Ah. Now I see the block# incrementing by one. (Thank you, Keith Moore, for
spotting that.)
Cary Millsap
Method R Corporation
Author of *Optimizing Oracle Performance <http://amzn.to/OM0q75>*
and *The Method R Guide to Mastering Oracle Trace Data, 3rd edition
<https://amzn.to/2IhhCG6+-+Millsap+2019.+Mastering+Oracle+Trace+Data+3ed>*
On Wed, Jan 22, 2020 at 8:41 AM Cary Millsap <cary.millsap@xxxxxxxxxxxx>
wrote:
Hi Chris,
What in your trace file is giving you the idea that the process is doing
1-block reads?
Cary Millsap
Method R Corporation
Author of *Optimizing Oracle Performance <http://amzn.to/OM0q75>*
and *The Method R Guide to Mastering Oracle Trace Data, 3rd edition
<https://amzn.to/2IhhCG6+-+Millsap+2019.+Mastering+Oracle+Trace+Data+3ed>*
On Tue, Jan 21, 2020 at 6:01 PM Chris Taylor <
christopherdtaylor1994@xxxxxxxxx> wrote:
So we use an ADG standby db for reporting and we've got some problem SQLs
that I'm putzing around with because they work fine in all our other
non-standby databases.
Looking deeper into the tracefile, I see it doing 1 block at a time reads
, even though it says its reading 128.
It does this on both of our ADG Standby Databases which are on completely
different hardware.
WAIT #140196872952648: nam='db file scattered read' ela= 1588 file#=4097
block#=579715946 blocks=128 obj#=-39778567 tim=17263910670242
WAIT #140196872952648: nam='db file scattered read' ela= 1495 file#=4097
block#=579715947 blocks=128 obj#=-39778567 tim=17263910672065
WAIT #140196872952648: nam='db file scattered read' ela= 1671 file#=4097
block#=579715948 blocks=128 obj#=-39778567 tim=17263910674042
WAIT #140196872952648: nam='db file scattered read' ela= 1094 file#=4097
block#=579715949 blocks=128 obj#=-39778567 tim=17263910675443
File# in this case is the TEMP Segment from V$SORT_SEGMENT.
If I check V$SORT_SEGMENT, I don't see any object that has that many
blocks.
I'm considering dropping & recreating the TEMPFILE in the two standby
databases to see if that will resolve the issue.
Anyone seen anything like that before?
Chris
