I think there are various little (hah!) details that
change with versions, but unless your analyze
command was:
analyze table T estimate statistics sample 10 percent
for table
for indexes
for all indexed columns size 2
;
(I may have the sample clause in the wrong place).
then the two commands will be generating different
things. The default for analyze columns is 'size' 75,
which gives Oracle much better precision on range
scans with literal values than 'size 2' - which may be
a significant part of your problem.
Regards
Jonathan Lewis
http://www.jlcomp.demon.co.uk
The educated person is not the person
who can answer the questions, but the
person who can question the answers -- T. Schick Jr
One-day tutorials:
http://www.jlcomp.demon.co.uk/tutorial.html
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____UK___November
The Co-operative Oracle Users' FAQ
http://www.jlcomp.demon.co.uk/faq/ind_faq.html
----- Original Message -----
To: "Multiple recipients of list ORACLE-L" <[EMAIL PROTECTED]>
Sent: Wednesday, December 03, 2003 9:04 PM
Hello,
Oracle 8.1.7.4 on HP-UX 11i
A week ago, we replaced 'analyze table ... estimate statistics sample 10
percent' with dbms_stats.gather_schema_stats('x', estimate_percent=>10,
cascade=>true, degree=>4, method_opt=>''for all indexed columns size 2')
Performace is good against partitioned tables but not for non-partitioned
tables.
Saw a note in Metalink that its better to do the above with 'cascade=>false'
and then do a gather_index_stats separately.
In my tests, I see that 'analyze' makes the CBO use an index while
dbms_stats is making the CBO to use a FTS instead.
Have you faced any similar issues?
TIA
Prakash
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