Easysoft ODBC-SQL Server 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.


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.


In an SQL table, the area in each row that stores the data value for some attribute of the object modelled by the table. For example, the Employee table in the AdventureWorks sample database models the employees of the Adventure Works Cycles company. The Title column in each row of the Employee table stores the job title of the employee represented by that row, the same way a Job Title field in a window or form would contain a job title.


An operation that saves all changes to databases, cubes, or dimensions made since the start of a transaction. A commit guarantees that all of the transaction's modifications are made a permanent part of the database, cube or dimension. A commit also frees resources, such as locks, used by the transaction.


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 Encryption Standard (DES)

A specification for encryption of computer data developed by IBM. DES uses a 56-bit key.

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.

Database mirroring

The process of immediately reproducing every update to a read/write database (the principal database) onto a read-only mirror of that database (the mirror database) that resides on a separate instance of the Database Engine (the mirror server).

Database mirroring partners

Two server instances that act as role-switching partners for a mirrored database.

Default database

The database the user is connected to immediately after logging in to SQL Server.

Default instance

The instance of SQL Server that uses the same name as the computer name on which it is installed.

Default language

The language that SQL Server uses for errors and messages if a user does not specify a language. Each SQL Server login has a default language.

Default result set

The default mode that SQL Server uses to return a result set back to a client. Rows are sent to the client in the order in which they are placed in the result set, and the application must process the rows in this order. After running an SQL statement on a connection, the application cannot do anything on the connection except retrieve the rows in the result set until all the rows have been retrieved. The only other action that an application can perform before the end of the result set is to cancel the remainder of the result set. This is the fastest method to get rows from SQL Server to the client.

Distributed query

A single query that accesses data from multiple data sources.

Distributed transaction

A transaction that spans multiple data sources. In a distributed transaction, all data modifications in all accessed data sources are either committed or terminated.


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


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.


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.


In a database mirroring session, the process in which ownership of the principal role is switched from the principal server to the mirror server.


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.


A computer visible on the network.

Identity column

A column in a table that has been assigned the identity property. The identity property generates unique numbers.


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. SQL Server supports clustered and nonclustered indexes. 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.


A copy of SQL Server running on a computer. A computer can run multiple instances of SQL Server 2005 or later. A computer can run only one instance of SQL Server version 7.0 or earlier, although in some cases it can also be running multiple instances of SQL Server 2000.


A data type category that includes the bigint, int, smallint, and tinyint data types.

Isolation level

The property of a transaction that controls the degree to which data is isolated for use by one process, and is guarded against interference from other processes. Setting the isolation level defines the default locking behaviour for all SELECT statements in your SQL Server session.

License key

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

Master database

The system database that records all the system-level information for an instance of SQL Server. This includes instance-wide metadata such as login accounts, endpoints, linked servers, and system configuration settings. Also, master is the database that records the existence of all other databases and the location of those database files and records the initialization information for SQL Server.


A hashing algorithm that creates a 128-bit hash value used to verify data integrity. A hashing algorithm is a mathematical procedure for randomising information to make it more secure in transmission. The more bits in a hash, the greater the security of the encryption process.

Mirror server

In a database mirroring configuration, the server instance on which the mirror database resides.

Multiple instances

Multiple copies of SQL Server running on the same computer. There can be one default instance, which can be any version of SQL Server. SQL Server 2000 or later supports multiple named instances.

Named instance

An installation of SQL Server that is given a name to differentiate it from other named instances and from the default instance on the same computer. A named instance is identified by the computer name and instance name.


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.


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.

Principal server

In database mirroring, the partner whose database is currently the principal database.


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

The set of rows returned from a SELECT statement. The format of the rows in the result set is defined by the column-list of the SELECT statement.


In an SQL table, a single occurrence of the object modelled by the table. For example, in the AdventureWorks sample database, the Employee table models the employees of the Adventure Works Cycles company. Each row in the table records all the information about a specific employee such as an employee identification number, job title, and the date that employee was hired.

Server cursor

A cursor implemented on the server. The cursor itself is built at the server, and only the rows fetched by an application are sent to the client.

Server name

A name that uniquely identifies a server computer on a network. SQL Server applications can connect to a default instance of SQL Server by specifying only the server name. SQL Server applications must specify both the server name and instance name when connecting to a named instance on a server.

Structured Query Language (SQL)

A language used to insert, retrieve, modify, and delete data in a relational database, designed specifically for database queries. SQL also contains statements for defining and administering the objects in a database. SQL is the language supported by most relational databases, and is the subject of standards published by the International Standards Organization (ISO) and the American National Standards Institute (ANSI). SQL Server uses a version of the SQL language called Transact-SQL.


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

A precompiled collection of Transact-SQL statements that are stored under a name and processed as a unit. SQL Server supplies stored procedures for managing SQL Server and displaying information about databases and users. SQL Server-supplied stored procedures are called system stored procedures.

System databases

A set of five databases present in all instances of SQL Server that are used to store system information. The msdb database is used by SQL Server Agent to record information on jobs, alerts, and backup histories. The model database is used as a template for creating all user databases. The tempdb database stores transient objects that only exist for the length of a single statement or connection, such as worktables and temporary tables or stored procedures. The master database stores all instance-level metadata, and records the location of all other databases. The Resource database contains all the system objects that are included with SQL Server, such as system stored procedures and system tables.


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

Tabular Data Stream (TDS)

The SQL Server internal client/server data transfer protocol. TDS allows client and server products to communicate regardless of operating-system platform, server release, or network transport.


A group of database operations combined into a logical unit of work that is either wholly committed or rolled back. A transaction is atomic, consistent, isolated, and durable.