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16 de Agosto del 2005

Cuando el atributo de la tabla user_tables monitoring tiene el valor YES para que sirve esto???


16 de Agosto del 2005
Under Oracle7 and 8.0, in order to get up-to-date statistics so

that the Cost-Based Optimizer can generate accurate execution plans,

the DBA must gather regular statistics (DBMS_STATS.GATHER_xx_STATS) whenever

significant new amounts of data are created, as there is no way of knowing

which tables have been updated and therefore which tables need to gather agin statistics.

This is expensive.

Under Oracle8i, the DBA can set a table to be automatically detected

when any modification occurs. When enabled, whenever any modification

(insert, update, delete, and direct load) occurs on the table or on

one of its partitions, the server maintains information in the SGA

about how many rows are affected. Therefore, the DBA is now able to

re-analyze tables only when changes have occurred on a table.