Hi So Just running a basic query I get returned the following :
table,type,possible_keys,key,key_len,ref,rows,Extra, Products,ALL,,,,,9884,where used, Therefore, I assume "*ALL*" is the worst possible type and should look at adding a an index to this particular field ? Cheers Neil On Fri, Jul 9, 2010 at 3:31 PM, mos <mo...@fastmail.fm> wrote: > At 12:43 AM 7/9/2010, you wrote: > >> On Fri, Jul 9, 2010 at 7:30 AM, Neil Tompkins >> <neil.tompk...@googlemail.com>wrote: >> >> > >> > Should we be looking to create a index for all fields that we might be >> > perform a select condition in a where clause for ? >> > > Neil, > Keep in mind that the more indexes you add to a table, the slower your > inserts will become because it needs to maintain the indexes. I would only > consider adding indexes to the slow queries. You can use the Explain on your > Select statement to see which indexes are being used. See > http://www.databasejournal.com/features/mysql/article.php/1382791/Optimizing-MySQL-Queries-and-Indexes.htmfor > an explanation on how to use EXPLAIN. > > BTW, if you are indexing text columns, you may want to look at FullText > indexing. > > Mike > > > > > It's a bit of trial and error, you have to weight the number of times you >> select based on a potential index vs. the impact that index might have for >> the amount of updates you do on the table. >> >> Generally speaking, though, it's indeed a good idea to find the >> most-frequently used where-clauses and index them. >> >> >> -- >> 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=neil.tompk...@googlemail.com > >
