Determining Scope of URTs
Every CICS program requesting CA Datacom/DB service requires at least one URT defined in the CICS region. For a task to execute, the URT needed for each request must be open or eligible to be opened. During normal operation, all URTs may remain open. During recovery and reload, however, the processing on the databases being recovered or reloaded must be quiesced by closing the URTs which declared them open for access or update.
Note: For more information, see the CA Datacom/DB Database and System Administration Guide.
The contents of URTs can be based on the applications that use them, as in batch. However, for CICS they need not be, since CA Datacom CICS Services makes a URT selection for each request rather than for each application. For example, if a batch program reads data from three databases, the URT you link to that program must define the required tables from each of the three databases. If an online application reads the same three databases, you could define CA Datacom/DB tables for each of these databases in different URTs and CA Datacom CICS Services would select the appropriate one as needed.
Note: You may alter the DCCTFPR exit to control URT selection with a prefix.
Determining Number of URTs to Define
Generally, you define multiple URTs. The amount of time it takes to open and load a URT increases with the quantity of CA Datacom/DB tables within the URT and by the number of URTs to be loaded. This processing time can be included in CICS initialization by:
Defining SQL URTs
CA Datacom CICS Services opens only one URT. If all your programs use SQL, define only one URT containing no CA Datacom/DB tables.
Procedure for Preparing URTs
Your responsibilities include the following:
Note: URT cannot be assembled/linked as RENT.
DEFINE PROGRAM(DBURTnnn)GROUP(B114GRP)LANGUAGE(ASSEM)RESIDENT(YES)CEDF(NO)
Or, in the case of a URT number greater than 999:
DEFINE PROGRAM(DBURnnnn)GROUP(B114GRP)LANGUAGE(ASSEM)RESIDENT(YES)CEDF(NO)
URT Selection
Before accessing CA Datacom/DB, CA Datacom CICS Services passes control to the URT selection module (DCCTFPR). This module determines which URT CA Datacom CICS Services uses when processing a request. Your company may write a prefix CA Datacom CICS Services URT Selection Exit for specific security, or accounting purposes.
Details on the standard URT selection logic are described in URT Selection (DCCTFPR). A simplified explanation of URT selection processing for a non-SQL request follows:
Note: If, within one URT, the same TBLNAM= is specified twice for different DBIDs and has SYNONYM=NO for the first in the list but SYNONYM=YES for the second in the list, CA Datacom/DB finds a match on the first entry and does not look for the second entry. If two URTs have the same TBLNAM= specified for different DBIDs and the lower numbered URT specifies SYNONYM=NO and the higher numbered URT specifies SYNONYM=YES, CA Datacom CICS Services selects the lower numbered URT without regard to DBID.
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