Easysoft ODBC-DB2 Driver User's Guide - Glossary

Terms and definitions

Application Programmer Interface (API)

A published set of function calls and constants allowing different programmers to utilize a ready-written library of subroutines.

Authorization code

You must have an authorization code for the Easysoft product you wish to license in order to obtain a purchased license. When you purchase a product your authorization code is emailed to you. You do not need an authorization code to obtain a trial license.

Batch

A set of SQL statements submitted together and run as a group. A script is often a series of batches submitted one after the other.

Column

The vertical component of a database table. A column has a name and a particular data type (for example, character, decimal, or integer).

Commit

To end a unit of work by releasing locks so that the database changes made by that unit of work can be perceived by other processes. This operation makes the data changes permanent.

Cursor

An entity that maps over a result set and establishes a position on a single row within the result set. After the cursor is positioned on a row, operations can be performed on that row, or on a block of rows starting at that position. The most common operation is to fetch (retrieve) the current row or block of rows.

Data Definition Language

The subset of SQL statements that define all attributes and properties of a database and its objects. DDL statements typically start with CREATE, ALTER, or DROP.

Data Manipulation Language

The subset of SQL statements that is used to retrieve and manipulate data. DML statements typically start with SELECT, INSERT, UPDATE, or DELETE.

Data source

A database or other data repository coupled with an ODBC Driver, which has been given a Data Source Name (see DSN) to identify it to the ODBC Driver Manager.

Data type

An attribute that specifies what type of information can be stored in a column, parameter, or variable.

DBMS

Database Management System -- software that handles access to a database.

Distributed query

A single query that accesses data from multiple data sources.

Distributed Relational Database Architecture (DRDA)

The architecture that defines formats and protocols for providing transparent access to remote data.

Driver

See ODBC driver.

Driver Manager

Software whose main function is to load ODBC drivers. ODBC applications connect to the Driver Manager and request a data source name (DSN). The Driver Manager loads the driver specified in the DSN's configuration file. On Windows, the ODBC Data Source Administrator is used to set up the Driver Manager.

DSN

Data Source Name. A name associated with an ODBC data source. Driver Managers, such as unixODBC or the Microsoft Windows Driver Manager, use the Data Source Name to cross-reference configuration information and load the required driver.

DSN-less connection

A type of data connection that is created based on information in a data source name (DSN), but is stored as part of a project or application. DSN-less connections are especially useful for Web applications because they let you move the application from one server to another without re-creating the DSN on the new server.

Field

A placeholder for a single datum in a record, for example you can have a Surname field in a Contact Details record. Fields are sometimes referred to as cells.

Host

A computer visible on the network.

Index

In a relational database, a database object that provides fast access to data in the rows of a table, based on key values. Indexes can also enforce uniqueness on the rows in a table. The primary key of a table is automatically indexed. In full-text search, a full-text index stores information about significant words and their location within a given column.

Isolation level

An attribute that defines the degree to which an application process is isolated from other concurrently executing application processes. Isolation levels generally relate to the behavior of an application with respect to locks.

License key

A string that is provided by Easysoft for use in the licensing process.

NULL

An entry that has no explicitly assigned value. NULL is not equivalent to zero or blank. A value of NULL is not considered to be greater than, less than, or equivalent to any other value, including another value of NULL.

ODBC

Open Database Connectivity -- a programming interface that enables applications to access data in database management systems that use Structured Query Language (SQL) as a data access standard.

ODBC driver

Software that accesses a proprietary data source, providing a standardized view of the data to ODBC.

Record

A group of related fields (columns) of information treated as a unit. A record is more commonly called a row in a relational database.

Result set

A set of row values as returned by, for example, a cursor or procedure.

Row

The horizontal component of a table, consisting of a sequence of values, one for each column of the table.

Structured Query Language (SQL)

A standardised language for defining and manipulating data in a relational database.

SQL-92

The version of the SQL standard published in 1992. The international standard is ISO/IEC 9075:1992 Database Language SQL. The American National Standards Institute (ANSI) also published a corresponding standard (Data Language SQL X3.135-1192), so SQL-92 is sometimes referred to as ANSI SQL in the United States.

Stored procedure

An application program, possibly containing SQL statements, that is stored on the database server and can be invoked with the SQL CALL statement.

Table

A data set in a relational database, composed of rows and columns.

Transaction

An atomic series of SQL statements that make up a logical unit of work. All of the data modifications made during a transaction are either committed together as a unit or rolled back as a unit.