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Introduction to the Teradata® RDBMS for UNIX® Version 2 Release 2.1 - NCR

NCR Introduction to the Teradata® RDBMS for UNIX® Version 2 Release 2.1 - NCR, 1998. - 315 p.
Download (direct link): inntroduktionteradata1998.pdf
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• Hashrow

• Hashbucket

• Hashamp

• Hashbakamp

A-8

Introduction to the Teradata RDBMS for UNIX
How the Teradata RDBMS for UNIX Differs from the Teradata RDBMS for TOS

Additional General Improvements

• The CASE expression, which enables the user to convert a code into a word or a null into a concrete value, or to generate a null value based on information derived from the database.

• The NOWAIT option to the LOCKING modifier, which can be used to abort a transaction that should not wait in a locking queue.

• Improved Optimizer formulas.

• Improvements in path length and addressability.

• Optimization of journal append, resulting in a reduction of the number of data block writes when permanent journals are used.

In the Teradata DBS for TOS, whenever a permanent journal data block is written, the cylinder index is also written.

In the Teradata RDBMS for UNIX, if an existing data block is being appended to, the cylinder index is not written, nearly halving the number of writes for permanent journals.

This significantly reduces the overhead of using permanent journaling.

• Message broadcasts have been changed to point-to-point in many cases. By making messages point-to-point, only the vprocs needing the message are interrupted.

• The sizes of the transactions in progress (TIP) table and lock table have been increased, reducing the likelihood that the system will run out of these internal resources.

• The dictionary cache has been increased, and is user tunable.

• Parsing memory has been increased, with a corresponding increase in size for both plastic steps and concrete steps.

The increase in parsing memory size allows for the execution of larger and more complex queries.

Additionally, parsing memory size is user-tunable; the size can be limited to control system workload as needed.

• User-defined collation.

In the Teradata DBS for TOS, a limited number of collations are supported.

In the Teradata RDBMS for UNIX, the system administrator can define and install custom-defined collation sequences that can be requested at the session level.

• The PDE controls scheduler class groupings and functions for Teradata RDBMS processes via the Fair Share scheduler.

Introduction to the Teradata RDBMS for UNIX

A-9
How the Teradata RDBMS for UNIX Differs from the Teradata RDBMS for TOS

Additional General Improvements

The ACCOUNT clause of the CREATE/MODIFY USER statement can be used to assign a user’s sessions to a particular performance group.

If no performance group is specified for the acctid under which a session is invoked, that session is assigned to the Medium performance group.

• The client software and interfaces for the Teradata RDBMS for UNIX are the same as those for the Teradata DBS for TOS.

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Introduction to the Teradata RDBMS for UNIX
How the Teradata RDBMS for UNIX Differs from the Teradata RDBMS for TOS

How the Teradata RDBMS for UNIX Differs from the Teradata DBS for TOS

How the Teradata RDBMS for UNIX Differs from the Teradata DBS for TOS

The following table highlights the differences between the Teradata DBS for TOS and the Teradata RDBMS for UNIX.

V1 Feature V2 Feature Documentation sources for information
Proprietary Hardware System Open System Introduction to the Teradata RDBMS for UNIX
Teradata Operating System (TOS) Parallel Database Extensions (PDE) and UNIX operating system Introduction to the Teradata RDBMS for UNIX Teradata RDBMS for UNIX Database Design and Administration
AMP, PE, and AP processor boards AMP and PE virtual processor (vproc) software functions Introduction to the Teradata RDBMS for UNIX Teradata RDBMS for UNIX Database Design and Administration Teradata RDBMS for UNIX Support Utilities Reference
Ynet BYNET (MPP) and Vnet (SMP) with vproc migration Introduction to the Teradata RDBMS for UNIX Teradata RDBMS for UNIX Database Design and Administration
Hash Buckets = 3,643 Hash Buckets = 65,536 Introduction to the Teradata RDBMS for UNIX Teradata RDBMS for UNIX Database Design and Administration

Introduction to the Teradata RDBMS for UNIX

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How the Teradata RDBMS for UNIX Differs from the Teradata RDBMS for TOS

How the Teradata RDBMS for UNIX Differs from the Teradata DBS for TOS

V1 Feature V2 Feature Documentation sources for information
Gateway sessions (per AP), maximum = 300 COP sessions (DBC/1012 only), maximum = 120 Gateway sessions, per node maximum = 1200 (user-tunable) Teradata RDBMS for UNIX Database Design and Administration Teradata RDBMS for UNIX Utilities Reference
NVRAM Cliques of two or more nodes with buddy-AMP commit Introduction to the Teradata RDBMS for UNIX
Fallback (to provide data availability after an AMP failure) Cliques of two or more nodes with vproc migration (and fallback option) Introduction to the Teradata RDBMS for UNIX Teradata RDBMS for UNIX Database Design and Administration
Fallback (to provide data protection) RAID disk storage Introduction to the Teradata RDBMS for UNIX Teradata RDBMS for UNIX Database Design and Administration
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