… hash=crc32(‘string‘) AND string=’string‘ The other thing you need to consider is string comparison in MySQL is case insensitive by default while hash comparison will be done case sensitive unless you lowercase string before hashing…
Post: Cache Performance Comparison
August 9, 2006 By 74 Comments
… to publish his comparison of all caches anyway, I decided to check peak performance of all caches compared to MySQL Server, by… were running on same system. I used two baselines for comparison. First is speed of PHP Associative array. This is to… not do much of error control or other precausions like string escaping which you will need in real application. Also due…
Comment: MySQL Installation and upgrade scripts.
May 21, 2007 By 3 Comments
…, “check for upgrade” did not trigger table repairs (bad, varchar string comparison with trailing spaces might return different from expected results), no… tables, performance problems while table is updated by PK = empty string (actially is was an application side problem, but at least… present time I decided to upgrade to 5.0.36sp1 (MySQL Enperprise) it seems to be the most stable release, it…
Post: Efficient Boolean value storage for Innodb Tables
April 23, 2008 By 6 Comments
… which can store one of two values – NULL or Empty String. Lets see how these 3 different table format look in… (IS ” would not work) or you can use Null-Aware comparison operator: mysql> select count(*) from cbool where c1NULL; +———-+ | count(*) | +———-+ | 1048576 | +———-+ 1…
Comment: Fixing column encoding mess in MySQL
January 27, 2011 By 32 Comments
… bin2hex… what would I do with hex data? and some comparison functions and that’s all. What would I compare them… in MySQL: SET field = REPLACE(field, ‘•’, ‘•’); MySQL said it happily replaced the string in lots of fields (and searching that string…
Post: Using CHAR keys for joins, how much is the overhead ?
June 18, 2007 By 18 Comments
… someone curious, it did not really change beside key lengths: mysql> explain select sum(t1.i+t2.j+length(t2.c… this to shorten some internal buffers MySQL has to allocate for key comparison as well as have comparison function significantly faster. The reason… for Innodb. Finally I decided to check if using longer strings slows down things significantly and so I replaced all numbers…
Post: Add an option to Fail on Innodb Initialize failure, Please ?
October 11, 2007 By 9 Comments
… far from improving user experience. It is worth to note MySQL 5.0 introduces STRICT option which will makes error control… Enterprise users – so instead of cutting the string lengths or converging NULLs to zeros MySQL can be tuned to abort such statements… to add one I think. Note if we use typical comparison of Storage Engines to File Systems – you have an option…
