Re: dbms_stats and incorrect statistics

I bet DATEFIRED has 5842 NULLs - or had at the time you gathered the stats.

At 01:12 AM 5/31/2007, Ronnie Doggart wrote:
Hi,

Oracle 9.2.0.8 on Oracle Enterprise Linux

We looking at reducing the amount of time taken to gather statistics on our production database. Initially we where using dbms_stats.gather_schema_stats with compute and cascade=>true. We want to use an estimate on the tables and compute on the indexes so we split the analysis up. However during testing we noticed that some tables had stats that where inconsistent. For instance using dbms_stats.gather_table_stats with compute the number of rows reported as sampled varied on a column per column basis in the same table e.g

TABLE_NAME COLUMN_NAME DATA_TYPE NUM_DISTINCT SAMPLE_SIZE LGNCC_ESCRULE ESCRULESTATUS NUMBER 4 14563 LGNCC_ESCRULE DATEFIRED DATE 4896 8721

Does a compute not read all the rows in a table for each column, the table above has 14563 rows.

Regards

Wolfgang Breitling
Centrex Consulting Corporation
www.centrexcc.com
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