21.2. Database

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DB issues vary by the database being used. Study the documentation for your database or check with your database administrator.

MySQL

If you use the MySQL table type MyISAM (which is the default), and have deleted a large part of a table or if you have made many changes to a table with variable-length rows (tables that have VARCHAR, BLOB or TEXT columns), you need to defragment the datafile (tables) with the "optimize" command.

You should try this if the mysqld daemon needs a lot of your CPU time. Optimize the tables - ticket, ticket_history and article (see Script 21.2 below).

shell$ mysql -u user -p database
mysql$ optimize table ticket;
mysql$ optimize table ticket_history;
mysql$ optimize table article;

PostgreSQL

PostgreSQL is best tuned by modifying the postgresql.conf file in your PostgreSQL data directory. For advice on how to do this, see these articles:

http://www.revsys.com/writings/postgresql-performance.html

http://varlena.com/GeneralBits/Tidbits/perf.html

http://varlena.com/GeneralBits/Tidbits/annotated_conf_e.html

If performance is still not satisfactory, we suggest that you join the PostgreSQL Performance mailing list ( http://www.postgresql.org/community/lists/ ), and ask questions there. The folks on the PostgreSQL list are very friendly and can probably help.