Monthly Archives - January 2009

Funniest bug ever

Recently my attention was brought to this bug which is a nightmare bug for any consultant.
Working with production systems we assume reads are reads and if we’re just reading we can’t break anything. OK may be we can crash the server with some select query which runs into some bug but not […]

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iiBench with deletes

We modified the iiBench benchmark to perform deletions as well as insertions, and compared InnoDB to Tokutek’s Fractal TreeTM storage engine, both running on MySQL 5.1. I’ll post the revised iiBench tarball soon.
Here is what the performance looks like:

The iiBench-with-deletions benchmark works as follows. The benchmark employs a fact table with an […]

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The perils of InnoDB with Debian and startup scripts

Are you running MySQL on Debian or Ubuntu with InnoDB? You might want to disable /etc/mysql/debian-start. When you run /etc/init.d/mysql start it runs this script, which runs mysqlcheck, which can destroy performance.
It can happen on a server with MyISAM tables, if there are enough tables, but it is far worse on InnoDB. […]

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Another scalability fix in XtraDB

Recent scalability fixes in InnoDB and also Google’s and your SMP fixes almost made InnoDB results acceptable in primary key lookups queries, but secondary indexes were forgotten for some time. Now having Dell PowerEdge R900 on board (16CPU cores, 16GB RAM) I have some time for experiments, and I played with queries

Shell

SELECT name […]

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