EDMBFIT—Free chain search algorithm

Use the Modify Free Chain Search Algorithm panel or the EDMBFIT command to determine which free chain search algorithm is used on systems with a large EDM pool (greater than 40 MB). 

Important

In the trade-off between performance and space utilization, space is normally more critical for smaller EDM pools and performance is more critical for larger EDM pools. When EDM pool size must be limited, EDMBFIT can be set to Yes to optimize free space utilization. When EDM pool size can be increased, setting EDMBFIT to No optimizes performance.

Modify Free Chain Search Algorithm panel

DDTG DBI1 Modify Free Chain Search Algorithm
Command ===> _________________________________________________________________

 Command: CURRENT
Description . . . . . . . . : FREE CHAIN SEARCH ALGORITHM

Type the new Free Chain Search Algorithm indicator you wish to change to. Then Press Enter.

Free Chain Search Algorithm Indicator
Enabled . . . . . . . . . . (Y or N)

Command syntax and parameters

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Value

Description

DB2ssid

Db2 subsystem ID or the name of the Db2 data sharing group to which the command applies.

opertuneID

OPERTUNE system profile name (if OPERTUNE is running as a started task) or the batch job name (if OPERTUNE is running as a batch job).

Y

The better fit algorithm is used. This value optimizes for better storage use, which is more important for smaller EDM pools.

N

The first fit algorithm is used. This value optimizes for better performance, which is more important for larger EDM pools.

NORESET

The changes you request remain in effect until the Db2 subsystem is cycled.

Db2 parameter values

Field

Installation panel

CLIST parameter

ZPARM macro

ZPARM parameter

Enabled

DSNTIP4

SPRMEBF

DSN6SPRM

EDMBFIT

 

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