Micro Focus Server Enterprise Edition for UNIX > Mainframe Support for Deployed Applications > MSS Configuration and Administration > IMS Support > Setting Checkpoints and Using Batch Backout > IMS Batch Backout > Rebuilding Corrupted Databases

Rebuilding Corrupted Databases

When a database file has become corrupt, you must re-build it. This situation is rare, but can occur if, for example, the file was open during a system crash.

To rebuild a corrupted database, use JCL submission executing the database utility program: MFDBUJCL

With MFDBUJCL:

The SYSIN data can specify a fully qualified database file or just the database file name.
Specify REBUILD as the parameter.
Use SYSIN data to name the file to be rebuilt and, optionally, an output file.
With these files, the file extension, .DAT may be specified or not. If not specified, it is automatically appended.
The OUTPUT file is optional. If it is not included, then the database file is rebuilt in place.
If you specify an OUTPUT file, then it becomes the rebuilt file and the INPUT file remains unchanged. In this situation, you must make sure that this output file is renamed to the original file name before it can be used.

Note:

If a database file requires a rebuild, then you should consider whether any associated index files should be rebuilt as well.
Make sure that there is enough free space on disk before submitting the rebuild job.
You will need as much space as the file to be rebuilt requires, and if you have specified an OUTPUT file to be created in the same directory, then you need to account for the extra space requirement.

An example of JCL for restoring a corrupted database is below:

  //DBUJCL01 JOB 'IMS DATABASE UTILITY',CLASS=A,MSGCLASS=A
//*--------------------------------------------------------------------
//* Copyright (C) 1991-2010 Micro Focus (IP) Limited.
//* All rights reserved.
//*-------------------------------------------------------------------
//*
//* THIS JOB REBUILDS THE IMS DEMONSTRATION DATABASE
//* 'DBDNP' USING THE IMSDBU JCL INTERFACE MFDBUJCL.
//*
//*
//STEP01  EXEC PGM=MFDBUJCL,PARM='REBUILD'
//SYSOUT  DD SYSOUT=*
//SYSIN   DD *
INPUT=DBDNP.DAT
OUTPUT=DBDNP.OUT.DAT
/*     
//