Meaning of SHOW TABLE STATUS info? (Was: How to find most recently added table in a database)

[Basil Hussain]

Hi all,

> "SHOW TABLE STATUS" has a "Create_Time" column.

I must've missed this in the manual. It's really quite useful and revealing.
So, I have a question about a bit of info it provides.

I see that the 'Data_free' column shows the (to quote from the manual)
"number of allocated but not used bytes". I ran it on a couple of databases
on my MySQL server and saw that this column showed a fairly large number for
some frequently updated tables. For example, one table that gets a batch of
thousands of records deleted and imported into it every day showed 77,004
bytes unused.

Firstly, if there is a reasonable amount of bytes unused, would this
indicate that the table needs to have OPTIMIZE TABLE run on it, or is it
nothing to worry about?

Secondly, what would be a reasonable figure be in order to make it worth
optimising?

Regards,

------------------------------------------------
Basil Hussain (basil.hussain@stripped)