Glossary - Query Scheduler

Teradata Query Scheduler Administrator Guide

Query Scheduler
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Teradata Tools and Utilities



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.


American National Standards Institute. The private, non-profit organization responsible for approving US standards in many areas, including computers and communications.


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. A language and message format used by an application program to communicate with the operating system or some other control program such as a database management system (DBMS) or communications protocol.

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.


American Standard Code for Information Interchange. The basis of character sets used in almost all present-day computers.



Begin Transaction End Transaction. The Transaction mode (option TRANSACT or ‑tr) that implicitly creates transactions for each SQL request if there is not an active transaction. Commands that mark a unit of work that is all updated or all rolled back (not updated).


Basic Teradata Query. A general-purpose, command-based program that allows users on a workstation to communicate with one or more Teradata Database systems, and to format reports for both print and screen output.



Call-Level Interface version 2. The application used by Teradata DWM to connect to the Teradata Database.


CLIv2 system parameter block (SPB) for network-attached systems. The internal SPB, is a data structure that is examined during initialization. During initialization, any DBCAREA values not set in the clispb.dat file by the user will default to the values contained in CLI2SPB.



Database Administrator. Generally, a person responsible for the design and management of one or more databases and for the evaluation, selection and implementation of database management systems.


The default database associated with user DBC. When Teradata Database is first installed on your server, it has only one user. This user is called User DBC and it owns all other databases and users in the system.


A communication structure shared by an application program and CLI. The application uses it to forward control and data information. CLI uses it to return control and data information. An application may use a single DBCAREA or multiple DBCAREAs. CLI retains no knowledge of a particular DBCAREA across multiple CLI calls. CLI is concerned only with the values for DBCAREA that are meaningful to the routine called.


A Database system


Domain Name System. A general-purpose distributed, replicated, data query service chiefly used on Internet for translating hostnames into Internet addresses. Also, the style of hostname used on the Internet, though such a name is properly called a fully qualified domain name. DNS can be configured to use a sequence of name servers, based on the domains in the name being looked for, until a match is found.


exclusion join

In Teradata SQL, a product join or merge join where only the rows that do not satisfy (are NOT in) the conditional specified in the SELECT are joined.

execution time frame

A period of time when Teradata DWM can execute scheduled requests that are waiting to run.



Generic Security Services. An application level interface (API) to system security services. It provides a generic interface to services which may be provided by a variety of different security mechanisms. Vanilla GSS-API supports security contexts between two entities (known as “principals”).



Identifier or Identification.

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.



An individual instance a scheduled request is scheduled to run.


In Teradata SQL, a join is a SELECT operation that allows columns and rows to be combined from two or more tables to produce a result. Join types restricted by Teradata DWM are inner join, outer join, merge join, product join, and all joins. For more information, see all joins, exclusion join, inner join, merge join, nested join, and RowId join.


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.


nested join

In Teradata SQL, this join occurs when the user specifies a field that is a unique primary index on one table and which is in itself an index (unique/non-unique primary or secondary) to the second table.



Open Database Connectivity. An application that may be used by Teradata Tools and Utilities to establish a connection with a Teradata Database.

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.


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 the Priority Scheduler section of Utilities.

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 the other 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.


A profile is a set of parameters assigned to a user, group of users, or an account that determines what scheduling capabilities are available and how your Teradata Query Scheduler scheduled requests server handles their scheduled requests.



A message sent from an application program, such as Teradata DWM, to the Teradata Database. In the Teradata Query Scheduler schedule request environment, a request is the definition of the parameters and text associated with a schedule request.

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 is mapped to a Windows root directory where results are stored.

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.


Rules are the name given to the method used by Teradata DWM to define what requests are prohibited from being immediately executed on the Teradata Database. That is, the rules enforced by Teradata DWM provide the Query Management capabilities.


scheduled requests

The capability to store scripts of SQL requests and execute them at a scheduled time in the future.

self-contained statement

A query request that stores the result data that it generates, if any. For example, an INSERT ... SELECT statement would be self-contained, whereas a SELECT statement would not.


Structured Query Language. An industry-standard language for creating, updating and, querying relational database management systems. SQL was developed by IBM in the 1970s. 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.



The database shared by Teradata Dynamic Workload Manager and Teradata Query Scheduler. Previously called the dbqrymgr database.

Teradata DWM

Teradata Dynamic Workload Manager. A Teradata tool used to create and manage rules that manage access to a Teradata Database.

Teradata QS

Teradata Query Scheduler. A Teradata tool used to schedule SQL requests.

Teradata Tools and Utilities

See TTU.


Teradata Tools and Utilities. A group of products designed to work with the Teradata Database.



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.