BC remote Oracle DBA - Call (800) 766-1884  
Oracle Consulting Oracle Training Development

Remote DBA

Remote DBA Plans  

Remote DBA Service

Remote DBA RAC

   
Remote DBA Oracle Home
Remote DBA Oracle Training
Remote DBA SQL Tuning Consulting
Remote DBA Oracle Tuning Consulting
Remote DBA Data Warehouse Consulting
Remote DBA Oracle Project Management
Remote DBA Oracle Security Assessment
Remote DBA Unix Consulting
Burleson Books
Burleson Articles
Burleson Web Courses
Burleson Qualifications
Oracle Links
Remote DBA Oracle Monitoring
Remote DBA Support Benefits
Remote DBA Plans & Prices
Our Automation Strategy
What We Monitor
Oracle Apps Support
Print Our Brochure
Contact Us (e-mail)
Oracle Job Opportunities
Oracle Consulting Prices





   

 

 

 

Remote DBA services

Remote DBA Support

Remote DBA RAC

Remote DBA Reasons

Remote Oracle Tuning

Remote DBA Links

Oracle DBA Support

Oracle DBA Forum

Oracle Disaster

Oracle Training

Oracle Tuning

Oracle Training

 Remote DBA SQL Server

Remote MSSQL Consulting

Oracle DBA Hosting

Oracle License Negotiation

 

 


 

 

 

 

 

 

 

SQL Internal Processing

Oracle Tips by Burleson Consulting

This chapter is concerned with providing a detailed understanding of how SQL is processed within the Oracle database instance. We will be exploring the Oracle library cache, and you will see how you can write queries to see exactly what is happening to your SQL statements. We will also explore techniques for investigating SQL sort activity and see how you can quickly find SQL statements that are invoking disk sorts. Best of all, I will show you how to get the execution plan for all SQL statements in the library cache and create reports that show you exactly what your SQL is doing. This chapter will include the following sections:

  • Oracle shared SQL and private SQL areas

  • SGA statistics for SQL

  • Monitoring and tuning Oracle sorting

  • Identifying high-impact SQL in the library cache

  • Reporting on SQL in the library cache

Let’s begin with an in-depth overview of the SQL areas.

Shared and Private SQL Areas

Within the library cache, Oracle stores the source for your SQL statement as well as the execution plan for the SQL. Within an individual SQL statement, Oracle partitions the SQL into several areas, a shared area and a private area (see Figure 5-1). In order to make all SQL statements reusable, Oracle segments the parts of the SQL statement that are generic into the shared area, specifically the original parse tree for the SQL and the execution plan. The private SQL area, which includes SQL information that is user-specific, is divided into a persistent areas and a run-time area. The persistent area remains in memory unless the corresponding cursor has been closed. Hence, you should always close all open cursors that will not be used again for better memory utilization within the private SQL area. The run-time area is freed after the statement is executed.

Figure 1: The SQL shared and private areas

The private area includes binding data, run-time buffers, cursors, host variables, and other control structures that are specific to the user. The separation of the SQL areas allows Oracle SQL to remain fully reentrant and reusable while allowing simultaneous execution of any SQL statement.

Next, let’s look at some system-wide SGA statistics that can give us insight into our SQL behavior.



This is an excerpt from "Oracle High-Performance SQL Tuning" by Donald K. Burleson, published by Oracle Press.


Expert Remote DBA

BC is America's oldest and largest Remote DBA Oracle support provider.  Get real Remote DBA experts, call
BC Remote DBA today.

 

 

Remote DBA Service
 

Oracle Tuning Book

 

Advance SQL Tuning Book 

BC Oracle support

Oracle books by Rampant

Oracle monitoring software

 

 

 

 

 

 

BC Remote Oracle Support

Remote DBA

Remote DBA Services

Copyright © 1996 -  2013 by Burleson. All rights reserved.

Oracle® is the registered trademark of Oracle Corporation.



Hit Counter