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Metalink Performance Library Index
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Locally Managed Tablespace and Dictionary managed tablespace (LMT-DMT)
BENEFITS of Locally Managed Tablespaces ————————————— Locally managed tablespaces track all extent information in the tablespace itself, using bitmaps, resulting in the following benefits: * Improved concurrency and speed of space operations, because space allocations and deallocations predominantly modify locally managed resources (bitmaps stored in header files) rather than requiring centrally managed resources such as…
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True Session Wait Activity in Oracle 10g Verygood
True Session Wait Activity in Oracle 10g ======================================== Catching a session waiting on a resource used to be hit or miss. Let’s take a look at how Oracle has helped give us a better mousetrap for seeing the waits experienced by sessions. It used to be that a DBA would sit in front of the…
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Absolute file number and relative file number
Interpreting Wait Event “file#” and “block#” parameters ======================================================= This reference note describes how to interpret file# and block# parameters from wait events (eg: obtained from or from the WAIT trace lines in trace files). The text uses: &AFN to represent the absolute file number (file#) &BLOCKNO to represent the block number (block#) IMPORTANT: The details…
Important Script Method for tuning
wait.sql enqueue_type.sql lck.sql
lck.sql
select c.sid, c.serial#, c.username, a.object_id, b.object_name, c.program, c.status, d.name, c.osuser, e.sql_text, DBMS_ROWID.ROWID_CREATE(1, c.ROW_WAIT_OBJ#, c.ROW_WAIT_FILE#, c.ROW_WAIT_BLOCK#, c.ROW_WAIT_ROW# ) locked_rowid from v$Locked_object a, All_objects b, v$session c, audit_actions d, v$sqlarea e where a.object_id=b.object_id and a.session_id =c.sid(+) and c.command=d.action and c.row_wait_obj# != -1 and c.sql_id=e.sql_id;
The most important Tuning Notes
Note:61552.1 Database Is Slow. (*) Any recent upgrade/degrade activities??? (2)Check Alert.log and trace files for any cause. (2) Check # of sessions, # of processes. (3) Check event init.ora parameter to see whether any event is set or not. (4) check # of log switching. (5) check archive log destinations space problem or ARCH may…
Oracle 10g Wait Model
*** This article is being delivered in Draft form and may contain errors. Please use the MetaLink “Feedback” button to advise Oracle of any issues related to this article. *** PURPOSE ——- This note includes new columns of V$SESSION and how to effectively use V$SESSION during contention in Oracle 10G. SCOPE & APPLICATION —————————– 1….
Debugging Shell FIles
sh -x ./myshellfile.sh
Rename Tablespace
Alter tablespace OLD_ts_name rename to NEW_TS_NAME;