A Question about Oracle SQL Statment processing

Posted on 2012-04-11
Medium Priority
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.
Question by:Pradeep Siriwardana
LVL 12

Accepted Solution

Praveen Kumar Chandrashekatr earned 1500 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


(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.
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..


2nd point, i agree with expert praveen..

further to this, refer to the blogs for detailed information


Featured Post

7 new features that'll make your work life better

It’s our mission to create a product that solves the huge challenges you face at work every day. In case you missed it, here are 7 delightful things we've added recently to monday to make it even more awesome.

Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

Join & Write a Comment

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…
This post first appeared at Oracleinaction  (http://oracleinaction.com/undo-and-redo-in-oracle/)by Anju Garg (Myself). I  will demonstrate that undo for DML’s is stored both in undo tablespace and online redo logs. Then, we will analyze the reaso…
This video shows, step by step, how to configure Oracle Heterogeneous Services via the Generic Gateway Agent in order to make a connection from an Oracle session and access a remote SQL Server database table.
Via a live example, show how to take different types of Oracle backups using RMAN.
Suggested Courses

597 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