… you‘re talking about using a temporary table to store an interim result set, and then use that to ultimately produce the result you want… to add a column to the table, and populate the rows you want to choose (movies, in this case) with values known to be consecutive. Then you… Dynamic Pivot, the straight join, can you explain more about why you thought about doing that and why it helped? When I did not…
Post: The small improvements of MySQL 5.6: Duplicate Index Detection
May 31, 2013 By Leave a Comment
… not have time to analyze it in-depth. If you try to do something like this in MySQL 5.5, you will succeed without… columns, but also for filtering by just the first one. Why can’t MySQL enforce this kind of constraints? For many… Duplicate Indexes 1 # Total Indexes 2 By the way, if you want to get more familiar with this and other particularities of the…
Post: Choosing a MySQL HA Solution - Post-Webinar Q&A
June 7, 2013 By Leave a Comment
… for the optimal production deployment you want two identical physical boxes with at least 4 NIC ports. Why 4? Two of those NICs… status variables that you might want to keep an eye on to prevent a problem before it occurs. For example, if you see a large… have to admit that this was probably the most interesting question asked; my initial reaction was, honestly, why would you ever want to use MySQL…
Post: Experiences with the McAfee MySQL Audit Plugin
May 23, 2013 By 4 Comments
… be set to control what is logged by the plugin: – audit_record_cmds : This is the list of commands you want written to the… had to be a capital Q in Quit for that to work, and no, my code-fu was not enough to understand why that…_objs : List of database objects (tables, according to the docs) for which you want events written to the log. – audit_whitelist_users : This one…
Post: Replication in MySQL 5.6: GTIDs benefits and limitations - Part 1
May 21, 2013 By 8 Comments
… your servers from regular replication to GTID replication. But if you are running a production system, you will probably want to gradually enable GTID replication…: No Slave_SQL_Running: Yes [...] The error log tells us why the IO thread has not started: 2013-05-17 13… GTID_MODE ON, Error_code: 1593 So unfortunately if you want replication to work correctly, gtid_mode must be ON on all servers…
Comment: ZFS on Linux and MySQL
May 31, 2013 By 17 Comments
Nice to see this writeup on ZFS and MySQL. One question, why with 192GB of memory, did you limit the ARC to 4GB? Also wondering if any one is using ZFS and MySQL to thin… copies of the source database. Would be interested if someone wanted to contribute on the MySQL side. Interesting that on Wikipedia Data…
Post: Implementing SchemaSpy in your MySQL environment
June 4, 2013 By 2 Comments
… to see which tables are referenced the most, and which are candidates for dropping (why keep old data if you don’t need to?). I get up to speed a lot faster and can contribute to the Development… the most useful component of SchemaSpy, I don’t want to leave you with the impression that this is the only component of…
Post: Why MySQL Performance at Low Concurrency is Important
March 27, 2013 By 8 Comments
…. This time I want to target an opposite question: why MySQL performance at low concurrency is important for you. I decided to write about this… to compare apples to apples is 8. Running a comparable benchmark with concurrency of 1 and the same tool is not possible. Want to talk more about performance? Come to Percona Live MySQL Conference and Expo April 22…
Post: Benchmarking Percona Server TokuDB vs InnoDB
May 7, 2013 By 32 Comments
… results are not quite stable, that is why I also show 5-minute moving averages to TokuDB. So TokuDB shows about 2… will affect select performance, so we will need to measure that also. And, if you want to repeat this benchmark, the sysbench code is on Launchpad lp:~vadim-tk/sysbench/insert-roll-2, command line to run…
Post: trx descriptors: MySQL performance improvements in Percona Server 5.5.30-30.2
April 12, 2013 By 3 Comments
… is created for each SELECT, even within the same transaction. Why is that a major problem for MySQL scalability? The scan… you want to benefit from that optimization, you basically want all or most of your transactions to be read-only. Sometimes you may also want to modify your applications to…
