in black and white
Main menu
Share a book About us Home
Biology Business Chemistry Computers Culture Economics Fiction Games Guide History Management Mathematical Medicine Mental Fitnes Physics Psychology Scince Sport Technics

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
Previous << 1 .. 12 13 14 15 16 17 < 18 > 19 20 21 22 23 24 .. 76 >> Next

logical logical OR logical

Lexical separator

A character string that can exist between words, constants, and delimiters without changing the meaning of a statement.

Valid lexical separators are:

• Comments

• Blanks

• Return characters (X’0D’)

Introduction to the Teradata RDBMS for UNIX

Teradata RDBMS Architecture

Structured Query Language

Character Sets

Lexical Component Description
Statement separator A character that separates each statement of a multistatement request. The Teradata SQL separator is the semicolon.
Request terminator A character that terminates a request in the body of a macro or that is entered from BTEQ. The Teradata SQL request terminator is the End of Text character for macros or the semicolon for BTEQ.

The Teradata RDBMS supports multinational and multibyte character sets in several different environments.

Among the character sets supported are:

• Kanji

• Katakana

• Hiragana

• European languages with characters using the umlaut, tilde, or ring

The RDBMS provides multibyte support for the following operating systems:





Multibyte support exists for the following Teradata software:

• Server-based utilities
• Client-based utilities
• Preprocessor2 (embedded SQL)
• CLIv2

Users control the current character set and collation sequences using SQL statements.


Introduction to the Teradata RDBMS for UNIX
Teradata RDBMS Architecture

Query Facilities



Query Facilities

The Teradata RDBMS supports several different facilities for making interactive or batch queries of the database from a terminal.

These include:

• Basic Teradata Query facility (BTEQ)

• Fourth generation languages

Because SQL is the only language the Teradata RDBMS understands, all application programming facilities ultimately make their queries against the database using the SQL language.

The Basic Teradata Query facility is a SQL formatter/ report generator that allows you to create and perform SQL queries interactively or in batch mode from an interactive terminal.

BTEQ supports the following facilities:

• Multiple Teradata SQL statements per request

• Read from and write to client data files

• Manage multiple sessions per job

• Format output and write sophisticated reports

BTEQ is supported on the following platforms:

• Channel-attached client

• Network-attached client

• Teradata server

Introduction to the Teradata RDBMS for UNIX

Teradata RDBMS Architecture




This topic explains the concepts behind the interprocessor network technology used by the Teradata RDBMS: the BYNET.

BYNET Functions

At the most elementary level, you can look at the BYNET as a bus that loosely couples all the SMP nodes in a multinode system. This view does an injustice to the BYNET, however, because the capabilities of the network range far beyond those of a simple system bus.

The BYNET also possesses high speed logic arrays that provide bidirectional broadcast, multicast, and point-to-point communication and merge functions.

A multinode system has two BYNETs. This both creates a fault tolerant environment and provides for enhanced interprocessor communication. When BYNET traffic becomes particularly heavy, the two BYNETs can handle separate (rather than redundant) traffic. The machine provides load balancing software to optimize this process.

The total bandwidth for each network link to a processor node is 10 megabytes. Because there are two network links per node and because the bandwidth is linearly scalable, the total throughput available for each node is 20 megabytes.

For example, a 16-node 5100M system has 320 megabytes of bandwidth for point-to-point connections.

Total available broadcast bandwidth for any size 5100M system is 20 megabytes.

The BYNET software provides a standard TCP/IP interface for communication among the SMP nodes.

Figure 2-4 illustrates how the BYNET connects individual SMP nodes to create an MPP system in the 5100M configuration.


Introduction to the Teradata RDBMS for UNIX
Teradata RDBMS Architecture


Figure 2-4 How the BYNET connects individual SMP nodes





SMP Nodes

SCSI Busses

Disk Arrays

Virtual Processor Connectivity in Single Node Systems

Single node systems mimic the BYNET with a software emulation called the Vnet. Vnet represents “virtual network.”

Introduction to the Teradata RDBMS for UNIX

Teradata RDBMS Architecture The Access Module Process

The Access Module Process

The Access Module Process (AMP) is the heart of the Teradata Introduction RDBMS. The Access Module Process is a virtual processor (vproc)

that provides a BYNET interface and performs many database and file management tasks.

AMPs control the management of the Teradata RDBMS and also provide control over the disk subsystem, with each virtual AMP being assigned to a virtual disk.
Previous << 1 .. 12 13 14 15 16 17 < 18 > 19 20 21 22 23 24 .. 76 >> Next