A
ABORT:
In Teradata SQL, a statement that stops a transaction in progress and backs out changes to the database only if the conditional expression associated with the abort statement is true.
access lock:
A lock that allows selection of data from a table that may be locked for write access. The Teradata MultiLoad utility maintains access locks against the target tables during the Acquisition Phase.
access module:
A software component that provides a standard set of I/O functions to access data on a specific device.
account:
The distinct account name portion of the system account strings, excluding the performance group designation. Accounts can be employed wherever a user object can be specified.
acquisition phase:
Responsible for populating the primary data subtables of the work tables. Data are received from the host, converted into internal format, and inserted into the work tables. The work tables will be sorted at the end of the Acquisition Phase and prior to the Application Phase.
administrator:
A special user responsible for allocating resources to a community of users.
allocation group:
(AG) A set of parameters that determine the amount of resources available to the sessions assigned to a PG referencing a specific AG. Has an assigned weight that is compared to other AG weights. An AG can limit the total amount of Central Processing Unit (CPU) used by sessions under its control.
ANSI:
American National Standards Institute. ANSI maintains a standard for SQL. For information about Teradata compliance with ANSI SQL, see SQL Fundamentals (B035‑1141).
Application Phase:
Responsible for turning rows from a work table into updates, deletes, and inserts and applying them to a single target table.
API:
Application Program Interface. An interface (calling conventions) by which an application program accesses an operating system and other services. An API is defined at source code level and provides a level of abstraction between the application and the kernel (or other privileged utilities) to ensure the portability of the code.
An API can also provide an interface between a high level language and lower level utilities and services written without consideration for the calling conventions supported by compiled languages. In this case, the API may translate the parameter lists from one format to another and the interpret call‑by‑value and call‑by‑reference arguments in one or both directions.
architecture:
A definition and preliminary design which describes the components of a solution and their interactions. An architecture is the blueprint by which implementers construct a solution which meets the users’ needs.
ASCII:
American Standard Code for Information Interchange, a character set used primarily on personal computers.
B
BTEQ:
Basic Teradata Query facility. A utility that allows users on a workstation to access data on a Teradata Database, and format reports for both print and screen output.
C
capture:
The process of capturing a production data source.
change data capture:
The process of capturing changes made to a production data source. Change data capture is typically performed by reading the source DBMS log. It consolidates units of work, ensures data is synchronized with the original source, and reduces data volume in a data warehousing environment.
mainframe‑attached:
A mainframe computer that communicates with a server (for example, a Teradata Database) through a channel driver.
character set:
A grouping of alphanumeric and special characters used by computer systems to support different user languages and applications. Various character sets have been codified by the American National Standards Institute (ANSI).
Client:
A computer that can access the Teradata Database.
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.
COP:
Communications Processor. One kind of interface processor (IFP) on the Teradata Database. A COP contains a gateway process for communicating with workstations via a network.
COP Interface:
Workstation‑resident software and hardware, and Teradata Database‑resident software and hardware, that allows workstations and the Teradata Database to communicate over networks.
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.
Data Dictionary:
In the Teradata Database, the information automatically maintained about all tables, views, macros, databases, and users known to the Teradata Database system, including information about ownership, space allocation, accounting, and privilege relationships between those objects. Data Dictionary information is updated automatically during the processing of Teradata SQL data definition statements, and is used by the parser to obtain information needed to process all Teradata SQL statements.
data manipulation:
In Teradata SQL, the statements and facilities that change the information content of the database. These statements include INSERT, UPDATE, and DELETE.
Data Model:
A logical map that represents the inherent properties of the data independent of software, hardware, or machine performance considerations. The model shows data elements grouped into records, as well as the association around those records.
data streams:
Buffers in memory for temporarily holding data. A data stream is not a physical file; instead, it is more like a pipe (in UNIX or Windows systems), or a batch pipe in MVS.
Data Warehouse:
A subject oriented, integrated, time‑variant, non‑volatile collection of data in support of management’s decision making process. A repository of consistent historical data that can be easily accessed and manipulated for decision support.
DBA:
Database Administrator
DD:
Data dictionary or data definition.
DEFINE Statement:
A statement preceding the INSERT statement that describes the fields in a record before the record is inserted in the table. This statement is similar to the SQL USING clause.
delimiter:
In Teradata SQL, a punctuation mark or other special symbol that separates one clause in a Teradata SQL statement from another, or that separates one Teradata SQL statement from another.
DLL:
Dynamic‑link library. A feature of the Windows family of operating systems that allows executable routines to be stored separately as files with .dll extensions and to be loaded only when needed by a program.
DML:
Data manipulation language. In Teradata SQL, the statements and facilities that manipulate or change the information content of the database. These statements include SELECT, 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, that is the domain name.
DSN:
Digital Switched Network. The completely digital version of the PSTN.
Duplicate Row Check:
A logic within the Teradata Database used to check for duplicate rows while processing each primary data row for INSERTs and UPDATEs.
DWM:
Dynamic Workload Manager. The product described in this document, which manages access to the Teradata Database.
E
EBCDIC:
Extended binary coded decimal interchange code. An IBM code that uses 8 bits to represent 256 possible characters. It is used primarily in IBM mainframes, whereas personal computers use ASCII.
Error Tables:
Tables created during the Preliminary Phase used to store errors detected while processing a MultiLoad job. There are two error tables, ET and UV, that contains errors found during the Acquisition Phase and Application Phase, respectively.
EOF:
End of File
EON:
Extended Object Names
execution time frame:
A period of time when DWM can execute scheduled requests that are waiting to run.
Exit Routines:
Specifies a predefined action to be performed whenever certain significant events occur during a MultiLoad job.
F
FastExport:
Teradata FastExport utility. A program that quickly transfers large amounts of data from tables and views of the Teradata Database to a client‑based application.
FastLoad:
Teradata FastLoad utility. A program that loads empty tables on the Teradata Database with data from a network‑attached or mainframe‑attached client.
field:
The basic unit of information stored in the Teradata Database. A field is either null, or has a single numeric or string value. See also column, database, row, table.
foreign key:
The primary key of a parent data subject that is placed in a subordinate data subject. Its value identifies the data occurrence in the parent data subject that is the parent of the data occurrence in the subordinate data subject.
formatted records:
See Records.
function:
User Defined Functions (UDFs) are extensions to Teradata SQL. Users can write UDFs to analyze and transform data already stored in their data warehouse in ways that are beyond the functionality of Teradata’s native functions.
G
gateway:
A device that connects networks having different protocols.
global rule:
Object Access and Query Resource rules can be specified as being global, that is, they apply to all objects, and therefore to all requests. When a rule is specified as being global, no query objects need be (or can be) associated with the rule because all objects are implicitly included. Care should be taken defining a global access rule, as it causes all requests to be rejected except those from the DBC user and any bypassed objects.
globally distributed objects (GDO):
A data structure that is shared by all of the virtual processors in the Teradata Database system configuration.
I
import:
This refers to 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.
Import Task:
A task that quickly applies large amounts of client data to one or more tables or views on the Teradata Database. Composed of four major phases: Preliminary, Acquisition, Application, and End. The phases are a collection of one or more transactions that are processed in a predefined order according to the MLOAD protocol. An import task references up to five target tables.
INMOD:
Input Module, a program that administrators can develop to select, validate, and preprocess input data.
INMOD Routine:
User‑written routines that Teradata MultiLoad and other load/export utilities use to provide enhanced processing functions on input records before they are sent to the Teradata Database. Routines can be written in C language (for network‑attached platforms), or COBOL, PL/I or Assembler (for mainframe‑attached platforms). A routine can read and preprocess records from a file, generate data records, read data from other database systems, validate data records, and convert data record fields.
inner join:
In Teradata SQL, a join operation on two or more tables, according to a join condition, that returns the qualifying rows from each table.
instance:
In object‑oriented programming, refers to the relationship between an object and its class. The object is an instance of the class. In Teradata PT, an instance is an occurrence of a fully defined Teradata PT operator, with its source and target data flows, number of sessions, and so on. Teradata PT can process multiple instances of operators.
interface processor (IFP):
Used to manage the dialog between the Teradata Database and the host. Its components consist of session control, client interface, the parser, the dispatcher, and the BYNET. One type of IFP is a communications processor (COP). A COP contains a gateway process for communicating with workstations via a network.
internet protocol (IP):
Data transmission standard; the standard that controls the routing and structure of data transmitted over the Internet.
I/O:
Input/output.
ISO:
International Standards Organization
J
JCL:
Job Control Language is a language for describing jobs (units of work) to the OS/390, z/OS, and VSE operating systems, which run on IBM's OS/390 and z800/900 large server (mainframe) computers. These operating systems allocate their time and space resources among the total number of jobs that have been started in the computer. Jobs in turn break down into job steps. All the statements required to run a particular program constitute a job step. Jobs are background (sometimes called batch) units of work that run without requiring user interaction (for example, print jobs). In addition, the operating system manages interactive (foreground) user requests that initiate units of work. In general, foreground work is given priority over background work.
JIS:
Japanese Industrial Standards specify the standards used for industrial activities in Japan. The standardization process is coordinated by Japanese Industrial Standards Committee and published through Japanese Standards Association.
Job Script:
A job script, or program, is a set of Teradata MultiLoad commands and Teradata SQL statements that make changes to specified target tables and views in the Teradata Database. These changes can include inserting new rows, updating the contents of existing rows, and deleting existing rows.
join:
A select operation that combines information from two or more tables to produce a result.
L
LAN:
Local Area Network. LANs supported by Teradata products must conform to the IEEE 802.3 standard (Ethernet LAN).
Least Used:
Least used (‑lu) in a command line parameter that tells Teradata QD to route queries to the least used database.
Load operator:
A Teradata PT consumer‑type operator that emulates some of the functions of the Teradata FastLoad utility in the Teradata PT infrastructure.
LOB:
An acronym for large object. A large object is a database object that is large in size. LOBs can be up to 2 gigabytes. There are two types of LOBs, CLOBs and BLOBs. CLOBs are character‑based objects, BLOBs are binary‑based objects.
Locks:
Teradata FastLoad automatically locks any table being loaded and frees a lock only after an END LOADING statement is entered. Therefore, access to a table is available when Teradata FastLoad completes.
log:
A record of events. A file that records events. Many programs produce log files. Often a log file determines what is happening when problems occur. Log files have the extension “.log”.
logical action:
A named action that is defined on the Alert Policy Editor's Actions tab. Logical actions can be assigned to events in the alert policy.
Logical Data Model:
A data model that represents the normalized design of data needed to support an information system. Data are drawn from the common data model and normalized to support the design of a specific information system.
Actual implementation of a conceptual module in a database. It may take multiple logical data models to implement one conceptual data model.
loner value:
A value that has a frequency greater than the total number of table rows divided by the maximum interval times 2.
M
macro:
a file that is created and stored on the Teradata Database, and is executed in response to a Teradata SQL EXECUTE statement
merge join:
In Teradata SQL, the type of join that occurs when the WHERE conditional of a SELECT statement causes the system first to sort the rows of two tables based on a join field (specified in the statement), then traverse the result while performing a merge/match process.
Metadata:
Data about data. For example, information about where the data is stored, who is responsible for maintaining the data, and how often the data is refreshed.
methods:
In object‑oriented programming, methods are the programming routines by which objects are manipulated.
NFS:
Network file system.
MIB:
Management Information Base
MOSI:
Micro Operating System Interface. A library of routines that implement operating system dependent and protocol dependent operations on the workstation.
MTDP:
Micro Teradata Director Program. A library of routines that implement the session layer on the workstation. MTDP is the interface between CLI and the Teradata Database.
MultiLoad:
Teradata MultiLoad. A command‑driven utility that performs fast, high‑volume maintenance functions on multiple tables and views of the Teradata Database.
Multiset Tables:
Tables that allow duplicate rows.
MVS (Multiple Virtual Storage):
One of the primary operating systems for large IBM computers.
N
name:
A word supplied by the user that refers to an object, such as a column, database, macro, table, user, or view.
nested join:
In Teradata SQL, this join occurs when a field is a unique primary index for one table of the join and an index (unique or non‑unique primary or secondary index) for the second table in the join.
Network:
In the context of the Teradata Database, a LAN (see LAN).
network attached:
A computer that communicates over the LAN with a server (for example, a Teradata Database).
notify exit:
A user‑defined exit routine that specifies a predefined action to be performed whenever certain significant events occur during a Teradata FastLoad job.
For example, by writing an exit in C (without using CLIv2) and using the NotifyExit attribute in an operator definition, a routine to detect whether a Teradata FastLoad job succeeds or fails, how many records were loaded, what the return code is for a failed job, and so on can be provided.
null:
The absence of a value for a field.
Nullif Option:
This option allows the user to null a column in a table under certain conditions; it is only used in conjunction with DEFINE statements.
NUSI:
Non‑unique secondary index; an NUSI is efficient for range query access, while a unique secondary index (USI) is efficient for accessing a single value.
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 access rule:
An Object Access filter allows defining the criteria for limiting access to issuing objects and/or query objects. Queries that reference objects associated with the rule (either individually or in combination) during the specified dates and times are rejected. Global rules are not applicable for this type.
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, and macros, triggers, join indexes, and stored procedures in a database.
operator routine:
In object‑oriented programming, refers to a function that implements a method.
The terms operator routine and operator function may be used interchangeably.
OS/390
Operating System 390
outer join:
In Teradata SQL, an extension of an inner join operation. In addition to returning qualifying rows from tables joined according to a join condition (the inner join), an outer join returns non‑matching rows from one or both of its tables. Multiple tables are joined two at a time.
owner:
In Teradata SQL, the user who has the ability to grant or revoke all privileges on a database to and from other users. By default, the creator of the database is the owner, but ownership can be transferred from one user to another by the GIVE statement.
P
parameter:
A variable name in a macro for which an argument value is substituted when the macro is executed.
parser:
A program executing in a PE that translates Teradata SQL statements entered by a user into the steps that accomplish the user’s intensions.
parsing engine (PE):
An instance (virtual processor) of the database management session control, parsing, and dispatching processes and their data context (caches).
Paused MultiLoad Job:
A job that was halted, before completing, during the Acquisition Phase of the Teradata MultiLoad operation. The paused condition can be intentional, or the result of a system failure or error condition.
peak perm:
Highest amount of permanent disk space, in bytes, used by a table.
performance groups:
A performance group is a collection of parameters used to control and prioritize resource allocation for a particular set of Teradata Database sessions within the Priority Scheduler. Every Teradata Database session is assigned to a performance group during the logon process. Performance groups are the primary consideration in partitioning the working capacity of the Teradata Database. To learn more about performance groups, see Utilities (B035‑1102).
performance periods:
A threshold or limit value that determines when a session is under the control of that performance period. A performance period links PGs/Teradata Database sessions under its control to an AG that defines a scheduling strategy. A performance period allows AG assignments based on time‑of‑day or resource usage to be changed.
Physical Data Model:
A data model that represents the denormalized physical implementation of data that support an information system. The logical data model is denormalized to a physical data model according to specific criteria that do not compromise the logical data model but allow the database to operate efficiently in a specific operating environment.
PL/I:
Programming Language/1, a programming language supported for MultiLoad development.
Primary server:
A Teradata server in which client applications execute transactions through use of Teradata SQL or utilities such as Teradata MultiLoad and update the tables of one or more replication groups. The changes are captured by Teradata replication services components and given to an Replication intermediary server and processes connected to the Primary server.
priority definition set:
A collection of data that includes the resource partition, performance group, allocation group, performance period type, and other definitions that control how the Priority Scheduler manages and schedules session execution.
product join:
In Teradata SQL, the type of join that occurs when the WHERE conditional of a SELECT statement causes the Teradata Database system to compare all qualifying rows from one table to all qualifying rows from another table. Because each row of one table is compared to each row of another table, this join can be costly in terms of system performance.
Note that product joins without an overall WHERE constraint are considered unconstrained (Cartesian). If the tables to be joined are small, the effect of an unconstrained join on performance may be negligible, but if they are large, there may be a severe negative effect on system performance.
profiles:
A profile is a set of parameters assigned to a user, group of users, or an account that determines which scheduling capabilities are available and how the Teradata Query Scheduler scheduled requests server handles their scheduled requests.
physical action:
A basic action type, such as <Send a Page>, <Send an E‑Mail>, etc. Physical actions must be encapsulated by logical actions in order to be used in the alert policy.
PIC:
Position independent code
PL/I:
Programming Language/1, a programming language supported for MultiLoad development.
PP2:
Preprocessor2
PPP:
Point‑to‑Point Protocol
Primary Key:
A set of one or more data characteristics whose value uniquely identifies each data occurrence in a data subject. A primary key is also known as a unique identifier.
privilege:
A user’s right to perform the Teradata SQL statements granted to him against a table, database, user, macro, or view.
procedure:
Short name for Teradata stored procedure. Teradata provides Stored Procedural Language (SPL) to create stored procedures. A stored procedure contains SQL to access data from within Teradata and SPL to control the execution of the SQL.
production system:
A 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.
Protocol:
The rules for the format, sequence and relative timing of messages exchanged on a network.
Q
query analysis:
A feature that estimates the answer set size (number of rows) and processing time of a SELECT type query.
query:
A Teradata SQL statement, particularly a SELECT statement.
Query Director:
A Teradata client application used to balance sessions between systems according to user provided algorithms.
query management:
The primary function of DWM is to manage logons and queries. This feature examines logon and query requests before they are dispatched for execution within the Teradata Database, and may reject logons, and may reject or delay queries. It does this by comparing the objects referenced in the requests to the types of DBA‑defined rules.
R
Records:
When using the Teradata MultiLoad utility, both formatted and unformatted records are accepted for loading. A formatted record, in the Teradata Database world, consists of a record created by a Teradata Database utility, such as Basic Teradata Query (BTEQ), where the record is packaged with begin‑ and end‑record bytes specific to the Teradata Database. Unformatted records are any records not originating on a Teradata Database, such as Fortran files. These files contain records that must be defined before loading onto the Teradata Database.
Replication Group:
A set of tables for which either data changes are being captured on a primary server or applied on a subscriber server.
Replication Intermediary Server:
The server and computer software process written by a third party which interfaces to one or more Teradata servers and initiates a change data capture or change data apply operation with the Teradata replication services components.
Replication Services Components:
A set of software functions implemented in the Teradata server that capture change data on the tables of a replication group and the Teradata Access Module for Oracle GoldenGate that interact with the Oracle GoldenGate software running on the replication intermediary server.
For detailed information on the replication services components, see Teradata Replication Services Using Oracle GoldenGate and the SQL Data Definition Language.
request:
In host software, a message sent from an application program to the Teradata Database.
resource partition:
A collection of prioritized PGs related by their users’ associations. Has an assigned weight that determines the proportion of resources available to that partition relative to the other partitions defined for that Teradata Database.
Restart Log Table:
One of four restart tables the Teradata MultiLoad utility creates that are required for restarting a paused Teradata MultiLoad job.
result:
The information returned to the user to satisfy a request made of the Teradata Database.
results table/file:
In the Schedule Request environment, a results table or file is a database table or a Windows file into which result data for a schedule request that is not self‑contained are stored.
results file storage:
A symbolic name to a root directory where scheduled requests results are stored. A file storage location can be mapped to a Windows root directory where results are stored.
row:
Whether null or not, that represent one entry under each column in a table. The row is the smallest unit of information operated on by data manipulation statements.
RowID join:
In Teradata SQL, this join occurs when one of the join tables has a non‑unique primary index constant, and another column of that table matches weakly with a non‑unique secondary index column of the second table.
RT:
Response Time
RTF:
Rich Text File
rule:
Rules are the name given to the method used by DWM to define what requests are prohibited from being immediately executed on the Teradata Database. That is, the rules enforced by DWM provide the Query Management capabilities.
run file:
A script that is not contained within the SYSIN file, but rather executed through use of the .RUN BTEQ command.
S
scheduled requests:
The capability to store scripts of SQL requests and execute them at a scheduled later time.
schema:
Schemas are used to identify the structure of the data. Producers have an output schema, to define what the source data will look like in the data stream. Consumers have an input schema, to define what will be read from the data stream. If the input and output schemas are the same, only define the schema once.
script:
A file that contains a set of BTEQ commands and/or SQL statements.
Security token:
A binary string generated by a server when a replication group is created or altered that must be input to secure a change data capture or apply operation.
separator:
A character or group of characters that separates words and special symbols in Teradata SQL. Blanks and comments are the most common separators.
server:
A computer system running the Teradata Database. Typically, a Teradata Database server has multiple nodes, which may include both TPA and non‑TPA nodes. All nodes of the server are connected via the Teradata BYNET or other similar interconnect.
Session:
A session begins when the user logs on to the Teradata Database and ends when the user logs off the Teradata Database. Also called a Teradata Database session.
session:
In client software, a logical connection between an application program on a host and the Teradata Database that permits the application program to send one request to and receive one response from the Teradata Database at a time.
skew:
This value is calculated based on a single Database collection interval. If the Session Collection rate is 60, then the skew is calculated for a 60‑second period.
The value is calculated using 'current' data values. For example, the Max CPU used during the past 60 seconds relative to the Average used over that same 60 seconds:
skew = 100 * (1 – avg / max)
Source Database:
The database from which data will be extracted or copied into the Data Warehouse.
SQL:
Structured Query Language. An industry‑standard language for creating, updating and, querying relational database management systems. SQL was developed by IBM in the 1970s for use in System R. It is the de facto standard as well as being an ISO and ANSI standard. It is often embedded in general purpose programming languages.
Programming language used to communicate with the Teradata Database.
SSO:
Single sign‑on, an authentication option that allows users of the Teradata Database on Windows 2000 systems to access the Teradata Database based on their authorized network usernames and passwords. This feature simplifies the procedure requiring users to enter an additional username and password when logging on to Teradata Database via client applications.
statement:
A request for processing by the Teradata Database that consists of a keyword verb, optional phrases, operands and is processed as a single entity.
statistics:
These are the details of the processes used to collect, analyze, and transform the database objects used by a given query.
stored procedure:
Teradata Version 2 Release 4 and later supports stored procedures. A stored procedure is a combination of SQL statements and control and conditional handling statements that run using a single call statement.
Subscriber server:
A Teradata server in which changes captured from a primary server by an intermediary are applied to tables that duplicate those of the primary. Replication services components executing on the servers provide the capture and apply functions.
supervisory user:
In Data Dictionary, a user who has been delegated authority by the administrator to further allocate Teradata Database resources such as space and the ability to create, drop, and modify users within the overall user community.
T
table:
A set of one or more columns with zero or more rows that consist of fields of related information.
Target Database:
The database in which data will be loaded or inserted.
Target table:
A user table where changes are to be made by a Teradata MultiLoad task.
TCP/IP:
Transmission Control Protocol/Internet Protocol.
Teradata SQL:
The Teradata Database dialect of the relational language SQL, having data definition and data manipulation statements. A data definition statement would be a CREATE TABLE statement and a data manipulation statement would be a data retrieval statement (a SELECT statement).
TDP:
Teradata Director Program; TDP provides a high‑performance interface for messages communicated between the client and the Teradata system.
TDPID:
Teradata Director Program Identifier. The name of the Teradata Database being monitored.
Target Level Emulation (TLE):
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.
test system:
A Teradata Database where Optimizer‑specific information is imported to emulate a target system and create new queries or test new features.
title:
In Teradata SQL, a string used as a column heading in a report. By default, it is the column name, but a title can also be explicitly declared by a TITLE phrase.
TPA:
Trusted Parallel Application.
Transport:
The process of extracting data from a source, interfacing with a destination environment, and then loading data to the destination.
transaction:
A set of Teradata SQL statements that is performed as a unit. Either all of the statements are executed normally or else any changes made during the transaction are backed out and the remainder of the statements in the transaction are not executed. The Teradata Database supports both ANSI and Teradata transaction semantics.
trigger:
One or more Teradata SQL statements associated with a table and executed when specified conditions are met.
TTU:
Teradata Tools and Utilities is a robust suite of tools and utilities that enables users and system administrators to enjoy optimal response time and system manageability with there Teradata system. Teradata FastLoad is included in Teradata Tools and Utilities.
tuple:
In a database table (relation), a set of related values one for each attribute (column). A tuple is stored as a row in a relational database management system. It is analogous to a record in a non relational file.
type:
An attribute of a column that specifies the representation of data values for fields in that column. Teradata SQL data types include numerics and strings.
U
UDF
User Defined Functions
UDM
User‑Defined Methods. The database developer can create custom functions that are explicitly connected to UDTs; these are known as UDMs. Functionalities directly applicable to a UDT can be located within the UDMs associated with that UDT rather than being replicated to all of the applications that use that UDT, resulting in increased maintainability.
UDT
A custom data type, known as a user‑defined type. By creating UDTs, a database developer can augment the Teradata Database with data types having capabilities not offered by Teradata predefined (built‑in) data types. Use Teradata FastLoad to import values into tables containing UDT columns in the same manner as is done for other tables. The input records to Teradata FastLoad must have the column data for UDT columns in its external type format.
Unicode:
A fixed‑width (16 bits) encoding of virtually all characters present in all languages in the world.
unique secondary index (USI):
One of two types of secondary indexes. A secondary index may be specified at table creation or at any time during the life of the table. It may consist of up to 16 columns. To get the benefit of the index, the query has to specify a value for all columns in the secondary index. A USI has two purposes: It can speed up access to a row which otherwise might require a full table scan without having to reply on the primary index, and it can be used to enforce uniqueness of a column or set of columns.
user:
In Teradata SQL, a database associated with a person who uses the Teradata Database. The database stores the person’s private information and accesses other Teradata Databases.
UPI:
Unique primary index; a UPI is required and is typically assigned to major entities in the database.
user:
A database associated with a person who uses the Teradata Database. The database stores the person’s private information and accesses other Teradata Databases.
user groups:
A group of users can be specified within DWM as either as a collection of individual users, or as all user names which satisfy a character string pattern (such as SALE*). The Teradata concept of roles is not used to define user groups, as it applies to privileges. User groups can generally be employed wherever an issuing object can be specified, and any condition applied to a group implicitly applies to all users within that group.
UTF‑8:
In simple terms, UTF‑8 is an 8 bit encoding of 16‑bit Unicode to achieve an international character representation.
In more technical terms, in UTF‑8, characters are encoded using sequences of 1 to 6 octets. The only octet of a sequence of one has the higher‑order bit set to 0, the remaining 7 bits are used to encode the character value. UTF‑8 uses all bits of an octet, but has the quality of preserving the full US‑ASCII range. The UTF‑8 encoding of Unicode and UCS avoids the problems of fixed‑length Unicode encodings because an ASCII file encoded in UTF is exactly same as the original ASCII file and all non‑ASCII characters are guaranteed to have the most significant bit set (bit 0x80). This means that normal tools for text searching work as expected.
UTF16
A 16‑bit Unicode Translation Format.
V
Varbyte:
A data type that represents a variable‑length binary string.
Varchar:
A data type that represents a variable‑length non‑numeric character.
Vargraphic:
A data type that represents a variable‑length string of characters.
view:
An alternate way of organizing and presenting information in a Teradata Database. A view, like a table, has rows and columns. However, the rows and columns of a view are not directly stored by the Teradata Database. They are derived from the rows and columns of tables (or other views) whenever the view is referenced.
VM (Virtual Machine):
One of the primary operating systems for large IBM computers.
VM/CMS
Virtual Machine/Conversational Monitor System
W
workgroups:
Workgroups represent collections of related scheduled request work for users, user groups, or accounts. Each workgroup is assigned a maximum number of requests that can be executing from that workgroup simultaneously thereby ensuring that requests for all workgroups get a fair share of their scheduled work done within the execution time frames.
workload limits rule
A Workload Limits rule allows limiting the number of logon sessions and all‑AMP queries, as well as reject or delay queries when workload limits are encountered. Which users, accounts, performance groups, or users within performance groups that are associated with this type of rule can be defined.
Workstation:
A network‑attached client.
Work Table:
A table created during the Preliminary Phase used to store intermediate data acquired from the host during an MLOAD task. These data will eventually be applied to a target table.
Write Lock:
A write lock enables a single user to modify a table. The Teradata MultiLoad utility maintains write locks against each target table during the Application Phase, and work tables and error tables for each task transaction.
X
XML:
XML is the eXtensible Markup Language, a system created to define other markup languages. For this reason, it can also be referred to as a metalanguage. XML is commonly used on the Internet to create simple methods for the exchange of data among diverse clients.
Z
z/Linux:
Linux operating system (RedHat or SuSE) compiled to run on IBM System z machines.
z/OS (MVS (Multiple Virtual Storage) )
One of the primary operating systems for large
IBM computers.