Re: SQL EXPERTS ONLY
From: Mike Morgan <mike.morgan_at_teldta.com>
Date: 1996/07/30
Message-ID: <4tl9v6$jng_at_news2.tds.net>#1/1
Date: 1996/07/30
Message-ID: <4tl9v6$jng_at_news2.tds.net>#1/1
Simon Stow <sstow_at_uk.oracle.com> wrote:
>1. in user_tables there is a NUM_ROWS column so:
>
> select table_name, num_rows from user_tables;
>
>looks like it oughta work, but doesn't, at least not on my database -
>num_rows is null for all tables - maybe it requires something else to be
>switched on?
>
Simon,
The value of NUM_ROWS is assigned whenever you do an ANALYZE TABLE on the table in question. This is how the cost-based optimizer gets the statistics it needs to determine query paths.
HTH,
Mike Morgan
TDS Computing Services
#include <disclaimer.std>
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Received on Tue Jul 30 1996 - 00:00:00 CEST