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.

• How to Declare Entity Integrity
  Once you specify the primary key for each table, no further action is needed by client application developers or by the database administrator to maintain entity integrity.
• How to Enforce Entity Integrity
  When you insert or update a table row, the database server ensures that the primary key for the table is still valid: that each row in the table is uniquely identified by the primary key.
• If a Client Application Breaches Entity Integrity
  Entity integrity requires that each value of a primary key or unique constraint be unique within the table, and that there are no NULL values.
• Referential Integrity
  For the foreign key relationship to be valid, the entries in the foreign key must correspond to the primary key values of a row in the referenced table.
• Loss of Referential Integrity
  Sybase IQ provides protection against referential integrity loss.
• Concurrent Operations
  The referential integrity feature of Sybase IQ restricts concurrent updates or deletes on a primary table during loads or inserts on a foreign table.
• How to Disable Referential Integrity Checking
  You can use the Sybase IQ option DISABLE_RI_CHECK to bypass referential integrity checking if desired.