Skip navigation.

Blogs

Progress status of an index rebuild or creation, or other long operations.

David Lozano Lucas's picture

When we launch a long operation, such as a RMAN backup or rebuild of a large index, we can come to despair of not having an estimate of the time it may take. We can even come to think that is doing nothing.

For the progress of a long operation we can query the view V$SESSION_LONGOPS, first obtaining the process ID from V$SESSION. In the case of DBA, we know exactly which user is rebuilding the index, so we can simplify it into a single query.

The following example shows the progress of the reconstruction of a partition of an index.

Constraints and performance: you want as many constraints as possible

Several times I have had to deal with people who do not want to define constraints. I have never understood why they don't, because my experience is that the more constraints you can define, the better Oracle will perform. If anyone knows where the idea that not defining constraints is a Good Thing comes from, I would be interested to know.

Following are two very simple examples of constraints allowing the optimizer to develop better plans.

First, foreign key constraints. These give the optimizer a lot of information about the data that may mean it can cut out whole tables from a query.

Partition Exchange by Example

One of the great features about partitioning, and most specifically range-based partitioning, is the ability to load data quickly and easily with minimal impact on the current users using:

alter table call exchange partition data_2007 with table call_temp;

Star Transformation

Star Transformation in Siebel Analytics (OBIEE)

(Subrata Dass)


Introduction

Star Transformation is a join method mostly used in Data Warehousing Environments to fine tune typical query performance. It is of utmost importance in DB environments where reporting tools like Siebel Analytics (OBIEE) is in use. It can also be used for other tools such as Business Objects. The conventional join mechanisms that the star transformation seeks to supersede are Hash join, nested-loops and sort merge join.

This paper shows how to take full advantage of this RDBMS feature.

How to make Dynamic List Item in Oracle Forms Builder?

In this article I will tell you how you can make a dynamic List of values in oracle forms builder, most developer use many techniques to make List of values.

Best practice - Implementation of OA Framework Technology

This post is to discuss about the Best Practices that was followed in implementing a new Self Service Applications using OA Framework.

A College needed a web based enrollment system for its students to enroll online without needing to fill up a paper. This was designed for a new i-module for Student Enrolment was developed in OA Framework, using jDeveloper,Rapid Application Development Environment. The benefits of the RAD environment and OA Framework Technology was well utilized to meet the deadlines.

The main challenges faced by the project were , I identification of a roadmap to transform existing system and there was no proper oracle documentation on how to develop a transaction page in OA Framework.

Playing with Oracle Lobs

dwaipayan19861's picture

LOBs deal with unstructured data, the ones which are the most difficult to store and retrieve in a relational database.

In this article, I am going to discuss extensively and manipulate the ORACLE

* LOBs that are stored in the database itself like BLOB,CLOB,NCLOB ,and

* LOBs like BFILE which are Stored outside the database as Operating System files.

First let us create a directory :

create or replace directory my_dir as 'D:\pics';
Directory created.

BFILE:
BFILEs act as a pointer and store the location of the external OS files in database tables.

1.

Oracle RMAN Reporting

For any company the most important asset is data and the most challenging job is to recovery the database with less downtime with out any data loss, in the event of database failure. In many situations users end up with incomplete recovery of the database with out knowing which data files backed and which data files need to backup. You should ensure that your database is backed up efficiently and should restore successfully when needed. The RMAN reporting provides effective and easy way to determine database backup for a successful recovery.

DBMS_FGA - Oracle Fine Grained Auditing

dwaipayan1986's picture

Suppose your boss calls you one day and tells you that there has been some unexpected changes in the employee database.Employee's designation, their salary are being manipulated illegally.Such things have been continuing from a past few days and he asks if you could help getting hold of the culprit.
Don't worry Oracle's DBMS_FGA package will save your day and earn you a raise in your job.

The Oracle DBMS_FGA package provides fine grained auditing on objects.

To have an overview of the summary of dbms_fga subprograms visit :

»

ORA-1555 and SQL Tuning

Often DBAs may look to tuning the UNDO* parameters as a solution towards the infamous "ORA-1555 snapshot too old" error. In most cases, before looking to tune UNDO* parameters, the best solution is to tune the query that's running into the ORA-1555 error so the query will not error out with ORA-1555 to begin with!

Hope this helps a fellow DBA or two trying to resolve the ORA-1555(s) !