The syssyntable system catalog table outlines the mapping between each public or private synonym and the database object (table, sequence, or view) that it represents. It contains one row for each entry in the systables table that has a tabtype value of Por S. The syssyntable table has the following columns.
Column Type Explanation
tabid INTEGER Identifying code of the public synonym
servername VARCHAR(128) Name of an external database server
dbname VARCHAR(128) Name of an external database
owner VARCHAR(32) Name of the owner of an external object
tabname VARCHAR(128) Name of an external table or view
btabid INTEGER Identifying code of a base table, sequence, or view

ANSI-compliant databases do not support public synonyms; their syssyntable tables can describe only synonyms whose syssyntable.tabtype value is P.

If you define a synonym for an object that is in your current database, only the tabid and btabid columns are used. If you define a synonym for a table that is external to your current database, the btabid column is not used, but the tabid, servername, dbname, owner, and tabname columns are used.

The tabid column maps to systables.tabid. With the tabid information, you can determine additional facts about the synonym from systables.

An index on the tabid column allows only unique values. The btabid column is indexed to allow duplicate values.