AUTOTRACE
AUTOTRACE, introduced in Oracle8i, enables automatic reporting on statements issued in SQL*Plus. To use AUTOTRACE, a PLAN_TABLE must exist (for the storage of EXPLAIN PLAN information) and the user must have been granted the PLUSTRACE role. The PLUSTRACE role is created by running the PLUSTRACE.SQL script as DBA; it may then be granted to other users.
You can control AUTOTRACE operations by issuing the following statement:
SET AUTOTRACE ON | OFF | TRACEONLY optionwhere option can be EXPLAIN or STATISTICS. Without an option, AUTOTRACE returns information on the optimization (EXPLAIN) and the statistics used by the statement. If you specify TRACEONLY, the statement returns the optimizer plan and the statistics but does not return any result.
The statistics that are created by AUTOTRACE are:
| Recursive calls |
| DB block - gets number of times a CURRENT block was requested |
| Consistent - gets number of times a consistent read was requested for a block |
| Physical reads - number of datablocks read from disk |
| Redo size - amount of redo generated, listed in bytes |
| Bytes sent via Oracle Net Services to client |
| Bytes sent via Oracle Net Services from client |
| SQL*Net round-trips to and from clients |
| Sorts in memory |
| Sorts in disk |
| Rows processed |