… refreshed. This is similar to storing the results of a query in Memcache. When the cache “expires”,… created, or last refeshed. The incremental method is somewhat conceptually similar to using mysql binary logs… is actually another MV. This saves a significant amount of time. If this MV did not…
Post: Flexviews - part 3 - improving query performance using materialized views
April 4, 2011 By 12 Comments
Post: Shard-Query EC2 images available
May 11, 2011 By 2 Comments
…of the input data. The ICE schema was discussed in the comments of the last… character_set_client = @saved_cs_client */; CREATE TABLE `dim…’; mysql> use ontime1; Database changed mysql> show table…query command, called pivot_results cd shard-query/ $ ./run_query < queries.sql | tee raw |./pivot_results…
Post: The perils of uniform hardware and RAID auto-learn cycles
November 16, 2010 By 16 Comments
Last night a customer had an emergency in selected machines on a large cluster of quite uniform database servers. Some of…of hours). Queries were taking multiple seconds to execute instead of…of the failing machines. The result: the battery-backed cache was in write-through mode instead of… and saving …
Post: High-Performance Click Analysis with MySQL
December 22, 2008 By 13 Comments
… dozens of different types of slicing and dicing. And as a result, one of the … None of the big three (Google, Yahoo, MSN) provides real-time reporting last … can. You can save very large amounts of space. Choose primary…long queries that read a lot of rows — MySQL can’t handle too many of those…
Post: How Percona does a MySQL Performance Audit
November 24, 2008 By 17 Comments
…save this part of the analysis for last. You cannot consider any one of these factors (schema, queries…of which we can frequently help customers set up much more efficiently and with better results, due to our knowledge of…
Comment: Neat tricks for the MySQL command-line pager
June 24, 2008 By 10 Comments
… pager for two things: 1) Save the results of the last query 2) Replace EXPLAIN with mk-visual-explain Unfortunately, MySQL 5.0.51a and earlier… = ) { $out .= $line; } # Log results to a file (always useful) # But only ever save one 
open (PAGER_LOG, ‘>/tmp/mysql_pager.log’); print PAGER…
Post: How to recover deleted rows from an InnoDB Tablespace
February 20, 2012 By 3 Comments
… [...] The second method has the same result, 0-26 is our primary key…recover and save it in another file. This is the output of our example: … the last step is to import it in our database: mysql (employees) > LOAD…Query OK, 3 rows affected (0.01 sec) Records: 3 Deleted: 0 Skipped: 0 Warnings: 0 mysql…
Post: MySQL Crash Recovery
July 30, 2006 By 26 Comments
… wrong query results days…last committed transactions but it is it. It is Performance of…MySQL 5.0 XA is taking care of this synchronization. .frm Corruption – Few people know MySQL…queries. Full table scan queries allow to preload table data ether in storage engine caches or in OS cache. You can save…
Post: Implementing efficient counters with MySQL
July 1, 2007 By 16 Comments
…byte rows in average. 10mil of posts result in 20GB table which may …solutions you can use memcache + another mysql instance (or simply the database which… the chunk in single transaction saving on log commits significantly. I …views within last hour has to run rather complicated group by query ? Sure …
Post: Living with backups
November 6, 2008 By 28 Comments
…last sentence, but it is not important right now. Either way the data is out and ready to save… from MySQL data directory will result in a total disaster after MySQL stops responding to the incoming queries … problems to happen on the working instance of MySQL. Such danger may for example come from…
