Comments for Dion Cho - Oracle Performance Storyteller

Comment on Interesting case of the restriction of global hints by Greg Rahn

Greg Rahn — Fri, 17 Dec 2010 18:43:21 +0000

The syntax you are using is invalid (v.t1, v.t2). You need to move the leading hint for t1, t2 into its query block or use qb_name or global object aliases (the latter two you have demonstrated).

Comment on How to copy partition stats? – We got easier way! by Dion Cho

Dion Cho — Thu, 16 Dec 2010 00:21:17 +0000

High value and low value are automatically adjusted by the procedure, but it’s also known that some versions have bugs failing at that.

You would need to check it yourself on your platform.

Comment on How to copy partition stats? – We got easier way! by Prasad

Prasad — Wed, 15 Dec 2010 15:30:57 +0000

Hi ,

Is it taking care of high value and low value by it self.?

Or do we have to set it mannualy.
Thanks & Regards,
Prasad

Comment on Interpreting Parallel MERGE Statement by Log Buffer #209, A Carnival of the Vanities for DBAs | The Pythian Blog

Log Buffer #209, A Carnival of the Vanities for DBAs | The Pythian Blog — Mon, 13 Dec 2010 04:33:05 +0000

[...] Andrey Goryunov’s top picks: Dion Cho, the Oracle Performance Storyteller, provides an explanation of parallel DML execution plan. [...]

Comment on Interesting combination of RAC and serial direct path read by Dion Cho

Dion Cho — Fri, 10 Dec 2010 02:03:29 +0000

Seems that _very_large_object_threshold parameter is valid only from 11gR2.

Oracle does direct read on the table whose size is bigger than around the that parameter. Seems that Oracle 11gR1 does not have such tweaks.

By the way, you can get the segment size from the dictionary views like dba_segments.

Comment on Interesting combination of RAC and serial direct path read by Tomas

Tomas — Mon, 06 Dec 2010 11:21:08 +0000

Thanks for reply,Dion

I use Oracle 11.1.0.7.0 and the only parameter containing very_large is _very_large_partitioned_table

(using the script http://www.tanelpoder.com/files/scripts/pd.sql)

My table space uses automatic segment space management with block size 8192B. How can I find the size of segment?

Comment on How to copy partition stats? – We got easier way! by raj

raj — Thu, 02 Dec 2010 03:13:55 +0000

Thanks much for checking.
regards
—Raj

Comment on How to copy partition stats? – We got easier way! by Dion Cho

Dion Cho — Thu, 02 Dec 2010 01:14:40 +0000

Hi Raj,

I searched docs and view defintions but, looks like we don’t have any column for that.

Comment on How to copy partition stats? – We got easier way! by raj

raj — Wed, 01 Dec 2010 08:44:30 +0000

Thanks for the post…It was useful..Googling took me here. Just wanted a small thing. Is there a column in any of the dictionary views or otherwise to know if the statistics on a partition is by mere copy or being gathered.

TIA.
—Raj

Comment on Making self deadlock on the library cache pin by Surachart Opun

Surachart Opun — Mon, 29 Nov 2010 03:37:21 +0000

Cool…
Some database, developers often recompile stored procedure.
We could not recompile stored procedure. After I checked I found that stored procedure hung in Library Cach…. I have to kill them.

I use this sql from Steve Adams (www.ixora.com.au)

SELECT
substr(DECODE(o.kglobtyp,
7, ‘PROCEDURE’, 8, ‘FUNCTION’, 9, ‘PACKAGE’, 12, ‘TRIGGER’, 13,
‘CLASS’),1,15) “TYPE”,
substr(o.kglnaown,1,30) “OWNER”,
substr(o.kglnaobj,1,30) “NAME”,
s.indx “SID”,
s.ksuseser “SERIAL”
FROM
sys.X$KGLOB o,
sys.X$KGLPN p,
sys.X$KSUSE s
WHERE
o.inst_id = USERENV(‘Instance’) AND
p.inst_id = USERENV(‘Instance’) AND
s.inst_id = USERENV(‘Instance’) AND
o.kglhdpmd = 2 AND
o.kglobtyp IN (7, 8, 9, 12, 13) AND
p.kglpnhdl = o.kglhdadr AND
s.addr = p.kglpnses and substr(o.kglnaobj,1,30)=’&NAME’
ORDER BY 1, 2, 3
/