INITIAL IOMODE - Teradata Director Program

Teradata® Director Program Reference - 17.20

Deployment
VantageCloud
VantageCore
Edition
Enterprise
IntelliFlex
Lake
VMware
Product
Teradata Director Program
Release Number
17.20
Published
June 2022
Language
English (United States)
Last Update
2023-11-17
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Product Category
Teradata Tools and Utilities

Purpose

Chooses the mode used by TDP to send I/O to the database.

Syntax



where:

EXCP
CP I/O be performed using EXCP
EXCPVR
CP I/O be performed using EXCPVR.
This is the default in the z/OS environment.
IOSDRIVR
CP I/O be performed using a TDP IOS Driver.
This option is only valid in the z/OS environment.

Usage Notes

If no CPs are started, IOMODE is validated but ignored.

Use of IOSDRIVR reduces the I/O path length between TDP I/O tasks and the system I/O supervisor. Use of the option also avoids Supervisor Call (SVC) interrupts by enabling TDP to pass any new I/O request directly to the IOS.

For z/OS, use of EXCPVR or IOSDRIVR, allows 31bit virtual storage for I/O buffers.

For z/OS, use of EXCPVR or IOSDRIVR results in virtual storage for I/O being fixed in real storage while it is allocated, so real storage utilization can be increased. For CCU-type CPs, such storage is dynamically obtained, freed, or cached as needed; for CIC-type CPs, the storage comprises TDP I/O cells.

Example 1: INITIAL IOMODE

INIT IOMODE EXCP

Example 2: INITIAL IOMODE

INITIAL IOMODE EXCPVR

Example 3: INITIAL IOMODE

INIT IOMODE IOSDRIVR