----- Original Message ----- > From: "Anupam Karmarkar" <sb_akarmar...@yahoo.com> > > select * from XYZ where key = 123; > > Now if i have to load data feed of 10 million once in week i need to > consider loading time also
Yes, On InnoDB you can't disable the primary key, as the data is index-organized. The reason why the primary key select is so fast, is also the reason why the data load is so slow :-p Now, if you really only need to check the existence of a single value, you can just import that value from the csv, and ignore all other fields - that should speed up the data load quite a bit. I just did a load of 10 million integers into a MyISAM, an InnoDB and a Memory table with just the integer field. Load times were respectively 35.18, 110.90 and 61.05 seconds from a local file; on all three tables primary key select (with sql_no_cache even) was pretty much instantaneous (0.01 seconds). I didn't test selects under parallel load, though. Make sure your key cache can hold all your indices. That way, pure-index selects should never go to disk once the index is cached. You may also consider taking that particular functionality out of MySQL altogether: have a look at Memcached, an in-memory key/value store. It's insanely efficient at single key lookups, and has a lot less overhead than SQL for that purpose. It's typically used for caching key/value pairs for webservers (like session variables and whatnot) but may be well-suited for your purpose, too. -- Bier met grenadyn Is als mosterd by den wyn Sy die't drinkt, is eene kwezel Hy die't drinkt, is ras een ezel -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/mysql?unsub=arch...@jab.org
