CAT-REC file

The CAT-REC file (catalog recovery file) serves as a control file for the recovery of the catalog space and the database as a whole. Different variants of the file exist when you work with logging files:

• as the CAT-REC file (original);
  this is created with CREATE CATALOG or with the first COPY of the database provided that the database was created without logging files.
  This variant describes the current state of the original.

• as the CAT-REC copy;
  this is created with COPY CATALOG[_SPACE] or CHANGE-CATLOG and is a defined restart point for the use of replications. Every COPY or CHANGE-CATLOG overwrites any existing copy.
  Up to this version the modifications can be applied to the replication.

• as the CAT-REC file of the replication;
  this is created with CREATE REPLICATION. The file contains all the records up to and including the backup copy used to create the replication.

  This file is needed in two situations:

  • If a REFRESH REPLICATION is to be performed. The difference in the contents of the CAT-REC copy and the CAT-REC file of the replication forms the content of the REFRESH REPLICATION job.

  • If with RECOVER CATALOG USING/TO REPLICATION an original database is repaired, reset or entered in the SQL database catalog using the replication. The replication of the CAT-REC file then becomes the CAT-REC file of the original.

Contents of the CAT-REC file

The CAT-REC file contains records with the following information:

• Identification block
  This contains the identification record and the database name.

• CREATE CATALOG record
  This contains information on the catalog space from BS2000's point of view, e.g. the primary and secondary assignments, the BS2000 password, and the storage medium.

• Records on the SESAM backup copies of the catalog space
  Each record contains information on a specific SESAM backup copy of the catalog space; this information includes the SESAM backup's time stamp, the SESAM backup copy's version number, the name of the SESAM backup copy and the storage medium for the SESAM backup copy.

• Records on the CAT-LOG files
  Each record contains information on a specific CAT-LOG file; this information includes the creation date, the version number of the associated SESAM backup copy of the catalog space, and a sequence number which indicates the CAT- LOG file's number in the sequence of CAT-LOG files for the SESAM backup copy in question.

Each time the catalog space or the database is backed up, SESAM/SQL adds a record pertaining to the relevant SESAM backup copy of the catalog space to the CAT-REC file.
Each time the CAT-LOG file changes (see section “CAT-LOG files” ), SESAM/SQL adds an appropriate record for this CAT-LOG file to the CAT-REC file.

Using the utility monitor, the database administrator can view information on the content of the CAT-REC file. He/she can also maintain the CAT-REC file online or offline (see the “Utility Monitor” manual).

The utility statement der MODIFY enables the database administrator to maintain the CAT-REC file online (see the “SQL Reference Manual Part 2: Utilities”).

Storage medium, primary and secondary assignments

In the case of a database used with logging activated ), SESAM/SQL creates the CAT-REC file during the execution of the utility statement CREATE CATALOG. In the case of a database used without logging, SESAM/SQL creates the CAT-REC file when the first SESAM backup copy is made of the entire database or of the catalog space. The file is created on the storage medium (disk) and the primary and secondary assignments are made in accordance with the information contained in the first CAT-REC media record in the media table.

The default value 12 applies for both primary and secondary assignment of the CAT-REC file.

BS2000 file names

The CAT-REC file has the following file name in BS2000:
user_id.catalog.CAT-REC
user_id.catalog.CAT-REC.COPY
user_id.replication.CAT-REC.REPL

user_id catalog replication

BS2000 user ID Name of the database name of the replication

Backing up the CAT-REC file

The dual recording by volume or dual copy technique is to be used to maintain parallel copies of the CAT-REC file.

A copy of the CAT-REC file is created by COPY CATALOG[_SPACE] or CHANGE-CATLOG. Every COPY or CHANGE-CATLOG overwrites any existing copy. In the event of a RECOVER, the original database can be reset to the status of the CAT-REC copy.

In the case of COPY CATALOG[_SPACE] on magnetic tape cartridge using HSMS, you can specify in the HSMS parameter file whether or not the CAT-REC file should be backed up, too.