The following bug has been logged online: Bug reference: 6293 Logged by: Teun Hoogendoorn Email address: t...@atsc.nl PostgreSQL version: 9.1 Operating system: Linux Description: JDBC driver performance Details:
Using the postgresql-9.1-901.jdbc3.jar driver instead of postgresql-9.0-801.jdbc3.jar drops performance dramatically. I think it has something to do with using ResultSetMetaData in Java. The postgres log shows me hundreds of identical query's when retrieving the ResultSetMetaData for a single query. I'm not using an ORM framework, just simple JDBC calls. Example: LOG: execute <unnamed>: SELECT c.oid, a.attnum, a.attname, c.relname, n.nspname, a.attnotnull OR (t.typtype = 'd' AND t.typnotnull), pg_catalog.pg_get_expr(d.adbin, d.adrelid) LIKE '%nextval(%' FROM pg_catalog.pg_class c JOIN pg_catalog.pg_namespace n ON (c.relnamespace = n.oid) JOIN pg_catalog.pg_attribute a ON (c.oid = a.attrelid) JOIN pg_catalog.pg_type t ON (a.atttypid = t.oid) LEFT JOIN pg_catalog.pg_attrdef d ON (d.adrelid = a.attrelid AND d.adnum = a.attnum) JOIN (SELECT 53886 AS oid , 1 AS attnum UNION ALL SELECT 53886, 2 UNION ALL SELECT 53886, 3 UNION ALL SELECT 53886, 4 UNION ALL SELECT 53886, 5 UNION ALL SELECT 53886, 6 UNION ALL SELECT 53886, 7 UNION ALL SELECT 53886, 8 UNION ALL SELECT 53886, 9 UNION ALL SELECT 53886, 10 UNION ALL SELECT 53886, 11 UNION ALL SELECT 53886, 12 UNION ALL SELECT 53886, 13 UNION ALL SELECT 53886, 14 UNION ALL SELECT 53886, 15 UNION ALL SELECT 53886, 16 UNION ALL SELECT 53886, 17 UNION ALL SELECT 53886, 18 UNION ALL SELECT 53886, 19 UNION ALL SELECT 53886, 20 UNION ALL SELECT 53886, 21 UNION ALL SELECT 53886, 22 UNION ALL SELECT 53886, 23 UNION ALL SELECT 53886, 24 UNION ALL SELECT 53886, 25 UNION ALL SELECT 53886, 26 UNION ALL SELECT 53886, 27 UNION ALL SELECT 53886, 28 UNION ALL SELECT 53886, 29 UNION ALL SELECT 53886, 30 UNION ALL SELECT 53886, 31 UNION ALL SELECT 53886, 32 UNION ALL SELECT 53886, 33 UNION ALL SELECT 53886, 34 UNION ALL SELECT 53886, 35 UNION ALL SELECT 53886, 36 UNION ALL SELECT 53886, 37 UNION ALL SELECT 53886, 38 UNION ALL SELECT 53886, 39 UNION ALL SELECT 53886, 40 UNION ALL SELECT 53886, 41 UNION ALL SELECT 53916, 1 UNION ALL SELECT 53916, 2 UNION ALL SELECT 53916, 3 UNION ALL SELECT 53916, 4 UNION ALL SELECT 53916, 5 UNION ALL SELECT 53916, 6 UNION ALL SELECT 53916, 7 UNION ALL SELECT 53916, 8 UNION ALL SELECT 53916, 9 UNION ALL SELECT 53916, 10 UNION ALL SELECT 53916, 11 UNION ALL SELECT 53916, 12 UNION ALL SELECT 53916, 13 UNION ALL SELECT 53916, 14 UNION ALL SELECT 53916, 15 UNION ALL SELECT 53916, 16 UNION ALL SELECT 53916, 17 UNION ALL SELECT 53916, 18 UNION ALL SELECT 53916, 19 UNION ALL SELECT 53916, 20) vals ON (c.oid = vals.oid AND a.attnum = vals.attnum) -- Sent via pgsql-bugs mailing list (pgsql-bugs@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-bugs
