How to extend a CA Datacom area while the database is open

Document ID : KB000009503
Last Modified Date : 14/02/2018
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Introduction:

When a database area in CA Datacom/AD or CA Datacom/DB becomes full, it is necessary to extend the space allocation to allow more records to be added. If the database definition for that index or data area indicates that Dynamic Extend is allowed, and the file has not reached either its maximum number of extents or the maximum space on the volume, the Multi-User facility will automatically add another extent and prepare it for processing. However, if the size of the extent is either too small or too large, a manual extend must be done. How can this be done while the application is actively processing and without introducing an outage?

Instructions:

With CA Datacom/DB and CA Datacom/AD, an extend of a data area or index area can be performed dynamically, and the size of the extent can be specified without stopping any applications or closing databases. This procedure can be done as long as the file being extended has sufficient available extents and the volume used has sufficient space. In the event the file has reached its maximum number of extents or an additional volume needs to be added to the allocation, this process cannot be used, and the extend must be performed when the database can be closed.

In addition to performing this on-demand extend, this process will also adjust the dynamic extend type and amount so any further automatic dynamic extends will use this new value. This value will remain in effect until the database is closed or the MUF is shut down.

There are certain rules for this process:

  • The area cannot currently be defined as VIRTUAL.
  • The area and database cannot be defined as ACCESS OFF or ACCESS READ or ACCESS UTLTY.
  • The area cannot be the index of the Compound Boolean Selection (CBS) temporary database.
  • The database must have been defined or defaulted in the MUF startup with ACCESS OPTIMIZE.

In other words, the database area to be extended must reside in a disk file, must be currently enabled for standard use and have been defined with ACCESS OPTIMIZE in the MUF startup options, and cannot be used for the CBS database. In addition, this area must have previously been initialized (DBUTLTY command INIT) and must currently be open or able to be opened.

There are three ways to issue this command (called a Console-like command) and examples:

Issuing the command from the console:

/F mufjobname,DYNAMIC_EXTEND 430,IXX,50,TRK

No direct response from the console - see the MUF JES log below for the result =============
Using DBUTLTY in batch mode:

//SYSIN     DD  *
  COMM OPTION=CONSOLE,OPTION2='DYNAMIC_EXTEND 430,IXX,50,TRK'
 /* 
-------------------------------------------------------------------------------------------------
DBUTLTY output:
Date: mm/dd/yyyy   **************************************************************
                   *                                CA Datacom/DB                
Time: hh.mm.ss     *                                General Utility              
                   *                    Copyright . 2009 CA. All rights reserved.
                   **************************************************************
                   
COMM       DBUTLTY COMM CONSOLE COMPLETE - DYNAMIC_EXTEND 430,IXX,50,TRK 

=============
By inserting a record into a specific Datacom System Table using SQL.
Here is an example with DBSQLPR:

//SYSIN    DD  *
   INSERT INTO SYSADM.SQL_CONSOLE
      VALUES('MYMUF','DYNAMIC_EXTEND 430,IXX,50,TRK'); 
/*

DBSQLPR output:

INPUT STATEMENT:
INSERT INTO SYSADM.SQL_CONSOLE
   VALUES('MYMUF','DYNAMIC_EXTEND 430,IXX,50,TRK');

___ SQLCODE=0, SQLSTATE=00000, ROWS AFFECTED=1 ___      

 

In these examples, the command format shows 'DYNAMIC_EXTEND 430,IXX,50,TRK' where:

DYNAMIC_EXTENDis the command entered
430is the DBID to process
IXXis the area in the DBID to process
50is the amount to extend (0 to 65535)
TRKis the type of extent (TRK or CYL). Note that if TRK is specified, and the file is allocated in CYL, the amount is rounded up to the next CYL boundary.

 

If the extend was issued via the console command, you will see these messages in the MUF JES log:

DB01311I - DYNAMIC_EXTEND 430,IXX,50,TRK 
DB01335I - CONSOLE SCHEDULED - DYNAMIC_EXTEND 430,IXX,50,TRK  

 

For all three command options, you will see messages like these in the MUF JES log:

DB01703I - DYNAMIC EXTEND OF AREA IXX00430 STARTED 
DB01701I - DYNAMIC EXTEND OF AREA IXX00430 ENDED, TRACKS BEFORE: 4,350 TRACKS AFTER: 4,410  

 

 

Additional Information:

For more information about the DYNAMIC_EXTEND Console-like command, please refer to the CA Datacom/DB Database and System Administration Guide, in the Introduction Section titled Maintenance using Console Commands.

As always, please contact CA Technologies support for CA Datacom if you have further questions.