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jacen6678
10-20-2003, 01:37 AM
When joining 2 indexed tables in MySQL, how many indexes are used? Lets assume for simplicity that we are joining 2 identical tables.

SELECT * FROM (a INNER JOIN b ON a.a_id=b.a_id)

Can MySQL use both indexes? Or can it only use one index?

PS - I realize that this isn;t a MySQL board. But, this is the best board that I have found and I have never gotten a wrong answer here. Apologies for posting something off topic.

pyro
10-20-2003, 07:11 AM
Not 100% sure what you are asking, but this might help: http://www.mysql.com/doc/en/MySQL_indexes.html