I have
done some test before and found out that analyze is faster than dbms_stats for
smaller tables only (less than 10M) - and the difference was not that big (for
example very small tables dbms_stats would do a compute instead of
estimate). For large tables they are pretty much the same. And this
is comparing dbms_stats working in serial mode. You can do stuff in parallel
which could change the picture in dbms_stats
favor.
dbms_stats is more accurate (since its introduction incorrect statistics
gathering was discovered for ANALYZE), it supports better granularity control
(partitions, subpartitions). Using dbms_stats you can also export and
import statistics: save the old statistics before the run and reuse the old
statistics in case you don't like the new ones.
There
are a number of other advantages: treating stale tables, automatic estimate
sample size, collecting histogram info only for skewed columns (at least the
ones that oracle thinks are skewed). Using dbms_stats you can also collect
system stats.
And
analyze is not depreciated in 9i.
AFAIK
the only things dbms_stats does not do are: finding chained/migrated rows,
computing cluster statistics, and validating the structure.
Djordje
-----Original Message-----
From: Jayaram Keshava Murthy (Cognizant) [mailto:[EMAIL PROTECTED]
Sent: Monday, June 02, 2003 10:50 AM
To: Multiple recipients of list ORACLE-L
Subject: Need helpHi all,Can anyone tell me which of the following performs better in collecting statistics of a table:Analyze command orDbms_stats.gather_table_statsI tried my queries with both the options -- but always Analyze is out-performing the dbms_stats.But i read in a document that Dbms_stats performs better !!Besides I also read that Analyze command will be deprecated from Oracle 9i.So can anyone tell me why dbms_stats is performing poor...Are there any paramters that need to be set to increase the performace of dbms_stats ?Thanks in advance.RegardsKesh
