…->lock mutex. InnoDB uses single mutex per index, so when you run mixed read / write queries, InnoDB locks index for write operation and thus… some scanning by secondary key select queries and write queries at the same time. InnoDB again uses single global mutex for adaptive… and for two FusionIO cards coupled in RAID0 (which theoretically doubles througput).
Post: Index lock and adaptive search - next two biggest InnoDB problems
February 25, 2010 By 12 Comments
Post: Choosing innodb_buffer_pool_size
November 3, 2007 By 39 Comments
… proper innodb_buffer_pool_size and indeed I oversimplified things a bit too much, so let me write a bit better description. Innodb Buffer Pool is by far the most important option for Innodb Performance and it… Double Buffering – This is again very important for buffer pool size choice. You do not want OS to cache what Innodb is…
Post: Innodb Performance Optimization Basics
November 1, 2007 By 75 Comments
… effect especially on a lot of short write transactions. innodb_thread_concurrency=8 Even with current Innodb Scalability Fixes having limited concurrency helps… and default which is 8 is decent start innodb_flush_method=O_DIRECT Avoid double buffering and reduce swap pressure, in most…
Comment: Jeremy Cole on MySQL Replication
June 17, 2006 By 12 Comments
… “physical” log file which is called “double write buffer” to handle problem of partial page writes. The log file is structured differently it… their own logs. In MySQL 5.0 you can disable innodb_xa_support and you can get binary log possibly out of sync with innodb transactional log. However it will not make group commit to…
Comment: InnoDB Flushing: a lot of memory and slow disk
April 1, 2011 By 57 Comments
Patrick, It is mostly code things. Innodb Is not designed to flush clean pages from buffer pool … need to go to double write buffer ? Probably not, if so how can we write them but skip from being put to double write buffer.
Comment: InnoDB Flushing: a lot of memory and slow disk
March 31, 2011 By 57 Comments
Patrick, It is mostly code things. Innodb Is not designed to flush clean pages from buffer pool … need to go to double write buffer ? Probably not, if so how can we write them but skip from being put to double write buffer.
Comment: Innodb Double Write
March 31, 2011 By 24 Comments
…” is saved in the redo log. Unless you mean “partial write” will modify someting not saved in the redo log?? I mean, EVERY change are in the redo log entries. Partial write , in my mind, is that it failed to make some… I think I still didn’t understand innoDB , why it need “double write“? I am new to innoDB, not knowing any internal details, I…
Comment: Heikki Tuuri Innodb answers - Part I
October 27, 2007 By 19 Comments
… we frequently look into Innodb code ourselves and it is very well commented. You’re correct when Innodb does a flush it… two writes plus seek. Another interesting question which I should probably check is if there is any reordering happens during double write process, ie 128 pages are written to boulewrite buffer – are they sorted then for writing to original locations…
Comment: Innodb Double Write
August 4, 2006 By 24 Comments
…” is saved in the redo log. Unless you mean “partial write” will modify someting not saved in the redo log?? I mean, EVERY change are in the redo log entries. Partial write , in my mind, is that it failed to make some… I think I still didn’t understand innoDB , why it need “double write”? I am new to innoDB, not knowing any internal details, I…
Comment: Falcon Storage Engine Design Review
January 12, 2007 By 19 Comments
…, which hasn’t happened yet. It’s worth noting that InnoDB allows a transaction to overwrite changes that are not returned…, you can’t change it. No protection from partial page writes Interbase used to checksum pages, but calculating the checksum took…€™t even come close to working. With checksums, the InnoDB double page write might be a good thing to add, assuming that the…
