Skip to main content

CREATING EXPLAIN PLAN FOR ORACLE SQL


CREATING EXPLAIN PLAN FOR ORACLE SQL


The EXPLAIN PLAN statement displays execution plans chosen
by the Oracle optimizer for SELECT, UPDATE, INSERT, and
DELETE statements.

Run This Script  To create Plan Table

$ORACLE_HOME/rdbms/admin/utlxplan.sql

Execute the SQL command like the following.

SQL> explain plan for select * from ultimus.cor_trans_gl_hist where year=2009 order by

branch_id;

Explained

SQL> select * from table(dbms_xplan.display);

PLAN_TABLE_OUTPUT
--------------------------------------------------------------------------------
Plan hash value: 1485638787
--------------------------------------------------------------------------------
| Id  | Operation          | Name              | Rows  | Bytes |TempSpc| Cost (%
--------------------------------------------------------------------------------
|   0 | SELECT STATEMENT   |                   |  2429K|   651M|       |   365K
|   1 |  SORT ORDER BY     |                   |  2429K|   651M|  1807M|   365K
|*  2 |   TABLE ACCESS FULL| COR_TRANS_GL_HIST |  2429K|   651M|       |   218K
--------------------------------------------------------------------------------
Predicate Information (identified by operation id):
---------------------------------------------------
   2 - filter(TO_NUMBER("YEAR")=2009)

14 rows selected

----------------------------------------------------------------------------------------------
Labels:

Comments

Post a Comment

Popular posts from this blog

ORACLE FLASH RECOVERY AREA USAGE QUERY

FINDING ORACLE FLASH RECOVERY AREA USAGE SELECT NAME,        (SPACE_LIMIT / 1024 / 1024 / 1024) SPACE_LIMIT_GB,          ((SPACE_LIMIT - SPACE_USED + SPACE_RECLAIMABLE) / 1024 / 1024 / 1024) AS SPACE_AVAILABLE_GB,        ROUND((SPACE_USED - SPACE_RECLAIMABLE) / SPACE_LIMIT * 100, 1) AS PERCENT_FULL   FROM V$RECOVERY_FILE_DEST;
Post a Comment
Read more

Shared Pool Tuning: Cursor Tuning (Tuning Open_Cursors, Session_Cached_Cursors, Cursor_Space_For_Time)

Shared Pool Tuning: Cursor Tuning The three most important parameter for shared pool tuning are OPEN_CURSORS , SESSION_CACHED_CURSORS and CURSOR_SPACE_FOR_TIME. But most of the time we see that these two parameters SESSION_CACHED_CURSORS and CURSOR_SPACE_FOR_TIME are ignored or unused . OPEN CURSORS Open cursors take up space in the shared pool, in the library cache. OPEN_CURSORS sets the maximum number of cursors each session can have open, per session. For example, if OPEN_CURSORS is set to 1000, then each session can have up to 1000 cursors open at one time. V$open_cursor shows cached cursors, not currently open cursors, by session. If you’re wondering how many cursors a session has open, don’t look in v$open_cursor. It shows the cursors in the session cursor cache for each session, not cursors that are actually open.  To monitor open cursors, query v$sesstat where name= ’opened cursors current’ . This will give the number of currently opened cursors, by session:
Post a Comment
Read more

How to delete/remove Management Agent from Oracle Enterprise Manager 12C

  1. Before you deinstall a Management Agent, do the following:     a. Stop the Agent using command from Management Agent home:                 cd /u01/oemcc_latest/core/12.1.0.2.0/bin/                 $ emctl stop agent     b. Wait for the Management Agent to go to the unreachable state in the Cloud Control console.     c. It is mandatory to delete the Management Agent and their monitored targets using any of the following methods: Remove the Agent target manually from the console: 1. Login to 12C Cloud Control 2. Navigate to Setup => Manage Cloud Control => Agents 3. Go to the Home page of the Agent that you want to remove 4. Expand the drop-down menu near the " Agent " 5. Expand the " Target Setup " option 6. Select " Remove Target "            In Cloud Control Release 12.1.0.2, the following dialog box will be displayed if the Agent is still monitoring targets. Click Continue. You can then remove all targets (usin
Post a Comment
Read more