Performance Enhancements Using Temporary Tables

A temporary table has a definition or structure like that of a regular table, but the data it contains exists for only the duration of a transaction or session. Oracle8i allows you to create temporary tables, which can be bound to a session or to a transaction.

You can use temporary tables to improve performance when running an otherwise complex and expensive query. To do this, you can cache the values from a more complex query in temporary tables, then run SQL statements, such as joins, against those temporary tables. Thus, the performance of your queries can improve drastically.

You can create indexes on temporary tables. Another benefit of using temporary tables is that they do not automatically allocate a segment when they are created. Instead, segments are allocated when the first INSERT (or CREATE TABLE AS SELECT) is performed. This means that if a SELECT, UPDATE, or DELETE is performed before the first INSERT, the table appears to be empty. The data in these tables get automatically deleted at the end of the transaction, or a session depending upon the type of the temporary table declared. The syntax for creating session-specific temporary tables is:

 CREATE GLOBAL TEMPORARY TABLE . . .		[ON COMMIT PRESERVE ROWS]

The syntax for creating transaction-specific temporary tables is:

 CREATE GLOBAL TEMPORARY TABLE . . .		[ON COMMIT DELETE ROWS]
Share the Post:
Share on facebook
Share on twitter
Share on linkedin

Overview

The Latest

iOS app development

The Future of iOS App Development: Trends to Watch

When it launched in 2008, the Apple App Store only had 500 apps available. By the first quarter of 2022, the store had about 2.18 million iOS-exclusive apps. Average monthly app releases for the platform reached 34,000 in the first half of 2022, indicating rapid growth in iOS app development.

microsoft careers

Top Careers at Microsoft

Microsoft has gained its position as one of the top companies in the world, and Microsoft careers are flourishing. This multinational company is efficiently developing popular software and computers with other consumer electronics. It is a dream come true for so many people to acquire a high paid, high-prestige job

your company's audio

4 Areas of Your Company Where Your Audio Really Matters

Your company probably relies on audio more than you realize. Whether you’re creating a spoken text message to a colleague or giving a speech, you want your audio to shine. Otherwise, you could cause avoidable friction points and potentially hurt your brand reputation. For example, let’s say you create a