…then uses the MRR interface (which I explained in my previous post) to lookup the rows in table2. …will operate is that first a hash table will be created based on the columns of table t1 that are two be…the best result for MariaDB 5.5 for in-memory workload. I intend to run tests to see what specific…
Post: Testing STEC SSD MACH16 200GB SLC
April 25, 2012 By 7 Comments
… activity. The results for random read case: Very stable throughput on line 222 MiB/sec To understand better what kind of response… MySQL questions – I will be giving a webinary “MySQL and SSD” on May-9. It will be the same as my talk on Percona Live MySQL Conference 2012, if you did not attend my talk – you…
Post: Multi Range Read (MRR) in MySQL 5.6 and MariaDB 5.5
March 21, 2012 By 10 Comments
…let’s take a look at what this optimization actually is and what benefits it brings. Multi Range…benchmarks, to see the difference in numbers. Benchmark results For the purpose of this benchmark, I have… to cover it here, but will cover it in my next post which will be on Block Access Join Algorithms….
Post: Testing Samsung SSD SATA 256GB 830 - not all SSD created equal
April 25, 2012 By 10 Comments
… an internal cache or something. To understand better what kind of response time we should expect, I …320 (some results for Intel 320). If you are interested more in SSD and MySQL questions – I will be giving a webinary “MySQL and SSD” on May-9. It will be the same as my talk on …
Post: Troubleshooting MySQL Memory Usage
March 21, 2012 By 3 Comments
…*************************** SESSION_ID: 7234 TABLE_SCHEMA: test TABLE_NAME: my ENGINE: InnoDB NAME: #sql516_1c42_2 TABLE…they will be gone when connection is closed, other correspond to global memory allocation and will result … allowing us to see directly for what purpose memory is allocated and so …
Post: Index Condition Pushdown in MySQL 5.6 and MariaDB 5.5 and its performance impact
March 12, 2012 By 12 Comments
… Now let’s take a look briefly at what this enhancement actually is, and what is it aimed at. Index Condition Pushdown… after the part on which range condition is applied cannot be used for filtering records. For example, suppose you have a…
Post: MySQL 5.5.8 - in search of stability
January 3, 2011 By 11 Comments
… some of my conclusions, so I decided to take a more detailed look at my findings. Let me show you my results. Article [1… now we are limited by innodb_max_dirty_pages_pct, what will be the result if we try to increase it to 70% ? It… log space. The 15-minute average result for this test is 55073.06 NOTPM. What can be the reason? Let’s try a…
Post: Enum Fields VS Varchar VS Int + Joined table: What is Faster?
January 24, 2008 By 27 Comments
… happens to be data we had available for tests) Two important notes about this table before we get to results – this is…. In many cases size difference will be significantly less. All tests are runned 1000 times and the result time is average from those… ID. Next test was a result of my curiosity. I’ve tried to order results by states. 1) Results for ENUM: select SQL_NO…
Post: What's required to tune MySQL?
July 27, 2011 By 4 Comments
…serendipitous call (thanks!) yesterday asking what would be needed to tune[1] a database for better …will need more than simply looking at your my.cnf file. It’s sometimes possible to look at the my… activity that can be done endlessly, with little definition or quantification of results. I prefer to …
Post: MySQL: what read_buffer_size value is optimal ?
September 17, 2007 By 25 Comments
… results with sort performance and today I’ve discovered even read_buffer_size selection may be less than obvious. What… set this variable to some high value. Sample my.cnf values on large memory sizes recommend 1M …of rows to reach 4G in size so workload will be IO bound on the box with 2GB of memory…
