Re: how to deal with this situation? truncate table + statistics

Hi , before you should backup your statistics data for this table, and after truncation, just import it.
 Please check the reference book of dbms_stats.  On 9/13/05, Enrique Fernandez-Pampillon <oracle.pampillon_at_gmail.com> wrote:
>
> Hello,
>
> Although the table is empty with:
>
> dbms_stats.set_table_stats( user, 'TABLE', numrows => 50000,
> numblks => 10000 );
> dbms_stats.set_column_stats( user, 'TABLE', 'COLUMN', distcnt => 15000 );
>
> you can "simulate" the number of rows and blocks you wish.
>
> Bye
>
> --
> Enrique
>
> On 9/13/05, The Human Fly <sjaffarhussain_at_gmail.com> wrote:
> > Hello List,
> >
> > Well, I have a little bit tricky or I can say confused situation. We
> > have database for shares tradining. Beginning of every day, a couple
> > of tables will be truncted and we analyze the schema.
> > The situation is, when we truncate and analzye those tables,
> > statitiscs are updated as rum_rows=0, and blocks =0. The entire day,
> > about 100,000 records comes in each of those truncated tables. But,
> > for the optimizer, the data dictionary statistics provides nothing,
> > when there are records coming every second, we dont re-analyze again,
> > i.e. old statistics available to the optimizer.
> > How can we deal with this situation? Is it better to collect the
> > statistics before table get truncated, so that statistics available
> > for those tables to help otpimizer? If so, lets say, if our num_rows
> > says 100,000 and truncated the table, when records start coming in a
> > table, optimizer assumed that this table has 100,000 records, may be
> > the empty table starts filling from 10 records and keep growing.?
> > What is the best way to deal this?
> >
> > --
> > Best Regards,
> > Syed Jaffar Hussain
> > OCP 8i & 9i DBA,
> > Banque Saudi Fransi,
> > Saudi Arabia
> >
> ----------------------------------------------------------------------------------------
> > "It is your atittude, not your aptitude that determins your altitude."
> > --
> > http://www.freelists.org/webpage/oracle-l
> >
>
>
> --
> ------------------------------------------------
> Enrique
> --
> http://www.freelists.org/webpage/oracle-l
>

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