… my_message(ER_TOO_MANY_FIELDS, ER(ER_TOO_MANY_FIELDS), MYF(0)); DBUG_RETURN(1); } Which is, of …long comment on each field you reduce the number of different ENUM elements you can have, you are correct. There is…in a MySQL table. So what’s the maximum number of columns in a MySQL table? Well.. I…
Post: How Percona does a MySQL Performance Audit
November 24, 2008 By 17 Comments
…obvious things. This call is sometimes up to an hour long, if we’…status is. I can see the drive status, too. Sometimes a failed drive is …My goal here is to look at the my.cnf without seeing all the comments, which… checking for default users in the mysql.* tables, running mk-duplicate-key-checker to …
Post: Helgrinding MySQL with InnoDB for Synchronisation Errors, Fun and Profit
November 24, 2011 By 2 Comments
…comment: /* A problem: we assume that mutex_reset_lock word is a memory barrier, that is…mysql_select(THD*, Item***, TABLE_LIST*, unsigned int, List
Post: Caching techinques
August 8, 2006 By 11 Comments
…can be very helpful is caching data long term – ie if …is updated. This is how MySQL Query Cache works by removing all queries derived from the table if that table is…invalidated – approach used by MySQL Query Cache is too coarse invalidating a lot…to blog entries so if comment is added to post B you…
Post: Multi Range Read (MRR) in MySQL 5.6 and MariaDB 5.5
March 21, 2012 By 10 Comments
…secondary key tuple, a point primary key lookup is made against base table, the number of these point primary …taking far too long to execute, ~11 hours in case of MySQL 5.5 and ~5 hours in case of MySQL … c_comment order by revenue desc LIMIT 20; In-memory workload Now let’s see how effective is MRR …
Post: MySQL Query Cache
July 27, 2006 By 70 Comments
…MySQL Query Cache is – I’ve seen number of people being confused, thinking MySQL Query Cache is… data from table. Avoid comment (and space) … for rather long time for large…is efficient to cache whole objects rather than individual queries. No control on invalidation Table granularity is often too…
Post: ALTER TABLE: Creating Index by Sort and Buffer Pool Size
June 27, 2012 By 4 Comments
… column to have bunch of long random strings update sbtest …table which would look as following in terms of data and index size: mysql> show table…Comment: 1 row in set (0.00 sec) So we have about 3.7GB total size out of which 1.4GB is…is large enough to fit complete table with index (but is a bit too…
Post: Figuring out what limits MySQL Replication
March 7, 2007 By Leave a Comment
…long_query_time when it is set online, meaning changing it via set global long…MySQL Logs. Too bad MySQL Binary log is…is basically queries one query per line. mysqlbinlog almost provides what we’re looking for, if you strip out comments…
Post: How Percona Develops Open-Source Software
January 9, 2009 By 4 Comments
…commented that our development process doesn’t seem very open-source. That is… and puts it on the table. These builds are stamped with …is both generous and fair, and MySQL is free to take them without even asking permission, as long…. The second thing is that it takes far too long for patches to …
Post: Read/Write Splitting with PHP Webinar Questions Followup
January 23, 2013 By 4 Comments
… For example tables used for logging…MySQL Proxy 0.8.2 still says: “MySQL Proxy is…is probably a good reason to redesign my prototype to use hints embedded in SQL comments…long as the page remains in the buffer pool. But the read/write split solution is intended for cases where the query load is too…
