Hello,
I am using MySQL Server 3.23.56 on Redhat Linux 7.2 and having the following problem: When the tables of type MyIsam are copied, and I run a query on the tables created by copy – it takes awfully long as compared to when run on the original tables.

When we run the command “check table” and “repair table”, it takes around 10-15 seconds on some of the tables although “check table” returns everything ok. But after “repair table” is run on those tables, the query gets faster.

There’s one table that has 10 indexes and 10,000 rows and the other table has 3 indexes and 500 rows. The query that gets slow has lot of left joins on these tables. I am not sure what’s causing the problem and how to fix it. Could anybody please help me.

Thanks,
Hitesh

Well, your original table probably has probably a lot of the index keys and records buffered... The fact that your "copy" tables becomes fast *after* a repair table is most likely a sign that the repair itself buffered a lot of your data...

Have you tried shutting down your server and performing the same test on your original table right after the server is brought up?

thanks for your reply, bstjean. I will perform the test that you mentioned and will let you know how it goes.

Thanks again,
hitesh