This book provides an overview of the IMS Database Recovery Control; facility ( DBRC) and also discusses the administrative and operational. This section contains a description of the DBRC commands. Use these commands to add to, change, and delete information in the RECON and to generate the. DBRC Commands. This chapter contains a description of the DBRC commands. Use these commands to add to, change, and delete information in the.
|Published (Last):||21 June 2014|
|PDF File Size:||15.33 Mb|
|ePub File Size:||6.50 Mb|
|Price:||Free* [*Free Regsitration Required]|
The original data set. The original data set and the copy are a pair of VSAM clusters that work as a pair to record information. If one becomes unavailable, the spare will be activated if it is available.
CONTENTS “DBRC Guide & Reference” IBM Library Server
The best solution, from an availability point of view, is to use rederence three data sets. This is strongly recommended. The first data set is known as copy1.
It contains the current information. DBRC always reads from this data set, and when some change has to be applied, the change is written first to this data set.
BIBLIOGRAPHY.1 “IMS V8 DBRC Guide and Reference” IBM Library Server
The second data set is known as copy2. It contains the same information as the copy1 data set. When the third RECON data set starts to be used, the remaining valid data set is copied to the spare.
When the copy operation is finished, the spare becomes whichever of the data sets was lost, missing, or in error. Change accumulation records track information about change accumulation groups.
This class of records includes change accumulation group, execution, and data set records.
The only record type in this class is a DBDS group record. Subsystem records contain information about the subsystem and related recovery information, including:. This class of records includes:. The fundamental principle behind the RECON data set is referrence store all recovery-related information for a database in one place.
As a general rule, more than one set of RECON data sets is necessary if all the following conditions are true:. The application of the previous rules usually results in the need for at least two different sets of RECON data sets: If this name does not match, DBRC treats this database as if it was not registered. In this case, the test database with a DSN different than the production database, even if with the same DBD name and data set name, can coexist with the production environment, but not under the control of DBRC.
Click here to find out more. The original data set A copy of the original data set A spare data set The original data set and the copy are a pair of VSAM clusters that work as a pair dbc record information.
NHS reference costs 2009-2010 appendix: DBRC organisation-specific reference cost data
The third data set the spare is used in the following cases: Log records Log records track the log data sets used by all subsystems. This class eeference records includes: Change accumulation records Change accumulation records track information about change accumulation groups.
Subsystem records Subsystem records contain information about the subsystem and related recovery information, including: Subsystem name and type online or batch IRLM identification Abnormal-end flag and the recovery-process start flag List of authorized databases Time stamp that correlates the subsystem entry with the appropriate log records Database records Database records track the state of databases, DBDSs, and resources required for recovery of the DBDSs.
As a general rule, more than one set of RECON data sets is necessary if all the following conditions are true: Multiple versions of the same database exist for example, test and production.
The same DBD name is used for the different versions of the database.