RE: Need some 10053 Guidance to help me solve a puzzler

  • From: <Christopher.Taylor2@xxxxxxxxxxxx>
  • To: <jonathan@xxxxxxxxxxxxxxxxxx>, <oracle-l@xxxxxxxxxxxxx>
  • Date: Thu, 11 Oct 2012 13:15:29 -0500

1.)
Quote:
--  Okay, bit of a coincidence on the costing, then, but
--  what's the block size
--  what do the system stats look like

db_block_size=8192

system stats:
SYSSTATS_MAIN   CPUSPEEDNW      1878.73888439774
SYSSTATS_MAIN   IOSEEKTIM       10
SYSSTATS_MAIN   IOTFRSPEED      4096
SYSSTATS_MAIN   SREADTIM        1.562
SYSSTATS_MAIN   MREADTIM        26.342
SYSSTATS_MAIN   CPUSPEED        3003
SYSSTATS_MAIN   MBRC            871
SYSSTATS_MAIN   MAXTHR  287382528
SYSSTATS_MAIN   SLAVETHR        29696

(see anything here that bears on this issue?)

2.)
Quote:
--should have been more like "the bit of the table needed by the indexed 
access path is nearly completely cached"

Okay that would make sense.

3.) 
Quote:
-- Oracle thinks that the data you want is all over the place and will 
require a very large number of random reads
-- it's possible that the data you want is actually all packed into a 
fairly small part of the table

That also makes sense.

4.) 
Quote:
-- How big is the table really, how big is the cache. My comment was that 
the table was largely UNcached.

Table Size:
5958.75MB (~6GB)        23835 Extents

Cache:
Buffer Cache: 24,832 MB (~24GB)

5.) 
Quote
-- There's a very good book about this called "Cost Based Oracle - 
Fundamentals" (I wrote it, so I am biased, though).

I have your book :-p  (Reading about something is a lot different than getting 
to get your hands onto it and really understanding it!)

Chris




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