… before going to production. Q: How would you migrate to XtradbCluster from a traditional Master Slave scenario when the data set is very large? Can… end, is how to start up a cluster from scratch (i.e. a standalone XtraDB Cluster machine, convert it to a cluster type… if you delete grastate.dat). So, it is appropriate for demo purposes when you would like to show that the full data is…
Post: Percona XtraDB Cluster - installation and setup webinar follow up Q&A
October 28, 2012 By 4 Comments
Post: Using any general purpose computer as a special purpose SIMD computer
May 16, 2011 By 5 Comments
…perspective, one must run a function on a large amount of input. Often times, the same …data infile ‘/tmp/words’ into table words (chars); Query OK, 6033 rows affected (0.01 sec) Records: 6033 Deleted…Shard-Query has no idea how to add parallelism in this case. It is data set agnostic, operating only…
Post: Innodb undo segment size and transaction isolation
January 12, 2011 By 3 Comments
… if transactions performed large amount of changes. There is something else you need to know – not … so row can be deleted on rollback, update and delete however need to put the old row …on to the main topic – how does transaction isolation affects purging ? Innodb is smart and trying to purge data …
Comment: Database problems in MySQL/PHP Applications
August 11, 2006 By 13 Comments
… with loosing data etc. Read more in my > Why MySQL Could be slow with Large Tables article. Deciding whether or not to let the database maintain referential integrity is just one of the factors that developers should consider when deciding when / how to create indexes. Foreign key references may add processing time to inserts, updates, and deletes but there are other…
Post: Identifying the load with the help of pt-query-digest and Percona Server
December 29, 2011 By 3 Comments
…to set it back to a value greater than 0, because otherwise you can have a really large…0.0002 1.00 0.00 DELETE poller_output # 20 0x428A588445FE580B 0…. “Query_time distribution” section shows how this query times mostly, which… queries that you can use to gather more data about the underlying tables…
Post: Filtered MySQL Replication
November 7, 2007 By 8 Comments
…to break such replication is also using multi-table update or delete statements, if you happen to…and it would be waste to pull binary logs to large variety of slaves? …data though it does not help if you would like to add more tables to be replicated to… It is in my todo to see how well MySQL 5.1 row …
Post: Hijacking Innodb Foreign Keys
January 2, 2012 By 2 Comments
…data change needs a table rebuild. In some real life production cases you might find tables which are large…checks=0; delete from parent; After these actions we have child table which points to non existing …you hostage. Do you have any better idea how to Hijack innodb Foreign Keys or drop them …
Post: MongoDB Approach to database synchronization
April 30, 2010 By 5 Comments
…to it which cause it to be inconsistent with data on the new Master. In MySQL world we can chose to…large databases. MongoDB approach used in Replication Sets is for failed master to scan its log files to… the new master (or delete them if they no …as previously looking at how replication done in Redis…
Post: Using VIEW to reduce number of tables used
September 28, 2007 By 12 Comments
…can’t be made large enough and so a lot of table reopens needs to happen which … VIEWs are significantly less expensive and cheap to “open”. How this could work ? Say you have “post…to ensure we do not insert data in the view which will be invisible. The VIEW approach works for SELECT, UPDATE, DELETE…
Post: MySQL Query Cache
July 27, 2006 By 70 Comments
…to be cached. Query must be deterministic – Query might provide same result no matter how many times it is run, if data… be seen as large value of Qcache_free_blocks relatively to Qcache_free_memory…delete+Com_update+Com_replace)/Qcache_hits . These are some numbers you can play with but it is hard to…
