Oracle Consulting Oracle Training Oracle Support Development
Home
Catalog
Oracle Books
SQL Server Books
IT Books
Job Interview Books
eBooks
Rampant Horse Books
911 Series
Pedagogue Books

Oracle Software
image
Write for Rampant
Publish with Rampant
Rampant News
Rampant Authors
Rampant Staff
 Phone
 800-766-1884
Oracle News
Oracle Forum
Oracle Tips
Articles by our Authors
Press Releases
SQL Server Books
image
image

Oracle 11g Books

Oracle tuning

Oracle training

Oracle support

Remote Oracle

STATSPACK Viewer

Privacy Policy

 

   
  Oracle Tips by Burleson

Disk I/O and the Shared Pool

The shared SQL area contains the Pcode versions of all of the current SQL commands that haven’t been aged out of the shared pool. Numerous statistics are available via the v$sqlarea DPT. The text of SQL statements in the shared pool can be retrieved (at least the first tens of bytes) from the v$sqltext and v$sqlarea DPTs. Let’s look at a report that displays the SQL statements in the SQL area with the greatest number of disk reads (these will probably be the ones you will want to review and tune). Look at the report in Source 13.10. Output from this report is shown in Listing 13.11.

SOURCE 13.10 SQL versus disk reads report.

REM Name: sqldrd.sql
REM Function: return the sql statements from the shared area with
REM Function: highest disk reads
REM History: Presented in paper 35 at IOUG-A 1997, converted for
REM use 6/24/97 MRA
REM
DEFINE access_level = 1000 (NUMBER)
COLUMN parsing_user_id FORMAT 9999999 HEADING ‘User Id’
COLUMN executions FORMAT 9999 HEADING ‘Exec’
COLUMN sorts FORMAT 99999 HEADING ‘Sorts’
COLUMN command_type FORMAT 99999 HEADING ‘CmdT’
COLUMN disk_reads FORMAT 999,999,999 HEADING ‘Block Reads’
COLUMN sql_text FORMAT a40 HEADING ‘Statement’ WORD_WRAPPED
SET LINES 130 VERIFY OFF FEEDBACK OFF
START title132 'SQL Statements With High Reads'
SPOOL rep_out/&db/sqldrd.lis
SELECT
parsing_user_id, executions,
sorts,command_type,
disk_reads,sql_text
FROM
v$sqlarea
WHERE


By tuning those statements that show large numbers of disk reads, the overall performance of the application is increased.


This is an excerpt by Mike Ault’s book “Oracle9i Administration & Management” .  If you want more current Oracle tips by Mike Ault, check out his new book “Mike Ault’s Oracle Internals Monitoring & Tuning Scripts” or Ault’s Oracle Scripts Download.

Linux Oracle commands syntax poster

ION Oracle tuning software

Oracle data dictionary reference poster



Oracle Forum

BC Oracle consulting support training

BC remote Oracle DBA   

 

   

 Copyright © 1996 -2016 by Burleson. All rights reserved.


Oracle® is the registered trademark of Oracle Corporation. SQL Server® is the registered trademark of Microsoft Corporation. 
Many of the designations used by computer vendors to distinguish their products are claimed as Trademarks
 

Hit Counter