… painful troubleshooting tasks with MySQL is troubleshooting memory usage. The problem usually starts like this – you have configured MySQL to use… memory than you would expect, causing swapping or other problems. This simple problem on the surface becomes challenge with MySQL because there… MySQL to identify potential causes. Is it working with large blobs ? Using user variables ? Prepared Statements ? memory tables ? In a lot…
Post: MySQL Blob Compression performance benefits
January 11, 2008 By 17 Comments
… to keep it compressed. Unfortunately MySQL does not provide compressed BLOB/TEXT columns (I would really love to have COMPRESSED attribute… network traffic a bit, though this is not generally the problem. Compression on the server gives you ability to do some… and performance gains, especially for Innodb tables. With Innodb tables BLOB gets its own page (allocated outside of clustered index) if…
Post: Heikki Tuuri Innodb answers - Part I
October 26, 2007 By 17 Comments
… 8100 bytes InnoDB will not allocate additional space for blobs, even if each blob is larger than 768. 2. InnoDB will allocate… or 2 often solves your thrashing problem. PZ: Values 1,2 may solve your thrashing problem but also will limit innodb to… are some benchmarks we did. Q24: INNODB has typically had problems scaling on multicore boxes. The new quad core CPUs from…
Post: Bug#12704861
November 20, 2011 By 1 Comment
… release notes about what could potentially be a very serious problem that is fixed in MySQL 5.1.60. I’ll… fix. The problem that this function was trying to address was that when we did mtr_commit() the BLOB writes before the… of a mini-transaction allocated (nonfree=TRUE) before storing the BLOBs, or freed (nonfree=FALSE) before committing the mini-transaction. btr…
Post: Innodb row size limitation
April 7, 2011 By 11 Comments
… version specific, see http://www.mysqlperformanceblog.com/2010/02/09/blob-storage-in-innodb/ for further reference). It’s worth mentioning… uses a 20 byte pointer for variable length types, this problem just goes away. Limit the size of variable length columns… up to that fields’ maximum allowed value. So, if your problem domain allows you to limit the size of these fields…
Post: Falcon Storage Engine Design Review
January 12, 2007 By 19 Comments
… great. Huge indexes is where large portion of Innodb performance problems come however. We should however see how “compact” they would… buffer”. Jim does not believe this is the problem but I remember having problem not the once and twice before Innodb Double… often. [+] Blob handling optimizations Jim loves BLOBs as his own child, so Falcon is optimized in Blob handling for example having direct blob writes…
Comment: Blob Storage in Innodb
February 17, 2010 By 13 Comments
… of files in a filesystem is bad. I ran into problems having many thousands (millions?) of files, where I ran out… for indexing or searching. If you think you need multiple blob columns, then as Peter suggested, consider combining them into 1 blob and on the application side splitting up the blobs. That might not so easy either…
Post: My Innodb Feature wishes
May 4, 2006 By 30 Comments
… outside of it. The other item with blobs – currently if I’m not mistaken blobs are stored each in its own “segment… is so bad I will list it. Basically Innodb has problems scaling both with large number of active threads and with… it is too bad even with 4 concurrent queries). The problem seems to be at least partially due to global mutexes…
Post: Data Corruption, DRBD and story of bug
November 29, 2010 By 6 Comments
… database in trash state just executing update on row with blob and rolling back transaction twice ( on the same row) The… innodb_force_recovery=3 and mysqldump your data. What makes problem even worse is that InnoDB does not report tablename, so… Availability. And just to be clear, it is not DRBD problem, DRBD basically can’t help if there is possibility that…
Comment: Falcon Storage Engine Design Review
January 12, 2007 By 19 Comments
… which can’t really be changed in many cases. Performance problems tend to appear then application is in production Ordered data… memory (row cache) there is no problem but if it does not this is there problems start. Using Index: Again you look… more, or you may throw an error. Blob Handling: Just regarding your comment about blob materialization – Innodb also will only read the…
