Re: Two general MySQL questions

[KimSeong Loh]

A. table1 should have the least amount of (expected) results
Not sure about why you say this.


B. table1 should be have a good index
For the 1st table, index on the WHERE clause column, index on join column is not required.
example: select * from table1 inner join table2 on ... where table1.idx=123
This is to filter the rows in table1 first, reduce the nubmer of rows that need to be joined.


C. table2 should have a good index (with the join key in it???)
You definitely need this one, to have an index on the join column of the 2nd table to perform the join efficiently.