Monthly Archives - October 2011

Benchmarking Galera replication overhead

When I mention Galera replication as in my previous post on this topic, the most popular question is how does it affect performance.
Of course you may expect performance overhead, as in case with Galera replication we add some network roundtrip and certification process. How big is it ? In this post I am trying […]

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When EXPLAIN estimates can go wrong!

I have been working with a few customer cases and one interesting case popped up. The customer was facing a peculiar problem where the rows column in the EXPLAIN output of the query was totally off. The actual number of rows was 18 times more than the number of rows reported by MySQL in […]

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Understanding Indexing – NY Effective MySQL Meetup

At next week’s NY Effective MySQL Meetup, I will give a talk: “Understanding Indexing: Three rules on making indexes around queries to provide good performance.” The meetup is 7 pm Tuesday, October 11th, and will be held at Hive at 55 (55 Broad Street, New York, NY). Thanks to host Ronald Bradford for the […]

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Keep your MySQL backend online no matter what + TGIF Contest!

On Oct. 25th I will be presenting my conference session “Keep your MySQL backend online no matter what” at the Percona Live London Conference. Considering their is a variety of highly knowledgeable MySQL experts speaking at this event I wanted to give my talk a special plug so you won’t miss THIS knowledgeable MySQL […]

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When Does InnoDB Update Table Statistics? (And When It Can Bite)

An InnoDB table statistics is used for JOIN optimizations and helping the MySQL optimizer choose the appropriate index for a query. If a table’s statistics or index cardinality becomes outdated, you might see queries which previously performed well suddenly show up on slow query log until InnoDB again updates the statistics. But when does […]

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Write Optimization: Myths, Comparison, Clarifications, Part 2

In my last post, we talked about the read/write tradeoff of indexing data structures, and some ways that people augment B-trees in order to get better write performance. We also talked about the significant drawbacks of each method, and I promised to show some more fundamental approaches.
We had two “workload-based” techniques: inserting in sequential […]

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Percona Server 5.5.15 + Galera 21.1-beta2

Codership team published beta2 of MySQL 5.5.15 with Galera replication
https://launchpad.net/codership-mysql
and we made port to Percona Server:
source code:
lp:~percona-dev/percona-server/percona-server-galera-5.5.15
binaries for RedHat/CentOS 6:
https://www.percona.com/downloads/TESTING/Galera/Percona-XtraDB-Galera-5.5.15.tar.gz
What difference between Percona Server+Galera and MySQL 5.5.15 ?
First of course, Percona Server+Galera is based on our XtraDB engine.
Second, we provide wsrep_sst_xtrabackup script, which allows to use Percona XtraBackup for node provisioning.
Percona Server+Galera is still […]

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