Search Results for: fast storage

Full table scan vs full index scan performance

Earlier this week, Cédric blogged about how easy we can get confused between a covering index and a full index scan in the EXPLAIN output. While a covering index (seen with EXPLAIN as Extra: Using index) is a very interesting performance optimization, a full index scan (type: index) is according to the documentation the 2nd […]

Percona-XtraDB-9.1: released and new coming features

Recently Alexandr announced new Percona-XtraDB-9.1 release, and now it is good time to summarize features we have and what is expected soon. This release contains long waited features from 5.0: extended slow.log USER/TABLE/INDEX/CLIENT_STATISTICS + THREAD_STATISTICS ( coming in release-10) Extended slow.log is now even more extended, there is additional information for each query:

That […]

5.0.75-build12 Percona binaries

After several important fixes to our patches we made binaries for build12. Fixes include: Control of InnoDB insert buffer to address problems Peter mentioned http://www.percona.com/blog/2009/01/13/some-little-known-facts-about-innodb-insert-buffer/, also check Bug 41811 to see symptoms of problem with Insert buffer. http://www.percona.com/docs/wiki/patches:innodb_io_patches * innodb_flush_neighbor_pages (default 1) – When the dirty page are flushed (written to datafile), this parameter determines […]

How much overhead DRDB could cause ?

I was working with the customer today investigating MySQL over DRBD performance issues. His basic question was why there is so much overhead with DRBD in my case, while it is said there should be no more than 30% overhead when DRBD is used. The truth is – because how DRBD works it does not […]

Worrying about the ‘InnoDB: detected cycle in LRU for buffer pool (…)’ message?

If you use Percona Server 5.5 and you have configured it to use multiple buffer pool instances than sooner or later you’ll see the following lines on the server’s error log and chances are you’ll be worried about them:

Worry not as this is mostly harmless. It’s becoming a February tradition for me (Fernando) […]

Is MySQL’s innodb_file_per_table slowing you down?

MySQL’s innodb_file_per_table is a wonderful thing – most of the time. Having every table use its own .ibd file allows you to easily reclaim space when dropping or truncating tables. But in some use cases, it may cause significant performance issues. Many of you in the audience are responsible for running automated tests on your […]