… am using wordpress and drupal, and i converted databases from MyISAM to InnoDB, mysql tunning script gives below results for temp table… to reduce the number of disk-based temporary tables Note! BLOB and TEXT columns are not allow in memory tables. If…
Post: MySQL Prepared Statements
August 2, 2006 By 21 Comments
…about archiving best performance in your application using MySQL you should learn about prepared statements. These …means not only data does not need to be converted back and forth but you also save …copying Avoid SQL Injection Save memory on handling blobs There are also drawbacks and chewats of …
Comment: When should you store serialized objects in the database?
January 22, 2010 By 47 Comments
… does serialized blobs. YMMV, but I’m a little worried that with ‘Broken Window Theory’ that prototype never gets converted to columns… objects, I loose all my tools I’m used to (mysql cli, etc). I then have to create new tools (which… message system’ to convert everything over to E-Blob. That’s a mistake. My message here is that E-Blob is okay, but…
Post: Innodb row size limitation
April 7, 2011 By 12 Comments
…InnoDB; Now you insert some test data into it: mysql> INSERT INTO example -> VALUES ( ->Â Â NULL, ->Â …see http://www.mysqlperformanceblog.com/2010/02/09/blob-storage-in-innodb/ for further reference). It’… possible that you hit this error after converting from a native language character set to utf8…
Post: What exactly is read_rnd_buffer_size
July 24, 2007 By 4 Comments
… fields which are being length can be converted to fixed size (basically everything but BLOB/TEXT) MySQL can use read_rnd_buffer to… accessed in pretty much random row pointer (typically physical) order. MySQL takes bunch of pointers from sort_buffer (just enough so… fetching rows by pointers quickly For me this means since MySQL 4.1 this option is used in narrow range of…
Comment: Using CHAR keys for joins, how much is the overhead ?
July 5, 2007 By 18 Comments
… data.. Before MySQL 5.0.3, a CHAR or VARCHAR column with a length specification greater than 255 is converted to the… given length. For example, VARCHAR(500) is converted to TEXT, and VARCHAR(200000) is converted to MEDIUMTEXT. Similar conversions occur for BINARY and VARBINARY, except that they are converted to a BLOB type
Post: TMP_TABLE_SIZE and MAX_HEAP_TABLE_SIZE
January 19, 2007 By 17 Comments
… increase tmp_table_size to appropriate value and avoid using blob/text columns which force table creation on the disk because… it will be converted to MyISAM. To make things more confusing this is not what you would read in MySQL manual as… the tmp_table_size system variable. * MEMORY tables are never converted to disk tables. To ensure that you don’t accidentally…
Comment: How much overhead is caused by on disk temporary tables
August 17, 2007 By 26 Comments
… cases when BLOB/TEXT can’t be used because I expect them to have similar overhead (though I can try converting this column to TEXT to see how long time changes) There is another reason – MySQL only allows you…
