…where your MySQL Support contract can be handy. Conclusion Understanding where MySQL can allocate memory…
Post: MySQL Indexing Best Practices: Webinar Questions Followup
August 16, 2012 By 4 Comments
…index. Q: We have a database that has about 400GB of indexes. The indexes can’t fit in memory…where DB structure is prepdefined A: MySQL Server will not automatically define any indexes…in binary form and store as VARBINARY(16) for …mysql use index for group by? A: If you have Index on the column MySQL…
Post: Dynamic row format for MEMORY tables
September 6, 2011 By 5 Comments
…MEMORY tables for MySQL…stored in the fixed-length format, either wasting space (VARCHAR) or outright impossible (BLOB). Indexes on…depending on MEMORY …memory savings. One quite important feature is missing from this release however: MyISAM tables are still used for temporary tables where the MEMORY…
Post: Full Text Search Webinar Questions Followup
August 24, 2012 By 5 Comments
…. Since RT indexes are in volatile memory, not stored on disk, you are responsible for integrating new data with the on-disk Sphinx index periodically by… S. commented on the blog post where I announced the webinar: We evaluated MySQL vs Solr. I was able to index all the data…
Post: How Percona does a MySQL Performance Audit
November 24, 2008 By 17 Comments
…memory, and so on in the boot output. In addition, at the tail it has information on core dumps and so on…mysql.* tables, running mk-duplicate-key-checker to find redundant indexes, and so on… — it’s a question of where they fall on the scale. Now …that have a lot of stored procedures, which are more …
Post: The MySQL optimizer, the OS cache, and sequential versus random I/O
April 28, 2008 By 17 Comments
…how a given storage engine stores its data). I’ll… 117 Data_length: 17217646764 Index_length: 11993816064 mysql> show table status like ‘dim1′\G…indexed on every table, and there’s a separate index on every column in the WHERE… operations, assuming that the indexes are fully in memory. When you divide …
Post: Connecting orphaned .ibd files
May 13, 2011 By 19 Comments
… actor’s indexes: mysql> select * from INNODB_SYS_INDEXES WHERE TABLE_ID = 13G *************************** 1… indexes are stored in actor.ibd as well. But where is …NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP, PRIMARY KEY…exists in the tablespace InnoDB: memory cache! To refrain from…
Post: Heikki Tuuri Innodb answers - Part I
October 26, 2007 By 19 Comments
…hash indexes require that the prefix is stored in every record R. An adaptive hash index tries to guess where… where INNODB is using most of the system’s memory the kernel can decide (incorrectly) to swap out MySQL….in the same order, for a recovery based on MySQL‘s binlog to work. Of course, if you…
Post: Falcon Storage Engine Design Review
January 12, 2007 By 19 Comments
…cached, which are all on different pages you need 100K of memory not 8-16M … do quite frequently with MySQL 
[+] Compact Indexes Compact Indexes are great. Huge indexes is where large portion of …regarding handling fragmentation – what happens on row updates, are they stored in the same position …
Post: To pack or not to pack - MyISAM Key compression
May 13, 2006 By 4 Comments
…stored in the index even if it is not packed. Compressed blocks need to be treated differently. For uncompressed index blocks MySQL…where c like “%abc%” order by c limit 1 – forward index scan select c from t1 where…large memory areas. Reverse index scan performance got some 8 times faster and join on…
