Bug #75705 [Opn->Dup]: pg_field_type() slow and consumes CPU on a large database

Edit report at https://bugs.php.net/bug.php?id=75705&edit=1 ID: 75705 Updated by: cmb@php.net Reported by: dmitry dot kunilov at gmail dot com Summary: pg_field_type() slow and consumes CPU on a large database -Status: Open +Status: Duplicate Type: Bug Package: PostgreSQL related PHP Version: 7.2.0 -Assigned To: +Assigned To: cmb Block user comment: N Private report: N New Comment: Closing as duplicate of https://github.com/php/php-src/issues/9692. Previous Comments: ------------------------------------------------------------------------ [2017-12-19 13:01:40] dmitry dot kunilov at gmail dot com Description: ------------ Our database has around 25K tables. Whenever a PHP script does a first call to pg_field_type(), it consumes a lot of CPU, memory and network traffic. This is reproducible with all PHP versions from 5 to 7.2 The problem was narrowed down to the following query performed from ext/pgsql/pgsql.c get_field_name(): select oid,typname from pg_type As postgresql defines several types for each table in the database, the above query produces over 76K rows on our system. All of those are put into a hashmap by get_field_name(). Obviously, rowset types present in pg_type table cannot be used as field types, and have to be excluded from the query. ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=75705&edit=1