Some Useful Database Commands Part - 1

SOme  Useful Oracle Database Commands Part - 1

Flushing the shared pool

To flush the shared pool use:
    ALTER SYSTEM FLUSH SHARED_POOL;

Flushing the buffer cacheIn Oracle 10.1 and above, the following supported command can be used to flush the buffer cache:
    ALTER SYSTEM FLUSH BUFFER_CACHE;

In Oracle 9.0.1 and above the following unsupported command can also be used to flush the buffer cache:
    ALTER SESSION SET EVENTS 'immediate trace name flush_cache';

After this command has been executed, the STATE column for all rows in X$BH will be zero unless the block is currently pinned
In Oracle 9.2.0.1 (Windows 2000) the equivalent ORADEBUG command fails with ORA-3113
Forcing a checkpoint

To force a checkpoint use
    ALTER SYSTEM CHECKPOINT;

Forcing a logfile switch
To force a logfile switch use

    ALTER SYSTEM SWITCH LOGFILE;