Re: adding then removing index produces different query results

[Sebastian Mendel]

mysql mysql schrieb:
> Can anyone explain the following?   I encountered the following very strange
> behaviour while attempting to optimize a query (more details are provided
> later on for those interested):
> 
> 1) execute query
> takes 2 minutes
> 2) add index
> 3) execute same query
> takes 11 seconds
> 4) drop index
> 5) execute same query
> takes 0.2 seconds and uses a different method of returning results from the
> original query in 1)
> 6) restart mysql
> 7) execute query
> takes 2 minutes

query cache, os cache, or some other cache

-- 
Sebastian