The sysopclasses system catalog table contains information about operator classes associated with secondary access methods. It contains one row for each operator class that has been defined in the database. The sysopclasses table has the following columns.
Column Type Explanation
opclassname VARCHAR(128) Name of the operator class
owner VARCHAR(32) Name of the owner of the operator class
amid INTEGER Identifying code of the secondary access method associated with this operator class
opclassid SERIAL Identifying code of the operator class
ops LVARCHAR(2048) List of names of the operators that belong to this operator class
support LVARCHAR(2048) List of names of support functions defined for this operator class

The opclassid value corresponds to the sysams.am_defopclass value that specifies the default operator class for the secondary access method that the amid column specifies.

The sysopclasses table has a composite index on the opclassname and owner columns and an index on opclassid column. Both indexes allow only unique values.