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Hi Dicky,
It is perfectly normal for 'latch free' waits to timeout. Are you saying that there were a large number of these waits at this time? If so, on which latch type (V$LATCH)?
A useful way to diagnose such problems is to use a script such as the session_times.sql on my web site (1st URL below). That will tell you what your session was waiting for.
Regards,
Steve Adams
http://www.ixora.com.au/ http://www.oreilly.com/catalog/orinternals/ http://www.christianity.com.au/
On Sat, 13 Nov 1999 01:17:11 +0800, "ccdicky in hotmail" <ccdicky_at_hotmail.com> wrote:
>Hi there,
>
>Select 50,000 rows (100 bytes per row) from table A and then insert into
>table B taking about 15mins to get done. However, it takes less than 1min
>if spooling to a file. Even table B contain an index on date field, it
>still doesn't make sence to me. Since the both tables are stored in
>different tablespaces with different disks. In addition, there is no any
>other running process during the insertion.
>
>Therefore, during insertion, I tried to query a number of performance views
>and discovered that the "total_waits" of 'LATCH FREE' event is exactly same
>as the "total timeouts" of that in V$SESSION_EVENT view. Is it the reason
>why the insertion is running so slow? And what is the meaning of this
>event? If not, any suggestion to find out the real cause.
>
>Any pointer would be appreicated. Thanks!
>
>Dicky
>
>
>
Received on Fri Nov 12 1999 - 16:13:32 CST