Glossary

Make a data source available to ODBC through the Add operation of the ODBC Administrator utility. Adding a data source tells ODBC where a specific database resides and which ODBC driver to use to access it. Adding a data source also invokes a setup dialog box for the particular driver so you can provide other details the driver needs to connect to the database.

Number of rows in a result table.

Generally, in client/server systems, the part of the system that sends requests to servers and processes the results of those requests.

The version of the Dharma DataLink SDK that implements a network ODBC architecture. In the client/server configuration, the ODBC tool and a Dharma DataLink driver runs on Windows, while the ODBC SDK server runs on the UNIX or NT server hosting the proprietary storage system.

Another term for system catalog.

See ODBC data source

The version of the Dharma DataLink SDK that implements a “single-tier” ODBC architecture. In the desktop configuration, the ODBC tool, the Dharma DataLink SDK software, and the proprietary data all reside on the same Windows computer.

The default owner name for all system tables in a Dharma database. Users must qualify references to system tables as dharma.table-name.

Data that details the structure of tables and indexes in the proprietary storage system. The SQL engine stores metadata in the system catalog.

Any program that calls ODBC functions and uses them to issue SQL statements. Many vendors have added ODBC capabilities to their existing Windows-based tools.

In ODBC terminology, a specific combination of a database system, the operating system it uses, and any network software required to access it. Before applications can access a database through ODBC, you use the ODBC Administrator to add a data source --register information about the database and an ODBC driver that can connect to it -- for that database. More than one data source name can refer to the same database, and deleting a data source does not delete the associated database.

Vendor-supplied software that processes ODBC function calls for a specific data source. The driver connects to the data source, translates the standard SQL statements into syntax the data source can process, and returns data to the application. The Dharma DataLink SDK includes an ODBC driver that provides access to proprietary storage systems underlying the ODBC server.

A Microsoft-supplied program that routes calls from an application to the appropriate ODBC driver for a data source.

The executable that results from building an implementation of the storage interfaces with the SQL engine library. To get started with the ODBC SDK, you can build an ODBC Server from the supplied sample implementation of the storage interfaces. Eventually, you will build an ODBC Server from your own implementation of the storage system to provide access to a proprietary storage system.

A subset of the fields in a table, characterized by the constraint that no two records in a table may have the same primary key value, and that no fields of the primary key may have a null value. Primary keys are specified in a CREATE TABLE statement.

The fundamental element in SQL syntax. Query expressions specify a result table derived from some combination of rows from the tables or views identified in the FROM clause of the expression. Query expressions are the basis of SELECT, CREATE VIEW, and INSERT statements

Another term for result table.

A temporary table of values derived from columns and rows of one or more tables that meet conditions specified by a query expression.

Another term for tuple identifier.

The SQL syntax element that specifies a condition that is true or false about a given row or group of rows. Query expressions and UPDATE statements can specify a search condition. The search condition restricts the number of rows in the result table for the query expression or UPDATE statement. Search conditions contain one or more predicates. Search conditions follow the WHERE or HAVING keywords in SQL statements.

The fraction of a table's rows returned by a query.

Generally, in client/server systems, the part of the system that receives requests from clients and responds with results to those requests.

The core component of the Dharma DataLink server. The SQL engine receives requests from the Dharma DataLink driver, processes them, and returns results.

C routines called by the SQL engine that access and manipulate data in a proprietary storage system. A proprietary storage system must implement supplied storage stub templates to map the storage interfaces to the underlying storage system.

A completed implementation of the Dharma DataLink SDK storage interfaces. A storage manager receives calls from the SQL engine and accesses the underlying proprietary storage system to retrieve and store data.

Another term for stub interfaces.

The proprietary database system that underlies a storage manger. The Dharma DataLink SDK provides a SQL interface to a storage system through the SQL engine and its stub interfaces.

Template routines provided with the Dharma DataLink SDK for implementing access to proprietary storage systems. Once filled in for a particular storage system, the completed stubs are called storage managers.

Another term for stub interfaces.

Tables created by the SQL engine that store information about tables, columns, and indexes that make up the database. The SQL engine creates and manages the system catalog independent of the proprietary storage system.

Another term for system catalog.

Another term for tuple identifier.

A group of database operations whose changes can be made permanent or undone only as a unit.

A unique identifier for a tuple (row) in a table. Storage managers return a tuple identifier for the tuple that was inserted after an insert operation. The SQL engine passes a tuple identifier to the delete, update, and fetch stubs to indicate which tuple is affected. The SQL scalar function ROWID and related functions return tuple identifiers to applications.

A virtual table that recreates the result table specified by a SELECT statement. No data is stored in a view, but other queries can refer to it as if it were a table containing data corresponding to the result table it specifies.