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INFORMATION_SCHEMA tables in the InnoDB pluggable storage engine

 | May 24, 2008 |  Posted In: Insight for DBAs

Much has been written about the new InnoDB pluggable storage engine, which Innobase released at the MySQL conference last month. We’ve written posts ourselves about its fast index creation capabilities and the compressed row format, and how that affects performance. One of the nice things they added in this InnoDB release is INFORMATION_SCHEMA tables that […]

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Dangerous command

 | May 20, 2008 |  Posted In: Insight for DBAs

Remembering that I did RENAME DATABASE in MySQL 5.1.21 and found it useful I tried it with 5.1.24 (I was playing with 20GB InnoDB database, so dumping is not fastest way) and all my tries finished with “Syntax error”. So RTMF and documentation says “This statement was added in MySQL 5.1.7 but was found to […]

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Wanted: Better memory profiling for MySQL

 | May 18, 2008 |  Posted In: Insight for DBAs

Quite frequently I would log in to customers system and find MySQL using too much memory. I would look at memory consumed by Innodb (it is often higher than innodb_buffer_pool_size) substract memory used by other global buffers such as query_cache_size and key_buffer and will in many cases see some mysterous memory which I can’t really […]

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Concurrent inserts on MyISAM and the binary log

 | May 14, 2008 |  Posted In: Insight for DBAs

Recently I had an interesting surprise with concurrent inserts into a MyISAM table. The inserts were not happening concurrently with SELECT statements; they were blocking and the process list was filling up with queries in Locked status. My first thought was that the customer had deleted from the table, which leaves “holes” in the middle […]

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Learning about MySQL Table Fragmentation

 | May 1, 2008 |  Posted In: Insight for DBAs

Recently I was working with the customer who need quick warmup – to get Innodb table fetched in memory as fast as possible to get good in memory access performance. To do it I run the query: “SELECT count(*) FROM tbl WHERE non_idx_col=0” I use this particular form of query because it will do full […]

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MySQL Replication vs DRBD Battles

 | April 28, 2008 |  Posted In: Insight for DBAs

Well these days we see a lot of post for and against (more, more) using of MySQL and DRBD as a high availability practice. I personally think DRBD has its place but there are far more cases when other techniques would work much better for variety of reasons. First let me start with Florian’s comments […]

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