… case is random write asynchronous 8 threads IO, the test is done just after a secure erase operation on the card. The card is… is getting closer to level of PCIe cards. Of course PCIe still provides better numbers, but the question is how much MySQL can use. In his keynote Mark Callaghan mentioned that Fusion-io cards they use are highly underutilized…
Comment: ext4 vs xfs on SSD
May 3, 2012 By 23 Comments
… and how much of their recommendation comes from the days of ext2/ext3. So I decided to use sysbench …to do another benchmark. What I found with XFS is that, to my great surprise, changing the number …that Dave was referring to above. Disclaimer: I’m just someone who runs their own benchmarks, and am …
Comment: ext4 vs xfs on SSD
April 25, 2012 By 23 Comments
… think I should use to recommend that or another product/filesystem? For me – amount of bugs (how stable it is) is one of most… can use today, now in production deployment. How stable will be product is 2 years is rather theoretical question for personal curiosity. There is big… months. Following your logic, it seems I just should go ahead and recommend to use btrfs to everyone, because it has so…
Post: Multi Range Read (MRR) in MySQL 5.6 and MariaDB 5.5
March 21, 2012 By 10 Comments
…is choosing the query execution plan, is not sufficiently tuned and it is recommended to turn this off. The query used is… workload Now let’s see how effective is MRR when the workload is IO bound. For the …read_aheads. Another thing to take away is that MariaDB is just a bit slower as compared to …
Post: Index Condition Pushdown in MySQL 5.6 and MariaDB 5.5 and its performance impact
March 12, 2012 By 12 Comments
… by one. So in the same way this blog post is aimed at a new optimizer enhancement Index Condition Pushdown (ICP… take a look briefly at what this enhancement actually is, and what is it aimed at. Index Condition Pushdown Traditional B-Tree… index parts after the part on which range condition is applied cannot be used for filtering records. For example, suppose you have…
Post: Troubleshooting MySQL Memory Usage
March 21, 2012 By 3 Comments
… get information of how much memory connection uses and for which purposes it is allocated. Reducing various per connection variables is how you can test… more insight about how memory is used. I would note though the output is a bit confusing as “Total Memory Allocated” is really not the… it is very small blocks, it should be just swapped out and when never needed again. So if you see swap file used…
Post: Join Optimizations in MySQL 5.6 and MariaDB 5.5
April 4, 2012 By 2 Comments
… more about these variables here. The query used is: select l_orderkey, sum(l_extendedprice * (1 – … In-memory workload Now let’s see how effective are the join optimizations when the…is close, yet slower by ~10s. Another thing that is important to know is that, just increasing the join_buffer_size is…
Post: How FLUSH TABLES WITH READ LOCK works with Innodb Tables
March 23, 2012 By 20 Comments
… this statement to complete. Here is example how it can look: mysql> show processlist; +——-+——+———–+———-+———+——+————————-+—————————–+———–+—————+———–+ |… or another. If you’re just using Innodb tables and you’re …
Post: How We Got Here
April 9, 2012 By 6 Comments
… event is inclusive, with all vendors and competitors welcomed on an equal footing. The event balances community, business, and technology, not just… none. Attendees will hear from people who use MySQL in production systems and know how to operate it and develop against it… qualified to talk about how MySQL works in practice. Sponsors will have an engaged and active audience that is genuinely interested in…
Comment: Introducing new type of benchmark
February 25, 2012 By 16 Comments
… decreases when the server is not behaving acceptably. It uses an exponentially decaying weighted moving average to determine how long of a window to do the 99% measurement. This is kind… hour, so it varies the arrival rate until the server is just barely responding acceptably, and eventually reports the throughput. The inputs…
