…your 150 GB table! If you have inserted in an ascending order of the PRIMARY KEY, then InnoDB should have placed the rows in contiguous blocks of…
Post: Why Index could refuse to work ?
September 8, 2006 By 13 Comments
…the index. Lets check if your guess is right: mysql> explain select * from article where article_id=”10″; +—-+————-+———+——+—————+———+———+——-+——+————-+ | id | select_type | table…
Post: What to tune in MySQL Server after installation
September 29, 2006 By 116 Comments
…the data so you need to leave memory for it as well, and data can be much larger than indexes in many cases. Check…of your tables open. It uses some OS resources and some memory but for modern hardware it is typically not the…
Post: How Percona does a MySQL Performance Audit
November 24, 2008 By 17 Comments
…the query, the server could have died. The ORM should just be running the query, and if the query fails, then you know from the error code that the…of other things I’ll look at, including checking for default users in the mysql.* tables, running mk-duplicate-key-checker to find redundant indexes…
Post: Choosing innodb_buffer_pool_size
November 3, 2007 By 38 Comments
…you should keep into account is Innodb allocates more memory in structures related to buffer pool than you specify for it – I just checked…the innodb buffer pool. I guess these clarifications work better than 70-80% recommendation and of course you should…
Post: MySQL Crash Recovery
July 30, 2006 By 26 Comments
…the problem I use tiny script which moves out all MyISAM tables out of MySQL database directory, checks…your workload. I should also mention if you have innodb_file_per_table=1 your recovery speed will depend on number of Innodb tables you…
Post: Falcon Storage Engine Design Review
January 12, 2007 By 19 Comments
…indexes really are. [-] No “using index” Falcon always have to check the row data even if you retrieve only columns which are in the index…you traverse significant portion of the table (or data which is locally stored but in random order). In my opinion this however should…
Post: Using MyISAM in production
June 17, 2006 By 35 Comments
… discovered etc. You should not think … non-checked tables fail with table does …you enable this option – globally, for table or for set of statements (by using LOCK TABLES/UNLOCK TABLES) be careful…of crash your index and data will likely be very much out of sync and if you do not repair the table you…
Post: ORDER BY ... LIMIT Performance Optimization
September 1, 2006 By 93 Comments
…the index can be used to satisfy order by, index however will not be helpful to check c=5 (unless it is index covered query). Index…index usage for order by. Sort by column in leading table if you have JOIN with ORDER BY … LIMIT you should…
Post: Make your file system error resilient
August 24, 2011 By 8 Comments
…of other nasty problems especially for database server. Second. The question comes to what you care the most – Do you care about consistency or availability ? Are you…check functions for your data partition and just check it manually as needed, same as you would every so often check MySQL tables…
