… 10 sec to see how stable the performance is, and it really helps to observe some artifacts, as you will see in following graphs…. In general I have very good experience with this card, and it seems suitable to work with MySQL. I will publish sysbench oltp benchmarks running MySQL on…
Comment: Emulating global transaction ID with pt-heartbeat
April 24, 2012 By 6 Comments
… from intermediate slaves to master and knowing that mysql does not have … logs is very tedious but how about ‘row based replication’ ? i … can tell C to start replicating from A with “relay_master_log_file: …This should work fine in ‘row based replication’ correct ? because even pointing to previous …
Comment: ext4 vs xfs on SSD
May 3, 2012 By 23 Comments
…to assert that XFS is the way to go for MySQL, but I’m not sure how frequently they benchmark XFS vs ext4, and how…MySQL DBs with ext4, and it’s been working great for the past 7 months. I recently had an interesting conversation with…
Post: Joining many tables in MySQL - optimizer_search_depth
April 20, 2012 By 5 Comments
…how automatic selection works – it picks value of min(number of tables, 7) essentially limiting search depth to…in join I think faster execution plan computation would be more important than backward compatibility. In MySQL 5.6 things are likely to…
Post: Percona Live MySQL Conference & Expo Was A Great Event
April 17, 2012 By 2 Comments
…lot of people arrived with some uncertainty about how it would …in only a few months, without momentum, and we had to work with the space and dates that were available. In…to host the speaker slides in a central repository so the knowledge shared in the conference will be available to all in the MySQL…
Post: Join Optimizations in MySQL 5.6 and MariaDB 5.5
April 4, 2012 By 2 Comments
… the third blog post in the series of blog posts leading up to the talk comparing the optimizer enhancements in MySQL 5.6 and… available in both MySQL 5.6 and MariaDB 5.5. You can read more about BKA in MySQL 5.6 here and BKA in MariaDB… Join. This join algorithm only works with equi-joins. Now let me briefly explain how hash join algorithm works. Suppose you have two tables…
Post: Troubleshooting MySQL Memory Usage
March 21, 2012 By 3 Comments
… to connections and identified application which causes excessive memory usage you might look at how it uses MySQL to identify potential causes. Is it working with large blobs ? Using user variables ? Prepared Statements ? memory tables ? In a lot…
Post: How FLUSH TABLES WITH READ LOCK works with Innodb Tables
March 23, 2012 By 20 Comments
…WITH READ LOCK to temporary make MySQL read only. In many cases the period for which server has to…to complete this statement. Lets look at what the problem is. As of MySQL 5.5 FLUSH TABLES WITH READ LOCK does not work…to complete. Here is example how it can look: mysql> show processlist; …
Post: Multi Range Read (MRR) in MySQL 5.6 and MariaDB 5.5
March 21, 2012 By 10 Comments
… introduces a different variable to control the MRR buffer size mrr_buffer_size. Both buffer sizes default to 256K in MySQL 5.6 and… bug in MySQL 5.6 code? As MRR was used in both MySQL 5.6 and MariaDB 5.5. Handler_mrr_rowid_refills counts how… works only with joins and specifically with Block Access Join Algorithms. So I am not going to cover it here, but will cover it in…
Post: Index Condition Pushdown in MySQL 5.6 and MariaDB 5.5 and its performance impact
March 12, 2012 By 12 Comments
I have been working with Peter in preparation for the talk comparing the optimizer enhancements in MySQL 5.6 and MariaDB 5.5. We are taking a look at and benchmarking optimizer enhancements one by one. So in… new optimizer enhancement Index Condition Pushdown (ICP). Its available in both MySQL 5.6 and MariaDB 5.5 Now let’s take…
