Overview of System Tables, Temporary Tables, and Views

From InterBase
Jump to: navigation, search

Go Up to System Tables, Temporary Tables, and Views


The InterBase system tables contain and track metadata. InterBase automatically creates system tables when a database is created. Each time a user creates or modifies metadata through data definition, the SQL data definition utility automatically updates the system tables.

The temporary system tables allow access to information about the database and its connections and a degree of control over transactions. By default, all users can select from permanent system tables, but only the database owner and the SYSDBA user can write to them. To gain access to temporary system tables, explicit access has to be granted to them by the database owner or the SYSDBA. These users can grant write access to others if they wish. See the Operations Guide for details about system table security.

SQL system views provide information about existing integrity constraints for a database. You must create system views yourself by creating and running an isql script after database definition.

To see system tables, use this isql command:

SHOW SYSTEM TABLES;

The following isql command lists system views along with database views:

SHOW VIEWS;

The Change Views feature uses InterBase multigenerational architecture to capture changes to data. With this feature you can quickly find out what data has changed since you last viewed it. Previously, to find this information, it involved triggers, logging, and/or transaction write-ahead log scraping. It is time-consuming for the developer and affects the database performance for a certain transaction load or change volume. With Change View, there is no performance overhead on existing transactions because it maintains a consistent view of changed data observable by other transactions. See Change Views (Reference) for the code that creates these views.

Advance To: