Re: create index nologging does not improve performance

Jonathan Lewis doodled thusly:

>
>The redo log DOES contain an image of the index,
>in a form that is close to the actual index blocks.
>I think you're thinking of an export file containing just
>the "create index" command.

Ooops sorry, dunno where my mind was. Yes, of course. The output phase of the index creation is registered in the redo log. So are any changes to the index blocks as a result of updates/inserts later on. Otherwise the redo would not be able to perform its function of recovering the database in case of system failure.

>this - if read/write is the bottleneck serially, and if the
>sort_area_size is so small that sharing the job between
>two slaves still leaves multiple merges, the I/O contention
>is likely to get much worse.
>

This is very interesting. Must try it out. Thanks for this one.

Cheers
Nuno Souto
nsouto_at_optushome.com.au.nospam Received on Sun Apr 14 2002 - 06:48:32 CDT