Oracle Masters

Architecture andBackup/Recovery

Thursday, 16 Jul 2009 3:06 AM

Steps for restore from tape

By tdomf_2a078

1 Reply »

I am using the oracle9 on solaris 8
we are taking our backup on veritas Netbackup

Pls guide me that what are the steps i need to follow
for restoring my data from tape to server

Pls reply ASAP

Thanks

Popularity: 3% [?]

Architecture andPerformance Tuning andPerformance Tuning FAQs

Monday, 13 Jul 2009 1:03 AM

Diff:Latches and Locks

By Ruxina

4 Replies »

Dear Ramesh,

Please help to understand the difference between latches and locks.

Thanks,
Ruxina

Popularity: 19% [?]

Performance Tuning andUncategorized

Saturday, 11 Jul 2009 9:38 PM

Enqueues – Demonstration

By Ramesh Menon

No Replies »

This entry is part 2 of 2 in the series Enqueues

In this section, we will go through a demo of generating and detecting locks with scripts

Read the rest of this entry »

Popularity: 53% [?]

Performance Tuning FAQs

Saturday, 11 Jul 2009 8:55 AM

Enqueues – Introduction

By Ramesh Menon

1 Reply »

This entry is part 1 of 2 in the series Enqueues

Enqueues/Locks in Oracle

One aspect of Oracle DBA’s job, is to analyze performance issues related to enqueue waits and tune or suggest remedies to the application development team. To do this, it is important to understand what are locks and how you can identify some of the issues related to locking and waits due to locking (enqueue waits).

Oracle documentation defines locks as

“Locks are mechanisms that prevent destructive interaction between transactions accessing the same resource—either user objects such as tables and rows or system objects not visible to users, such as shared data structures in memory and data dictionary rows.”

What it means is that locks are objects that protect resources from being acccessed concurrently, in incompatible modes. For example, if you are updating a row from one session, Oracle needs to ensure that other sessions can modify this row, only after your session either commits or rollbacks the transaction.”

Thus, locks (or enqueues) are used to

Prevent two sessions from writing the same row of a table at the same time
Facilitate enforcement of parent/child locking for referential integrity
Prevent two sessions from updating the definition of a table (drop/add column, etc) at the same time

Read the rest of this entry »

Popularity: 37% [?]

Architecture andPerformance Tuning

Saturday, 20 Jun 2009 1:15 AM

Histogram

By sandeepchavan25

1 Reply »

what is histogram?wht are the types of histogram in details

Popularity: 93% [?]

Architecture

Friday, 5 Jun 2009 9:48 PM

Global Temporary Table

By niket

5 Replies »

1) Global temporary table use temp segments when inserted but when deleted we still get information about the table in dba_tables view.
Where does it store information?

2) Does performace increases while using global temporary table while generating report.

3) As it uses temporary tablespace there will be less space available for other sort transaction – right
So How much data is advisable to store in global temporary table ?

Kindly guide us.

Regards
Niket

Popularity: 93% [?]

Architecture andDBA Posts

Thursday, 21 May 2009 10:05 PM