Re: (long) What's the problem?

David Olbersen wrote:
> Anybody have any ideas about a problem with this query?
>
> urldb2=> EXPLAIN
> urldb2-> SELECT
> urldb2-> id,
> urldb2-> source,
> urldb2-> insertedby,
> urldb2-> insertedon,
> urldb2-> priority
> urldb2-> FROM
> urldb2-> indexscan
> urldb2-> WHERE
> urldb2-> lower(
> urldb2-> substring(
> urldb2-> urlhost( source ), rposition( 'www.', urlhost( source ) ) + 2
> urldb2-> )
> urldb2-> ) ~ '^q.*'
> urldb2-> ORDER BY source;
>
> QUERY PLAN
> -------------------------------------------------------------------------------------------------------------------------------------------
> Sort (cost=23.50..23.50 rows=3 width=48)
> Sort Key: source
> -> Seq Scan on indexscan (cost=0.00..23.47 rows=3 width=48)
> Filter: (lower("substring"(urlhost(source), (rposition('www.'::text, (urlhost(source))::character varying) + 2))) ~ '^q.*'::text)
> (4 rows)
>
> OK, cost=23.50..23.50, should be a quickie. I'll EXPLAIN ANALYZE just to be safe:
>
> urldb2=> EXPLAIN ANALYZE
> urldb2-> SELECT
> urldb2-> id,
> urldb2-> source,
> urldb2-> insertedby,
> urldb2-> insertedon,
> urldb2-> priority
> urldb2-> FROM
> urldb2-> indexscan
> urldb2-> WHERE
> urldb2-> lower(
> urldb2-> substring(
> urldb2-> urlhost( source ), rposition( 'www.', urlhost( source ) ) + 2
> urldb2-> )
> urldb2-> ) ~ '^q.*'
> urldb2-> ORDER BY source;
>
> 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.

If I would be you I would unlimit the coresize in the environment the
postmaster is running, eventually recompile with debug symbols enabled
and look at the stack backtrace of the coredump created when then
backend crashes.

Jan

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