[pgpool-hackers: 3344] Reducing query issued by relcache

Tatsuo Ishii ishii at sraoss.co.jp
Tue Jun 25 14:56:31 JST 2019

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.

Best regards,
Tatsuo Ishii
SRA OSS, Inc. Japan
English: http://www.sraoss.co.jp/index_en.php
-------------- next part --------------
A non-text attachment was scrubbed...
Name: relcache.diff
Type: text/x-patch
Size: 11259 bytes
Desc: not available
URL: <http://www.sraoss.jp/pipermail/pgpool-hackers/attachments/20190625/6fc4c18d/attachment.bin>

More information about the pgpool-hackers mailing list