…, then the index you’re creating won’t be used for the optimization. Here’s an example with another schema: mysql> create table…: NULL rows: 4 Extra: Using filesort 1 row in set (0.00 sec) mysql> alter table t1 add index(id); Query OK, 4…: 4 Extra: Using filesort 1 row in set (0.00 sec) You can hint the optimizer: mysql> explain select * from t1 force index (id…
Comment: The ultimate tool for generating optimal my.cnf files for MySQL
August 20, 2008 By 34 Comments
… read this blog entry twice and still cannot see any hints regarding my.cnf tuning, only some trolling on how bad… a good table design, used good indexes and using good selects (which use these indexes in an optimized fashion)… specially since MySQL itself is so bad… if you have correct design, index and optimized queries. Innodb on the other hand (when used through MySQL) has some nifty features regarding…
Post: Analyzing air traffic performance with InfoBright and MonetDB
October 2, 2009 By 50 Comments
… field. After that load statement is: mysql -S /tmp/mysql-ib.sock -e “LOAD DATA INFILE …UPDATE (5-Oct-2009): James Birchall recommended to use hint COMMENT ‘lookup’ for fields in InfoBright that…indexes like InfoBright, but results are impressive. On drawbacks – the command line is weak ( I had to use…
Comment: When should you store serialized objects in the database?
January 22, 2010 By 47 Comments
…”when is it a good idea” cases. @Angelo – That indexing technique is described pretty well in the Friendfeed …serialized objects, I loose all my tools I’m used to (mysql cli, etc). I then have to create … equal). On Modeling – I’d say I probably hinted at that in saying “if the application really …
Comment: Multi Column indexes vs Index Merge
September 20, 2009 By 31 Comments
Peter, Did you ever do the same testing for MySQL 5.0.x instead of 5.1/5.4？ As in my website, the MySQL query optimizer in different version work quite differently and 5… sometimes I have to add some query hints to help 5.1 using the right index. Thus, until now, although new features in…
Comment: FusionIO 320GB MLC benchmarks
January 14, 2010 By 19 Comments
…BCNF to do random I/O. InnoDB secondary indexes on a denormalized table can generate a …improve join performance remember that all queries on MySQL are essentially single threaded (excluding for a …because of outer joins or hints, so just about any database which uses any joins can probably benefit…
