mysql Overhead

[alin19]

when i'm using a php query to delete a record from a mysql table,  i go in phpmy admin and i have a red line like this:

 

Space usage    Type  Usage

Data 3,436 B

Index 2,048 B

Overhead 64 B

Effective 5,420 B

Total 5,484 B

Optimize table Optimize table

 

and i have to press optimize table every time

why i get this?

 

[MadTechie]

Its probably to do with indexing..

 

if you use a join on a field thats not indexed, mysql will need to index that field (this slows it down), if you index that field it should stop the overhead and speed up the searches,