Index

[Piranha]

I know that indexes are used to speed up the queries. But does to many indexes slow it down instead? As an example I have the following table:

id  int(11)           auto_increment              primary key
groupid  int(11)      Null  

active  int(11)       Not null                

minPH  double         Not null               

maxPH  double         Not null             

minTemp  double       Not null      

maxTemp  double       Not null             

difficulty  int(11)   Not null             

description  text     Null

I use all columns except description to search, but normally (at least 9 times out of 10) it is only the id that is used. Should I make the other columns indexed as well (except description that is) or will it backfire by doing the queries where I only use id slower?

[pete_bisby]

Too many indexes on a table can slow down the performance - it does depend on how many INSERTS/UPDATES are going to be performed on the table, also.

If the table is going to be constantly updated, I would tend not to use the indexes. If it is a table that is populated once, or limited UPDATES/INSERTS carried out, then add the indexes.