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Purge Thread Spiral of Death

 | June 10, 2010 |  Posted In: Insight for DBAs, MySQL

I just wrote a large post on reasons for innodb main tablespace excessive growth and I thought it would make sense to explain briefly of why it is so frequently you have purge not being the problem at all and when out of no where you can see purge thread being unable to keep up […]

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Reasons for run-away main Innodb Tablespace

 | June 10, 2010 |  Posted In: Insight for DBAs, MySQL

So you’re running MySQL With innodb_file_per_table option but your ibdata1 file which holds main (or system) tablespace have grown dramatically from its starting 10MB size. What could be the reason of this growth and what you can do about it ? There are few things which are always stored in main tablespace – these are […]

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 | June 8, 2010 |  Posted In: Insight for DBAs, MySQL

Quite frequently I see people confused what table locks reported by SHOW INNODB STATUS really mean. Check this out for example:

This output gives us an impression Innodb has taken table lock on test/t1 table and many people tend to think Innodb in fact in some circumstances would abandon its row level locking and […]

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Making Deletions Fast, by Avoiding Disk Seeks

 | June 8, 2010 |  Posted In: Tokutek, TokuView

In my last post, I discussed how fractal tree data structures can be up to two orders of magnitude faster on deletions over B-trees. I focused on the deletions where the row entry is known (the storage engine API handler::delete_row), but I did not fully analyze how MySQL delete statements can be fast. In this […]

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PBXT in tpcc-like benchmark

 | June 2, 2010 |  Posted In: Benchmarks, MySQL

Finally I was able to run PBXT 1.0.11 pre-GA in tpcc-like workload, apparently there was bug with did not allow me to get the result earlier, and I am happy to see that PBXT team managed it. For initial runs I took tpcc 100 warehouses ( about 10GB of data) which fully fits into memory […]

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Security fixes for MySQL 4.0 and 4.1

 | June 2, 2010 |  Posted In: MySQL, Percona Software

In Percona Server security fix releases I mentioned patches for MySQL 4.0 and 4.1. I am happy to announce that released patches for MySQL 4.0 and MySQL 4.1 under GPL license and you can get them from our Launchpad: for 4.0: lp:~percona-dev/percona-patches/4.0.30 ( or ) for 4.1: lp:~percona-dev/percona-patches/4.1.24 ( or Fixed bugs: […]

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Color code your performance numbers

 | June 2, 2010 |  Posted In: Insight for Developers, MySQL

When analyzing how good or bad response time is it is not handy to look at the averages, min or max times – something what is easily computed using built in aggregate functions. We most likely would like to see some percentile numbers – 95 percentile or 99 percentile. The problem is computing these in […]

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