… latency you must not have any long running updates. Queries or transactions containing multiple update queries which add up to long time. I… can be running update/delete with LIMIT in the loop, controlling maximum amount of values per batch in multiple row insert statement or Fetching data you’re planning to update/delete and having multiple queries to delete…
Post: The Doom of Multiple Storage Engines
May 8, 2010 By 22 Comments
… file when all transaction engines have their own ! Quality Assurance Multiple storage engines are much more complicated to test. And I… using multiple storage engines in the query you need to test all kinds of combination such as running multi-table update joining… enough. In fact people already do not love to mix multiple storage engines very actively because of potential complications involved. Now…
Post: INSERT ON DUPLICATE KEY UPDATE and REPLACE INTO
January 18, 2007 By 15 Comments
… Haddad writes about REPLACE INTO and INSERT ON DUPLICATE KEY UPDATE. Really, Why MySQL has both of these, especially both are… you could set it to replace multiple values at the same time just as you have multiple value INSERT. As a side… with REPLACE was – many people tried to use it like update accessing previous column value, for example doing something like REPLACE…
Post: Multiple purge threads in Percona Server 5.1.56 and MySQL 5.6.2
May 3, 2011 By 13 Comments
… 5.6.2 one can have multiple dedicated purge threads. Percona Server 5.1 supports multiple purge threads too, although using more… rest of the scripts and results) and here are the updated 5.6.2 results. The difference against baseline 5.6… working through the history list, at the cost of TPS. Multiple dedicated purge threads even with the change are not effective…
Post: Using Multiple Key Caches for MyISAM Scalability
November 26, 2008 By 8 Comments
… chosen a way of using Multiple Tables to solve Table Locks problem you can also use multiple Key Caches to reduce or… their relative use activity. I just summed rows modified and updated but you can surely use different formula if you like… set (0.00 sec) So going through complex or not multiple key cache creation exercise you probably wonder how much performance…
Post: Innodb Table Locks
July 31, 2012 By 4 Comments
… 53173, OS thread handle 0x7ff75963b700, query id 3929840 localhost root Updating update sbtest set c=concat(c,’c') TABLE LOCK table `sbtest… because update needs to lock the rows in exclusive mode. Similar to IS lock IX is rather lose – I can have multiple update… it comes to Table Level Locks. For MyISAM tables running UPDATE query on the table is essentially equivalent to locking table…
Post: Updated msl (microslow) patch, installation walk-through!
April 20, 2008 By 17 Comments
For a couple of months there have been no updates to our msl patch, however recently I managed some time …=name Log only the queries that followed certain execution plan. Multiple flags allowed in a comma-separated string. [qc_miss, full… how verbose the messages to your slow log will be. Multiple flags allowed in a comma-separated string. [microtime, query_plan…
Post: Updated Percona Server and Percona XtraBackup documentation
October 3, 2011 By Leave a Comment
… documentation source along with our source code and support for multiple output formats. This moves our documentation workflow to be the…. We have also set up a Jenkins job to automatically update the documentation on the percona.com web site when changes… the Drizzle project. The end result? Better and more frequently updated documentation.
Post: Sharing an auto_increment value across multiple MySQL tables
October 4, 2010 By 9 Comments
… 1 # each insert does two operations to get the value: UPDATE option2 SET id=@id:=id+1; SELECT @id; So which… threads are perpetually in a state of ‘Searching rows for update‘ – which is what I suspect is better described as waiting…
Post: Should we give a MySQL Query Cache a second chance ?
April 10, 2011 By 64 Comments
… for match. Protection from Multiple Misses So you have item invalidated from query cache and there are multiple connection requesting the same… on the client. Delayed Updates Delayed Updates is complement to delayed invalidation. In many applications you have updates which are kind of not…
