… you find them get rid of them. Note: Duplicate indexes apply to indexes of the same time. It may make sense to have indexes… in index is significant, index (A,B) is not duplicate to index (B,A) So now what are Redundant indexes when ? I call redundant indexes BTREE indexes which are prefix of other index, for example…
Post: How Percona does a MySQL Performance Audit
November 24, 2008 By 17 Comments
… in the mysql.* tables, running mk-duplicate-key-checker to find redundant indexes, and so on. As with settings and status, these set… big gains. Schema, query, and index optimization Analyzing and optimizing a server’s table and index structures, and the queries that run…. You cannot consider any one of these factors (schema, queries, indexing) in isolation, because they are tightly bound together, and tweaking…
Post: Extending Index for Innodb tables can hurt performance in a surprising way
May 22, 2010 By 9 Comments
… original index it will quite likely be unable to use new index to full extent. What is solution ? You can have “redundant” indexes on…) and (a,b) indexes and in the end decides to use neither rather doing full index scan until it finds a=100. This… be very careful applying index changes from mk-duplicate-key-checker key checker when it comes to redundant indexes. If you have query…
Post: Finding out largest tables on MySQL Server
February 4, 2008 By 24 Comments
… query I use for the purpose so I can easily find it later, plus it is quite handy in a way… which tables may be worth to review in terms of indexes. Large index size compared to data size often indicates there is a lot of indexes (so it is well possible there are some duplicates, redundant or simply unused indexes among them) or may…
Comment: Duplicate indexes and redundant indexes
September 17, 2006 By 38 Comments
The tool to find duplicate/redundant indexes and foreign keys is on MySQL Forge (http://forge.mysql.com/) and at http://www.xaprb.com/blog/2006/08/28/how-to-find-duplicate-and-redundant-indexes-in-mysql/.
Post: How to recover deleted rows from an InnoDB Tablespace
February 20, 2012 By 3 Comments
… our tablespace located (-f) The row format can be -4 (REDUNDANT) or -5 (COMPACT). From 5.0.3 the default format…) INNODB_SYS_INDEXES Percona Server has some extra tables in INFORMATION_SCHEMA that can help us to find the different indexes and types. mysql (information_schema) > select i.INDEX_ID, i.NAME FROM INNODB_SYS_INDEXES as i…
Post: RAID and Scale Out Discussions
June 12, 2007 By 3 Comments
…than direct disks. For example for BoardReader now indexing almost billion of forum posts we decided …would use crappy boxes as redundant array of inexpensive servers, basically moving redundancy one way up from the …not provide high volume internal storage option. Ie find me 12 or more hot swap SATA …
Post: Trying Archive Storage Engine
November 12, 2006 By 6 Comments
…compression rate for this table which is heavily redundant (urls, referers, user agents etc) To check if…storage engine using for reads – I could not find it as difference could be due to …storing something which needs no updates and no indexes, however compression ratio is not perfect, configuration …
Post: Shard-Query EC2 images available
May 11, 2011 By 2 Comments
…/dev/null 2>&1 < /dev/null done; Where to find the images Amazon ID Name Arch Notesami-… that in the demonstration each node will contain redundant, but non-accessed data for all configurations … 241 Data_length: 1616904192 Max_data_length: 0 Index_length: 539279360 Data_free: 4194304 Auto_increment: …
