A
access lock
The requestor is willing to accept minor inconsistencies of the data while accessing the database (an approximation is sufficient).
An access lock permits modifications on the underlying data while the SELECT operation is in progress.
access module processor (AMP)
A virtual processor that receives steps from a parsing engine (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.
AMP
See access module processor (AMP).
AP
Application Processor
APRC
application Processor Reset Containment
ARC
Teradata’s Archive/Recovery Utility
B
BTEQ
Basic Teradata Query
build step
Teradata ARC runs a build step for each subtable (primary data, indexes, LOG, LOB columns) that is included as part of a table.
C
Call-Level Interface (CLI)
A programming interface designed to support SQL access to databases from shrink-wrapped application programs. SQL/CLI provides and international standard implementation-independent CLI to access SQL databases. Client-server tools can easily access database through dynamic link libraries. It supports and encourages a rich set of client-server tools.
Column Partitioned (CP) tables
Tables partitioned based on one or more columns.
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 may include, tables, views, macros, triggers, and stored procedures.
DBC
Database computer. Name of database with Teradata Database system tables.
DIP
Database DBC Initialization Procedure
E
exclusive lock
The requester has exclusive rights to the locked resource. No other process can read from, write to, or access the locked resource in any way.
G
GUI
Graphical user interface
I
IFP
Interface Processor
I/O
Input/output
J
JCL
Job Control Language
join
A select operation that combines information from two or more tables to produce a result.
K
KB
Kilobytes
L
LOB
Large object
log
A file that records events. Many programs produce log files. Often a log file is used to determine what is happening when problems occur. Log files have the extension “.log”.
M
multi-stream
The multi-stream feature internally breaks a single job into multiple pieces as streams. This results in multiple sub-jobs, where each stream performs a subset of the work defined in your job. This improves job parallelism, which can increase job performance.
Multi-stream is only available when using a tape backup product. When using the associated GUI to interface with a tape backup product, you can specify how many streams to use for your job. However, if you run ARC from the command line, there is no way to specify multi-stream so you will always run as a single-stream job.
The multi-stream feature is not supported on Mainframe systems.
O
Open Database Connectivity (ODBC)
Under ODBC, drivers are used to connect applications with databases. The ODBC driver processes ODBC calls from an application, but passes SQL requests to the Teradata Database for processing.
P
partitioning expression
The expression defined in the table definition for a table with a partitioned primary index (PPI) that specifies how the data for the table is to be partitioned.
PDE
Parallel Database Extension
PE
Parsing Engine
PPI
Partitioned Primary Index
R
RCC
Recovery Control Catalog
read lock
Several users can hold read locks on a resource, during which time the system permits no modification of that resource.
Read locks ensure consistency during read operations such as those that occur during a SELECT statement.
Relational Database Management System (RDBMS)
A database management system in which complex data structures are represented as simple two-dimensional tables consisting of columns and rows. For Teradata SET, RDBMS is referred to as “Teradata Database.”
S
SQL
See Structured Query Language (SQL).
stream
See Multi-stream.
Structured Query Language (SQL)
The initials, SQL, are pronounced either see-kwell or as separate letters. 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.
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 database.
U
UDF
User-defined function. By providing a mechanism that supports the creation of SQL functions, scalar and aggregate UDFs allow users to add their own extensions to Teradata Database SQL. These functions can be used to operate on any Teradata Database data type and can be utilized wherever built-in functions are used. If a function doesn’t exist to perform a specific task or algorithm, write one that does. UDFs can also simplify complex SQL syntax.
UDT
User-defined type. UDTs introduce object-oriented technology to SQL. Users can define custom data types that model the structures and behaviors of the data in their applications.
UIF
User-installed files. UIFs are user developed scripts written in external language like Ruby, Python, Perl and 'R'.
V
VM
virtual Machine
W
write lock
The requester has exclusive rights to the locked resource, except for readers not concerned with data consistency.