[pgpool-general: 8871] Re: Prepared statements over pgpool ?

[Tatsuo Ishii]

> Hello !
> 
> I'm trying to use pgpool (4.4.3) to pool connections to postgresql, to
> enforce a lower max_connections.
> 
> I'm getting errors on prepared statements from osm2pgsql, |Query is in
> the form `|||EXECUTE mark_rels_by_way(404720865)|`
> |
> 
> |Errors logged by pgpool :
> |
> 
> FATAL: unable to bind
> 
> DETAIL: cannot get parse message "mark_rels_by_way"
> 
> 
> This looks a lot like an old unsolved issue from osm2pgsql
> https://github.com/openstreetmap/osm2pgsql/issues/878
> 
> 
> My current configuration include a single backend and
> 
> backend_clustering_mode = 'raw'
> 
> process_management_mode = dynamic
> 
> process_management_strategy = lazy
> 
> num_init_children = 150
> 
> min_spare_children = 5
> 
> max_spare_children = 20
> 
> connection_cache = on
> 
> 
> Are prepared statements possible over pgpool ? (looks like they should
> be since documentation mention PREPARE/EXECUTE/DEALLOCATE commands)

Yes, pgpool supports PREPARE/EXECUTE/DEALLOCATE.

> Is there a specific configuration that breaks them ? or a specific
> configuration to allow them ?

No, they can be used without any specific configuration.

Can you share pgpool log with:

log_client_messages = on

This will reveal what osm2pgsql is sending to pgpool and will be
useful for investing the issue. Please make sure that the log file
includes all logs since "mark_rels_by_way" first appears so that I can
track how the messages are handled by pgpool.

Best reagards,
--
Tatsuo Ishii
SRA OSS LLC
English: http://www.sraoss.co.jp/index_en/
Japanese:http://www.sraoss.co.jp