Monthly Archives - May 2006

InnoDB memory usage

There are many questions how InnoDB allocates memory. I’ll try to give some explanation about the memory allocation at startup.
Some important constants:
NBLOCKS=count of block in innodb_buffer_pool = innodb_buffer_pool_size / 16384
OS_THREADS= if (innodb_buffer_pool_size >= 1000Mb) = 50000
else if (innodb_buffer_pool_size >= 8Mb) = 10000
else = 1000 (it’s true for *nixes, for Windows there is a bit […]

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MySQL INSERT ON DUPLICATE KEY UPDATE and counters

MySQL INSERT ON DUPLICATE KEY UPDATE is very powerful but often forgotten MySQL feature. It was introduced in MySQL 4.1 but I still constantly see people unaware of it.
Myself I like this feature big deal because it is designed in truly MySQL style – very efficient solution for frequent task while keeping it beautiful […]

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Jeremy Cole on MySQL Replication

Jeremy Cole recently posted very nice post about MySQL Replication Performance. There are however few points I should comment on.

Jeremy Speaks about MyISAM and Innodb in the same terms, in fact they are quite different for Replication. As you probably know MyISAM uses buffered IO so if master crashes you’re out of sync […]

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