Re: How many buckets

DA Morgan wrote:
> Js wrote:
> > Hello Experts,
> >
> > I need your comments on below topic.
> >
> > Oracle generating 2 buckets for each column if I am executing this
> > command.
> >
> > SQL> analyze table t compute statistics;
> >
> > Table analyzed.
> >
> > SQL> select count(*),column_name from user_Tab_histograms where
> > table_name = 'T' group by column_name;
> >
> > COUNT(*) COLUMN_NAME
> > ---------- --------------------------------------------------
> > 2 CREATED
> > 2 DATA_OBJECT_ID
> > 2 GENERATED
> > 2 LAST_DDL_TIME
> > 2 OBJECT_ID
> > 2 OBJECT_NAME
> > 2 OBJECT_TYPE
> > 2 OWNER
> > 2 SECONDARY
> > 2 STATUS
> > 2 SUBOBJECT_NAME
> > 2 TEMPORARY
> > 2 TIMESTAMP
> >
> > 13 rows selected.
> >
> > And If use this command ...
> >
> > SQL> analyze table t compute statistics for table for all columns;
> >
> > Table analyzed.
> >
> > SQL> select count(*),column_name from user_Tab_histograms where
> > table_name = 'T' group by column_name;
> >
> > COUNT(*) COLUMN_NAME
> > ---------- --------------------------------------------------
> > 76 CREATED
> > 75 DATA_OBJECT_ID
> > 2 GENERATED
> > 76 LAST_DDL_TIME
> > 76 OBJECT_ID
> > 76 OBJECT_NAME
> > 24 OBJECT_TYPE
> > 11 OWNER
> > 1 SECONDARY
> > 2 STATUS
> > 2 SUBOBJECT_NAME
> > 2 TEMPORARY
> > 76 TIMESTAMP
> >
> >
> > I am confused .. No of buckets is dependent upon what ?
> >
> > Regards.
>
> http://download-west.oracle.com/docs/cd/B19306_01/server.102/b14200/statements_4005.htm#SQLRF01105
>
> also: http://tahiti.oracle.com
> and search for "Bucket" and "ANALYZE" together
> --
> Daniel A. Morgan
> http://www.psoug.org
> damorgan_at_x.washington.edu
> (replace x with u to respond)

Nice tip. Do us all a favor and don't suggest RTFM unless the OP really deserves it. In this case, I think not. Received on Wed Dec 21 2005 - 13:11:08 CST