Duplicate indexes and redundant indexes
Posted by peter
About every second application I look at has some tables which have redundant or duplicate indexes so its the time to speak about these a bit.
So what is duplicate index ? This is when table has multiple indexes defined on the same columns. Sometimes it is indexes with different names, sometimes it is different keywords used to define the index. For example it is quite frequite to see something like
PRIMARY KEY(id), UNIQUE KEY id(id), KEY id2(id)
del.icio.us
digg