Data Integrity

Table and column constraints and appropriate data type selection ensure that the data in your database is valid and reliable.

• Data Integrity Overview
  For data to have integrity means that the data is valid—that is, correct and accurate—and that the relational structure of the database is intact. The relational structure of the database is described through referential integrity constraints, business rules that maintain the consistency of data between tables.
• Column Defaults Encourage Data Integrity
  Column defaults automatically assign a specified value to a particular column or set of columns whenever someone enters a new row into a database table.
• Table and Column Constraints
  Constraints help to ensure that the data entered in the table is correct and provide information to Sybase IQ that boosts performance.
• Entity and Referential Integrity
  The relational structure of the database enables the database server to identify information within the database. Sybase IQ also ensures that primary key-foreign key relationships between tables are properly upheld by all the rows in any join index relying on these relationships.
• Integrity Rules in the System Tables
  All the information about integrity checks and rules in a database is held in the following system tables and views: