>> I have a very bit big database around 15 million in size, and the dump
>> file
>> is around 12 GB.
>>
>> While importing this dump in to database I have noticed that initially
>> query
>> response time is very slow but it does improves with time.
>>
>> Any suggestions to improve performance after dump in imported in to
>> database
>> will be highly appreciated!
>
> This is pretty normal. When the db first starts up or right after a
> load it has nothing in its buffers or the kernel cache. As you access
> more and more data the db and OS learned what is most commonly
> accessed and start holding onto those data and throw the less used
> stuff away to make room for it. Our production dbs run at a load
> factor of about 4 to 6, but when first started and put in the loop
> they'll hit 25 or 30 and have slow queries for a minute or so.
>
> Having a fast IO subsystem will help offset some of this, and
> sometimes "select * from bigtable" might too.
Maybe it's the updating of the the hint bits ?...