Solved

A Question about Oracle SQL Statment processing

Posted on 2012-04-11
2
336 Views
Last Modified: 2012-09-07
Dear Experts,

What are the genarel reasons for SQL Statments processing slowness of Oracle Database?
Additionally tell me,

(1).What is the effect of Memory for SQL Statement processing?
(2).Is there any relationship with undo tablespace and UPDATE Statements?

Thank You in advance.
Pradeep.
0
Comment
Question by:uompradeep
2 Comments
 
LVL 12

Accepted Solution

by:
praveencpk earned 500 total points
ID: 37836412
some of the genral reasons for poor perforamce of SQL statements is

Bad Design
Poor coding
Old Statistics
less memory

check this doc for more detail info

http://www.dba-oracle.com/t_top_reasons_poor_performance.htm

(2).Is there any relationship with undo tablespace and UPDATE Statements?

when ever you update a row in a table, then the old value of the row is stored in your undo tablespace  for your rollback purpose.

Undo also provides read consistency for users who are querying rows involved in a DML transaction by another user or session. When one user starts to make changes to a table after another user has already begun a query against the table, the user issuing the query will not see the changes to the table until after the query has completed and the user issues a new query against the table.
0
 
LVL 16

Expert Comment

by:Wasim Akram Shaik
ID: 37836499
Regarding your first point

What is the effect of Memory for SQL Statement processing?

Detailed explanation can be found in burleson site..

http://www.dba-oracle.com/sql/t_sql_execution_steps_parsing_fetching.htm

2nd point, i agree with expert praveen..

further to this, refer to the blogs for detailed information

http://ora10g.com/6_1_undo.html
0

Featured Post

Networking for the Cloud Era

Join Microsoft and Riverbed for a discussion and demonstration of enhancements to SteelConnect:
-One-click orchestration and cloud connectivity in Azure environments
-Tight integration of SD-WAN and WAN optimization capabilities
-Scalability and resiliency equal to a data center

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

I remember the day when someone asked me to create a user for an application developement. The user should be able to create views and materialized views and, so, I used the following syntax: (CODE) This way, I guessed, I would ensure that use…
Background In several of the companies I have worked for, I noticed that corporate reporting is off loaded from the production database and done mainly on a clone database which needs to be kept up to date daily by various means, be it a logical…
This video shows information on the Oracle Data Dictionary, starting with the Oracle documentation, explaining the different types of Data Dictionary views available by group and permissions as well as giving examples on how to retrieve data from th…
This video shows how to Export data from an Oracle database using the Original Export Utility.  The corresponding Import utility, which works the same way is referenced, but not demonstrated.

808 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question