Comments on: Using INFORMATION_SCHEMA instead of shell scripting

By: nik

nik — Wed, 22 Jul 2009 19:03:48 +0000

Todd, the great script. Very useful.

By: Mike Myles

Mike Myles — Tue, 09 Dec 2008 17:44:31 +0000

This is a great post. It opened my eyes to a whole new way of controlling my DB. Funny how sometimes you just need a little ‘inspiration’ and your mind will open up to a plethora of new possibilities. THANK YOU FOR THIS POST!

By: peter

peter — Tue, 25 Nov 2008 16:09:55 +0000

Nmike,

Information Schema is not really the table – MySQL scans the databases finding all the tables and putting their stats in the temporaty table which is later used for queries. This is why it takes so long time.

By: Kay Roepke

Kay Roepke — Tue, 25 Nov 2008 11:35:50 +0000

Metadata, baby, metadata Powerful stuff…

By: nmike

nmike — Tue, 25 Nov 2008 10:46:17 +0000

ниодного индекса в таблице TABLES – ну ппц просто.
запросы на ней просто ужос.

а так, мускул в этом отношении не только с этими таблицами использовать можно – для разный мелких задач такой путь тоже подходит. ну или сформировать csv например из какойто таблицы, причем можно сразу сделать некоторую обработку.

By: peter

peter — Tue, 25 Nov 2008 05:33:32 +0000

Todd,

Yes good note. You can pipe it too which is better in many cases. I just used 2 different boxes in this case so outfile was easier.

By: Todd

Todd — Tue, 25 Nov 2008 05:19:13 +0000

Another fun trick is to use INFORMATION_SCHEMA tables to generate SQL statements, and pipe them back into MySQL:

mysql -uroot -e”SELECT concat(’ALTER TABLE ‘,table_schema,’.',table_name, ‘ ENGINE = MyISAM;’) `#sql` FROM information_schema.tables WHERE engine=’innodb’ AND table_schema = ‘test’;” | mysql -uroot