15.00 - Glossary - System Emulation Tool

Teradata System Emulation Tool User Guide

prodname
System Emulation Tool
vrm_release
15.00
category
User Guide
featnum
B035-2492-034K

A

Access Module Processor

See AMP.

administrator

A special user responsible for allocating resources to a community of users.

AMP

Access Module Processor. A virtual processor that receives steps from a PE and performs database functions to retrieve or update data. Each AMP is associated with one virtual disk, where the data is stored. An AMP manages only its own virtual disk and not the virtual disk of any other AMP.

C

Call-Level Interface, Version 2

See CLIv2.

CLIv2

Call-Level Interface, Version 2. A programming interface designed to support SQL access to databases from shrink-wrapped application programs. SQL/CLI provides an international-standard, implementation-independent CLI to access SQL databases. Client-server tools can easily access databases through dynamic link libraries. CLI supports a rich set of client-server tools.

column

In the relational model of Teradata SQL, databases consist of one or more tables. In turn, each table consists of fields organized into one or more columns by zero or more rows. All of the fields of a given column share the same attributes. See also database, field, row, and table.

cost

The outlay of database resources used by a given query.

D

database

A related set of tables that share a common space allocation and owner. A collection of objects that provide a logical grouping for information. The objects include tables, views, macros, triggers, and stored procedures. See also column, field, row, and table.

Database System

See DBS.

data definition

The statements and facilities that manipulate database structures and the Data Dictionary information kept about these structures. These statements include CREATE, DROP, ALTER, and MODIFY.

Data Definition Language

See DDL.

Data Dictionary

In Teradata Database, the information automatically maintained about all tables, views, macros, databases, and users known to the Teradata Database system. Includes information about ownership, space allocation, accounting, and access‑right relationships between those objects. Data Dictionary information is updated automatically during the processing of Teradata SQL data‑definition statements. The parser uses the Data Dictionary to obtain information needed to process all Teradata SQL statements.

data manipulation language

See DML.

DBS

Database System

DBS Control information

A group of fields used by Teradata Database for debugging and diagnostic purposes, establishing known global system values, and conducting performance tuning.

DDL

Data Definition Language. In Teradata SQL, the statements and facilities that manipulate database structures (such as CREATE, MODIFY, DROP, GRANT, REVOKE, and GIVE) and the dictionary information kept about those structures. In the typical, prerelational data management system, data definition and data manipulation facilities are separated. The data definition facilities are less flexible and more difficult to use than in a relational system.

DML

data manipulation language. In Teradata SQL, the statements and facilities that manipulate or change the information content of the database. These statements include INSERT, UPDATE, and DELETE.

domain name

A group of computers whose host names (the unique name by which a computer is known on a network) share a common suffix, which is the domain name.

 

Dynamic Plan

The optimizer plan generated incrementally using the dynamic feedback of either the results or statistical information from the intermediate spool tables. See IPE.

E

export

Refers to extracting or transferring system information from the tables and views of a given Teradata Database and saving that information so it can be manipulated or pulled into another system.

F

field

The basic unit of information stored in a Teradata Database. A field is either null or has a single numeric or string value. See also column, database, row, and table.

G

Globally Distributed Object

A data structure that is shared by all of the virtual processors in the Teradata Database system configuration.

I

import

The process of pulling system information into a program. To add system information from an external source to another system. The system receiving the data must support the internal format or structure of the data.

 

IPE

Incremental Planning and Execution. It is an optimizer framework to produce the dynamic plans. The request submitted is fragmented into smaller pieces based on the definition, reliability of cardinality, and cost estimates. The smaller fragments of the request are planned and executed incrementally. The results from the smaller plan fragments are provided as feedback to the planning of the subsequent request fragments, thus generating a more optimal plan.

J

join

A select operation that combines information from two or more tables to produce a result.

L

log

A file that records events. Many programs produce log files, which can be reviewed to determine what is causing a problem. Log files use the file extension .log.

M

macro

A set of Teradata SQL statements stored by Teradata Database and executed by a single EXECUTE statement. Each macro execution is implicitly treated as a transaction.

multi-threading

An option in Teradata SET used to speed up export and import operations with multiple connections.

N

name

A user‑supplied word that refers to an object such as a column, database, macro, table, user, or view.

null

The absence of a value for a field.

O

object

In object-oriented programming, a unique instance of a data structure defined according to the template provided by its class. Each object has its own values for the variables belonging to its class and can respond to the messages or methods defined by its class.

object definition

The details of the structure and instances of the objects used by a given query. Object definitions are used to create the tables, views, macros, triggers, join indexes, and stored procedures in a database.

ODBC

Open Database Connectivity. Under ODBC, drivers are used to connect applications with databases. The ODBC driver processes ODBC calls from an application, but passes SQL requests to Teradata Database for processing.

Open Database Connectivity

See ODBC.

P

parameter

A variable name in a macro for which an argument value is substituted when the macro is executed.

Parent Database box

The Parent Database box specifies the owner for any databases or users created during an import operation. Permanent storage space is taken from the owning database or user for the new database or user. The Parent Database box corresponds to the FROM database_name clause in the CREATE DATABASE and CREATE USER SQL statements. This box establishes a relationship in the hierarchy of ownership.

parser

A program executing in a PE that translates user‑entered Teradata SQL statements into the steps that accomplish the user’s intentions.

Parsing Engine

See PE.

PE

Parsing Engine. An instance (virtual processor) of the database management session control, parsing, and dispatching processes and their data context (caches).

privilege

In Teradata SQL, a user’s right to perform the Teradata SQL statements granted to that user against a table, database, user, macro, or view.

production system

A Teradata Database used in a live environment. A system that is actively used for day‑to‑day business operations. This differs from a test or development system that is used to create new queries or test new features before using them on the production system.

Q

QCD

Query Capture Database. A database of relational tables that store the steps of any query plan captured by the QCF.

QCF

Query Capture Facility. Provides a method to capture and store the steps from any query plan in a set of predefined relational tables called the QCD.

query

A Teradata SQL statement, such as a SELECT statement.

Query Capture Database

See QCD.

Query Capture Facility

See QCF.

R

random AMP sample

See RAS.

RAS

random AMP sample. An arbitrary sample from an AMP. These are samples of the tables in a query or all of the tables in a given database. See also AMP.

Relational Database Management System

See RDBMS.

RDBMS

Relational Database Management System. A database management system in which complex data structures are represented as simple, two‑dimensional tables consisting of columns and rows.

request

In host software, a message sent from an application program to Teradata Database.

result

The information returned to the user to satisfy a request made of Teradata Database.

row

The fields that represent one entry under each column in a table. The row is the smallest unit of information operated on by data‑manipulation statements. See also column, database, field, and table.

S

session

In client software, a logical connection between an application program on a host and Teradata Database. Starting a session permits the application program to send one request at a time to, and receive one response at a time from, Teradata Database.

SET

System Emulation Tool.

Single Sign On

Allows users of Teradata Database on Windows 2000 systems to access the Teradata Database based on their authorized network user names and passwords. This feature simplifies the procedure requiring users to enter an additional user name and password when logging on to Teradata Database using client applications.

SQL

Structured Query Language. Pronounced as separate letters, S Q L. SQL is a standardized query language for requesting information from a database. SQL consists of a set of facilities for defining, manipulating, and controlling data in a relational database.

statement

A request for processing by Teradata Database that consists of a keyword verb, optional phrases, and operands. It is processed as a single entity.

statistics

The details of the processes used to collect, analyze, and transform the database objects used by a given query.

stored procedure

Combinations of procedural and nonprocedural statements run using a single call statement.

Structured Query Language

See SQL.

System Emulation Tool

See SET.

T

table

A two-dimensional structure made up of one or more columns with zero or more rows that consist of fields of related information. See also column, database, field, and row.

target system

A Teradata Database from which Optimizer‑specific information is exported for modeling on a second, test system. Also known as a production system.

Target Level Emulation

See TLE.

test system

A Teradata Database into which Optimizer‑specific information is imported to emulate a target system and create new queries or test new features.

TLE

Target Level Emulation. Permits emulation of a target environment (target system) by capturing system-level information from that environment. The captured information is stored in the relational tables SystemFE.Opt_Cost_Table and SystemFE.Opt_RAS_Table. The information in these tables can be used on a test system with the appropriate column and indexes to make the Optimizer generate query plans as if it were operating in the target system rather than the test system.

trigger

One or more Teradata SQL statements associated with a table and executed when specified conditions are met.

U

UDT

User‑Defined Type. A data type defined by someone other than Teradata. UDTs come in two variations: distinct and structured.

user

A database associated with a person who uses a Teradata Database. The database stores the person’s private information and accesses other Teradata Databases.

User‑Defined Type

See UDT.

V

view

An alternate way of organizing and presenting information in Teradata Database. A view, like a table, has rows and columns. However, the rows and columns of a view are not directly stored by Teradata Database. They are derived from the rows and columns of tables (or other views) whenever the view is referenced.

X

X views

An option in Teradata SET to set a restricted view of plans in the QCD information. See “Customization Options” on page 51.