[pgpool-hackers: 3345] Re: Reducing query issued by relcache

[Tatsuo Ishii]

> Currently relcache module issues 7+ queries to obtain various info
> from PostgreSQL system catalogs. Some of them are necessary for
> Pgpool-II to work with multiple version of PostgreSQL.
> 
> Idea is, if we already know the version of PostgreSQL, we can
> eliminate some of queries. For example, we need to know if
> pg_namespace exists and for this purpose we send a query against
> pg_class. But if we know that pg_namespace was introduced in
> PostgreSQL 7.3, we do not need to inquire pg_class.
> 
> So I have created a patch to implement the idea.
> 
> In my testing with "select * from t1" issues 7 queries. After the
> patch, it reduces to 3.

The patch has just been committed.
https://git.postgresql.org/gitweb/?p=pgpool2.git;a=commit;h=6282805d4ae3f7a76ed607c0124420b8fe4c8320

Best regards,
--
Tatsuo Ishii
SRA OSS, Inc. Japan
English: http://www.sraoss.co.jp/index_en.php
Japanese:http://www.sraoss.co.jp