… UNSIGNED NOT NULL, update_time DATETIME NOT NULL, …. INDEX `uid` (uid, update_time), INDEX `bar` (some_other_columns) …. ) ENGINE… (root@localhost) [test]> select update_date FROM foo order by update_date LIMIT 5; +———————+ | update_date | +———————+ | 0024-06-21 …
Comment: COUNT(*) vs COUNT(col)
April 25, 2007 By 45 Comments
… default ”, `comment_date` datetime NOT NULL default ’0000-00-00 00:00:00′, `comment_date_gmt` datetime NOT NULL default …count, even if it is not a unique index. For instance: mysql> explain select count(*) from wp_comments; …
Comment: How to find wrong indexing with glance view
March 8, 2010 By 27 Comments
… not null, order_amount decimal(10, 4) not null, order_date datetime not null, last_updated timestamp not null default current_timestamp… create the following indexes: unique index on order_id index on item_type_id index on locale_id index on currency_id index on operator_id…. Additionally I need an index on order_date to help with finding orders for a given date. 8 columns 6 indexes on single columns…
Post: Ultimate MySQL variable and status reference list
January 8, 2011 By 4 Comments
…_tmp_filesblogpercona.commanual Created_tmp_tablesblogpercona.commanual datadirblogpercona.commanual date_formatblogpercona.commanual datetime_formatblogpercona.commanual debugblogpercona.commanual debug_syncblogpercona.commanual debug_sync…
Comment: MySQL Indexing: Best Practices Webinar
August 8, 2012 By 3 Comments
… auto-increment primary key and an indexed datetime column, and use two queries: The first translates a date range to a primary key… tbl ” “WHERE dt_field BETWEEN %s AND %s”, (min_date, max_date)) The second uses two BETWEEN clauses to benefit from the… BETWEEN %s AND %s ” “GROUP BY user_id”, (min_date, max_date, mnm, mxm)): print (‘{0:3d}: {1:9.2f}’.format(*row…
