1969649011
>
> This looks to me like a corrupted-data issue --- specifically, the
> length word of some data value in the table has gotten clobbered and
> now appears ridiculously large.
>
> You should try to determine exactly which row(s) contain bad data.
>
> regards, tom lane
>
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