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.
Access Module Processor (AMP):
A vproc that receives steps from a PE and performs database functions to retrieve or update data. Each AMP is associated with one vdisk, where the data is stored. An AMP manages only its own vdisk and not the vdisk of any other AMP.
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 Lock:
A lock that is a flag in the table header that effectively rejects certain types of Teradata SQL access statements. An acquisition lock allows all concurrent DML access and the DROP DDL statement, and rejects DDL statements other than DROP.
Acquisition Phase:
Responsible for populating the primary data subtables of the work tables. Data is received from the host, converted into internal format, and inserted into the work tables. The work tables are sorted at the end of the acquisition phase and prior to the application phase.
ANSI:
American National Standards Institute. ANSI maintains a standard for SQL. For information about Teradata compliance with ANSI SQL, see SQL Fundamentals.
Application Lock:
A flag set in the table header of a target table indicating that the application phase is in progress. An application lock allows all concurrent access lock select access and the DROP DDL statement, and rejects all other DML and DDL statements.
Application Phase:
Responsible for turning rows from a work table into updates, deletes, and inserts and applying them to a single target table.
ASCII:
American Standard Code for Information Pronounced as-key. A character set used primarily on personal computers.
B
BTEQ:
Basic Teradata Query. A utility that allows users on a workstation to access data on a Teradata Database, and format reports for both print and screen output. A CLI application program used to interact with the Teradata Relational Database Management System (RDBMS). BTEQ commands are used for controlling sessions, submitting Teradata SQL requests, formatting results, and handling output data. BTEQ may also be used to verify the installation of Teradata client utilities.
C
Call-Level Interface Version 2 (CLIv2):
A library of routines that enable an application program to access data stored in Teradata Database. When used with network-attached clients, CLIv2 contains the following components:
Version 2 of the CLI interface. A collection of callable service routines that provide an interface to a Teradata Database. The interface between the application program and the MTDP (for network-attached clients) or TDP (for mainframe-attached clients).
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, Teradata Database) through a mainframe 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 ANSI.
Checkpoint Rate:
The interval between checkpoint operations during the Acquisition Phase of a Teradata MultiLoad import task expressed as either the number of rows read from the client system or sent to Teradata Database, or an amount of time, in minutes.
Client:
A computer that can access Teradata Database.
COBOL:
COmmon Business-Oriented Language
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.
CPU:
Central processing unit. CPUs are not physically associated with vprocs.
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 Definition Language (DDL):
Supports manipulating database structures and the Data Dictionary information kept about these structures. In Teradata SQL, the statements and facilities that manipulate database structures (such as CREATE, MODIFY, DROP, GRANT, REVOKE, and GIVE) and the Data Dictionary information kept about those structures. In the typical, pre-relational data management system, data definition and data manipulation facilities are separated, and the data definition facilities are less flexible and more difficult to use than in a relational system.
Data Dictionary:
In 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 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 loading:
The process of loading data from a client platform to a Teradata Database server. For Teradata MultiLoad, data loading includes any combination of INSERT, UPDATE, DELETE, and/or UPSERT operations.
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.
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.
Exclusive Lock:
Supports the manual recovery procedure when a RELEASE MLOAD statement is executed after a MultiLoad task has been suspended or aborted.
Exit Routines:
Specifies a predefined action to be performed whenever certain significant events occur during a Teradata MultiLoad job.
F
failure:
Any condition that precludes complete processing of a Teradata SQL statement. Any failure will abort the current transaction.
FastExport:
Teradata FastExport utility. A program that quickly transfers large amounts of data from tables and views of Teradata Database to a client-based application.
FastLoad:
Teradata FastLoad utility. A program that loads empty tables on Teradata Database with data from a network-attached or mainframe-attached client.
field:
The basic unit of information stored in Teradata Database. A field is either null, or has a single numeric or string value. See also column, database, row, table.
Function:
User Defined Functions (UDF) 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. The Teradata Gateway software is the means of communication between the PEs (on the node) and applications running on:
I
import:
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:
Teradata Call-Level Interface Version 2 Reference for Network-Attached SystemsA task that quickly applies large amounts of client data to one or more tables or views on 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 Teradata Database. Routines can be written in C language (for network-attached platforms), or COBOL, PL/I, Assembler, or IBM C (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.
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). The operating system manages interactive (foreground) user requests that initiate units of work. In general, foreground work is given priority over background work.
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 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
lock:
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 FastLoad completes.
M
macro:
a file that is created and stored on Teradata Database, and is executed in response to a Teradata SQL EXECUTE statement
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.
MTDP:
Micro Teradata Director Program. A library of routines that implement the session layer on the workstation. MTDP is the interface between CLI and Teradata Database.
Teradata MultiLoad:
Teradata MultiLoad. A command-driven utility that performs fast, high-volume maintenance functions on multiple tables and views of Teradata Database.
Multiset Tables:
Tables that allow duplicate rows.
MVS (Multiple Virtual Storage):
See z/OS.
N
name:
A word supplied by the user that refers to an object, such as a column, database, macro, table, user, or view.
Network:
In the context of Teradata Database, a LAN (see LAN).
notify exit:
A user-defined exit routine that specifies a predefined action to be performed whenever certain significant events occur during a Teradata MultiLoad job.
For example, by writing an exit in C (without using CLIv2) and using the NotifyExit attribute in an operator definition, a routine can be provided to detect whether a Teradata MultiLoad job succeeds or fails, how many records were loaded, what the return code is for a failed job, and so on.
null:
The absence of a value for a field.
NUPI:
Non-unique primary index; an NUPI is typically assigned to minor entities in the database.
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.
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.
Paused Teradata 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.
PL/I:
Programming Language/1, a programming language supported for Teradata MultiLoad development.
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.
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.
Protocol:
The rules for the format, sequence, and relative timing of messages exchanged on a network.
Q
query:
A Teradata SQL statement, particularly a SELECT statement.
Query Session Utility:
A separate utility program used to monitor the progress of a Teradata MultiLoad job. It reports different sets of status information for each phase of the job.
R
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.
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 utility, such as BTEQ, where the record is packaged with begin- and end-record bytes specific to Teradata Database. Unformatted records are any records not originating on Teradata Database, such as Fortran files. These files contain records that must be defined before loading onto Teradata Database.
Replication Group:
A set of tables for which data changes are being captured on a primary server or applied on a subscriber server.
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 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.
Restoration Lock:
A flag set in the table header of a target table indicating that the table was aborted during the Application Phase and is now ready to be restored. A limited set of operations can be done on the table: Delete All, Drop Fallback, Drop Index, Drop Table, and Select with access lock. No Teradata MultiLoad restart will be allowed on a table with a Restoration Lock.
result:
The information returned to the user to satisfy a request made of Teradata Database.
rule:
Rules are the name given to the method used by DWM to define what requests are prohibited from being immediately executed on Teradata Database. That is, the rules enforced by DWM provide the Query Management capabilities.
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.
S
script:
A file that contains a set of commands and/or SQL statements.
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 Teradata Database. Typically, a Teradata Database server has multiple nodes, which may include both Trusted Parallel Application (TPA) and non-TPA nodes. All nodes of the server are connected using the Teradata BYNET or other similar interconnect.
session:
In client software, a logical connection between an application program on a host and Teradata Database that permits the application program to send one request to and receive one response from Teradata Database at a time.
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 Teradata Database.
SSO:
Single sign-on, an authentication option that allows users of Teradata Database on Windows 2000 systems to access 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 with client applications.
statement:
A request for processing by 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:
A stored procedure is a combination of SQL statements and control and conditional handling statements that run using a single call statement.
T
table:
A set of one or more columns with zero or more rows that consist of fields of related information.
Target table:
A user table where changes are to be made by a Teradata MultiLoad task.
TDPID:
Teradata Director Program Identifier. The name of Teradata Database being accessed.
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.
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. Teradata Database supports both ANSI and Teradata transaction semantics.
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
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 Teradata Database with data types having capabilities not offered by Teradata predefined (built-in) data types. Use Teradata MultiLoad to import values into tables containing UDT columns in the same manner as is done for other tables. The input records to Teradata MultiLoad 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 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.
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.
UTF-16
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 Teradata Database. They are derived from the rows and columns of tables (or other views) whenever the view is referenced.
W
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/OS (MVS (Multiple Virtual Storage)):
One of the primary operating systems for large IBM computers.
z/Linux
Linux operating system (RedHat or SuSE) compiled to run on IBM System z machines.