Defining Fast Path DEDB buffer pools for multi-area structures

You can enable all DEDB areas that share a single coupling facility structure to use the same buffer pool. This topic describes control statements in the DFSVSMxx member that you use to define Fast Path DEDB buffer pools for multi-area structures.

Control statements for defining Fast Path DEDB buffer pools for multi-area structures

The format of the control statements for defining a Fast Path buffer pool for a multi-area structure is:

Read syntax diagramSkip visual syntax diagramDEDBMAS= ,(poolname,cisize,pbuf,sbuf,maxbuf,LKASID,NOLKASID,strname)

Parameter descriptions for defining Fast Path DEDB buffer pools for multi-area structures

DEDBMAS=
Defines a Fast Path buffer pool that is to be used by a multi-area structure.
poolname
The 1- to 8-character name for the pool. The poolname is used as identification on display terminals and reports.
cisize
The control interval size of the area. All areas that share a multi-area structure must have the same control interval size. If there is a discrepancy between the control interval size of the area used in creating the structure and the control interval size of the area attempting to share the structure, the open process for the area attempting to share the structure fails.
pbuf
The primary buffer allocation. Specify a value from 1 to 32,766.
sbuf
The secondary buffer allocation. Specify a value from 1 to 9999. This secondary allocation is used when the primary allocation runs low.
maxbuf
The maximum number of buffers allowed for this pool. It is a combination of PBUF plus some iteration of SBUF. The maximum value allowed is 32,767. If maxbuf is specified greater than 32,767, it defaults to 32,767.
LKASID │ NOLKASID
Indicates whether this pool is used as a local cache with buffer lookaside capability.

For VSO DEDB areas that use a multi-area structure, whether buffer lookaside is performed must be specified by using the DFSVSMxx PROCLIB member. Specifications using the DBRC batch command INIT.DBDS or CHANGE.DBDS are ignored.

strname
The required 1- to 16-character name of the primary coupling facility structure.
The installation must have defined the structure in the coupling facility resource management (CFRM) administrative policy. The structure name must follow the naming rules of the CFRM. If the name has fewer than 16 characters, the system pads the name with blanks. The valid characters are A-Z, 0-9, and the following special characters:
 $ @ # _
Names must be uppercase and start with an alphabetic character.
Restriction: Avoid using names that IBM® uses for its structures. Do not begin structure names with the letters A-I, or the character string SYS.

Related reading: For more information about shared VSO and multi-area structures, refer to IMS Version 15.4 Database Administration.