… and timing much differently than traditional hardware, …production deployment you want two identical physical boxes with… storage engine) in between the actual master …mysql/servers.frm’ ERROR: 1033 Incorrect information in file: ‘./mysql/servers.frm’ Running mysql…and insert a few rows into an InnoDB …
Post: Is your MySQL buffer pool warm? Make it sweat!
April 16, 2013 By 6 Comments
…See part two for handling massive slow log volume.) The slow logs are served, via HTTP, by mysql_slowlogd… step because update statements that match no rows or insert statements that have duplicate key …warmup. The y axis is logarithmic, so the difference between the IO usage is 2 orders of magnitude…
Post: More on MySQL transaction descriptors optimization
April 26, 2013 By Leave a Comment
… somewhere in between of MySQL 5.5 and MySQL 5.6. In order to understand more about differences between results we… reportedly Dimitri was using 8 tables with 1M rows each (about 2.1GB) for his tests, while… on a single-node (on the left) vs. two-node (on the right) configuration. No surprises here,…
Post: Is Synchronous Replication right for your app?
May 14, 2013 By 18 Comments
…worst packet round trip time (RTT) between any two nodes in your cluster. Transaction apply … MySQL replication from this instance, since MySQL replication is asynchronous. What about semi-sync MySQL replication…does NOT mean you can’t modify different rows simultaneously. You can. It does NOT …
Post: Understanding the maximum number of columns in a MySQL table
April 8, 2013 By 5 Comments
…to avoid bugs with small static rows in MySQL */ reclength=max(file->min_record_length… intervals, not actual intervals, so two ENUM columns both having the options ‘Y… you reduce the number of different ENUM elements you can have, you… for a table in MySQL is somewhere between 191 and 2829, depending …
Comment: MySQL Partitioning - can save you or kill you
April 30, 2013 By 45 Comments
…MySQL. PARTITIONs are scanned one at a time. (Please provide specific references if you find otherwise.) I would argue that single-row queries (SELECT, INSERT, DELETE, UPDATE) are similar in speed between… makes very little difference. * If it …would mostly follow above two points. * Secondary…
Post: Virident vCache vs. FlashCache: Part 2
May 17, 2013 By 3 Comments
… of data (32 tables, 10M rows each) and a 4GiB buffer pool…different dirty-page ratios on device performance, since this is the only parameter which can be reliably varied between the two…=0 –percentile=95 \ –mysql-user=root –mysql-socket=/tmp/mysql.sock –mysql-table-engine=innodb \ –…
Post: MySQL Indexing Best Practices: Webinar Questions Followup
August 16, 2012 By 4 Comments
… used to join the two tables? A: The question in this case is how MySQL will execute the join… index and when go to Table1 to lookup row by primary key when you do not need …: Is there a difference between “`id` = 5″ and “`id` IN (5)” regarding indexes and performance? A: Recent MySQL versions are …
Post: How to recover deleted rows from an InnoDB Tablespace
February 20, 2012 By 4 Comments
…those deleted rows from the ibd file and import them into the database. The time between the deletion of rows and… 0-26 0-27 In this case, there are two indexes with the IDs 0-26 and 0-27…SCHEMA that can help us to find the different indexes and types. mysql (information_schema) > select i.INDEX_ID, i…
Post: Dynamic row format for MEMORY tables
September 6, 2011 By 5 Comments
… (also known as HEAP) in MySQL has been one of the …of the row. If there were any variable-length column in between them, …row format (DRF): Insertions in 900 seconds: 25949631 (0.05% slower). VmPeak: 6267700 kB Two…different number of rows inserted). In the second test we check if the dynamic row…
