Oracle Database - Session Statistics (V$SESSTAT)
Table of Contents
1 - About
2 - Articles Related
3 - Example
The second part of the autotrace output are a part of the session statistics.
Statistics ---------------------------------------------------------- 0 recursive calls 0 db block gets 24 consistent gets 0 physical reads 0 redo size 1598 bytes sent via SQL*Net to client 396 bytes received via SQL*Net from client 2 SQL*Net roundtrips to/from client 1 sorts (memory) 0 sorts (disk) 15 rows processed
4 - How to
4.1 - See
SELECT statname.display_name AS "Statistics Name", sesstat.value FROM v$sesstat sesstat, V$STATNAME statname WHERE sesstat.statistic# = statname.statistic# AND sesstat.sid = SYS_CONTEXT( 'USERENV', 'SID' ) ORDER BY statname.display_name;
5 - Statistics
5.1 - Recursive Call
recursive_calls : Number of SQL statements executed in order to execute your SQL statement
5.2 - Logical I/O
db block gets and consistent gets are the most important part of the output. They represent the Oracle Database - Buffer IO (Logical IO). The less we latch, the better.
- db block gets : Total number of block read from the buffer cache in current mode
- consistent gets : Number of times, a consistent read was requested for a block in the buffer cache. Consistent reads may require read asides to the undo (rollback) information, and these reads to the undo will be counted here as well.
5.3 - Physical read
5.4 - Redo
Oracle Database - Redo Size statistics : Total amount of redo generated in bytes during the execution of this statement
5.5 - SQL*Net Statistics
- bytes sent via SQL*Net to client : Total number of bytes sent to the client from the server
- bytes received via SQL*Net from client : Total number of bytes received from the client
- Oracle Database - SQL*Net roundtrips to from client : Total number of SQL*Net mesages sent to and received from the client. This includes round-trips for fetches from a multiple-row result set.
5.6 - Sorts
5.7 - Rows Processed
- Rows processed by modifications or returned from a SELECT statement.