…to modify a table (any non-temporary table) can… locks to shared (S) locks, these S locks prevent X locks …is no need to scan buffer pool for AHI entries after the B-trees for the tablespace have been dropped…is sufficient to skip just one (e.g. the first one). Bug fixed #1081003 (Alexey Kopytov). Slow…
Post: Heikki Tuuri Innodb answers - Part I
October 26, 2007 By 19 Comments
…is: for small tables, everything can reside within a single extent. For big tables…is attempted. btr0cur.h: /* In the pessimistic delete, if the page data size drops below this limit, merging it to a neighbor is… not lock the ‘gaps’, and it does not lock …seek on disk which slows down throughput. If …
Post: Working with large data sets in MySQL
July 5, 2007 By 12 Comments
… will lock tables for very long time and Innodb can get too many old row versions to deal with which can slow down… hours (this is indeed one of the big reasons to use Innodb even if you do not care about Table Locks or transactions… performance may drop performance order of magnitude. This is actually one of the reasons I try to keep data in smaller tables whenever…
Post: Performance impact of complex queries
January 17, 2007 By 11 Comments
… effect but the truth is it still happens. Disk Starvation As Cache efficiency drops more requests have to …2.4 times I could make single full table scan query to slow things that bad, so “ls” would … is great idea if you have one. Even if you use Innodb tables and so do not suffer from table locks…
Post: Heikki Tuuri answers to Innodb questions, Part II
November 4, 2007 By 13 Comments
…data smaller) or can a bit slow it down. Plus there were … for these non-mysql processes drops rapidly when you increase the … fairly large Innodb table (150GB) that is showing poor performance for full table scans. … online reorganize which locks and reorganizes small portions of table online. Q38: …
Post: Adaptive flushing in MySQL 5.6
September 4, 2012 By 8 Comments
…/innodb-flushing-a-lot-of-memory-and-slow-disk/ http://www.mysqlperformanceblog.com/2011/01/…is prolonged periods of time (up to few minutes) when throughput drops to 0, and the system is kind of locked…, so there is a room for improvement. Relevant MySQL options: innodb_file_per_table = true innodb_…
Post: Detailed review of Tokutek storage engine
April 28, 2009 By 21 Comments
…is a disk-based, read-write transactional storage engine that is based on special “fractal tree indexesâ€. Fractal Trees are a drop…is mysqldump/mysqlhotcopy. It is not fully transparent backup, as it applied TABLE LOCK on copying table… of RAM memory and slow inserts. This is where I think Tokutek…
