| Access | A popular desktop DBMS by Microsoft. |
| DB2 | A major DBMS from IBM. |
| MySQL | A popular, open-source, RDBMS. |
| Oracle | Perhaps the most extensive (and expensive) (OR)DBMS. |
| PostgreSQL | A popular, open-source, ORDBMS. |
| SQL Server | A RDBMS by Microsoft for servers. |
| DBMS | DataBase Management System |
| hierarchical DBMS | |
| network DBMS | |
| ODBMS | Object-Oriented DBMS (also OODBMS). |
| OODBMS | Object-Oriented DBMS (also ODBMS). |
| ORDBMS | Object-Relational DBMS. A hybrid of the two technologies. |
| RDBMS | Relational DBMS. This is the principle type of DBMS in use today. |
| crow's foot notation | A system of symbols for indicating multiplicity in relational diagrams. |
| ERD | Entity Relation Diagram. |
| cardinality | Same as multiplicity. |
| connectivity | Same as cardinality or multiplicity. A few authors distinguish between these terms, but many don't. |
| many-to-many | Many-to-many relationships can not be directly represented in a relational database, but are replaced by a bridging table. |
| multiplicity | Same as cardinality. |
| one-to-many | The most common type of relation where many foreign key values can reference a primary key. |
| one-to-one | For each primary key there is at most one corresponding foreign key in a referencing table. Commonly used to implement subset relationships or lookup tables. |
| participation | optional or mandatory. |
| recursive | A relationship between a table and itself. Same as self-referential. Commonly used for a part-of relationship or a tree hierarchy. |
| relational diagram | Same as relational schema. |
| relational schema | Same as relational diagram. |
| attribute | Same as column. |
| bridge table | A table needed to implement a M:N relationship between two other tables in a RDBMS. Typically has a composite key using the primary keys of the two other tables. |
| calculated attribute | Same as derived attribute |
| composite key | A key composed of more than one field. |
| data type | Same as domain. |
| derived attribute | Same as calculated attribute |
| domain | The possible values that an attribute may have, eg, INTEGER. Same as data type. |
| entity | Entity has two interpretations. It can mean a record or a table. It has the table meaning in Entity Relation Diagram and bridge entity. |
| file | Same as table. |
| foreign key | A field which links to the primary key. |
| index | A file used internally by the database to speed access to records. An index is usually generated automatically for primary and foreign keys. A user may request other fields that are searched to be indexed. |
| key | A value which is used to link two or more tables. |
| NULL | Value often used to indicate optional, missing, or unknown value. |
| primary key | The unique value which distinguishes every record. |
| record | Same as row, tuple. |
| row | Same as record, tuple. |
| table | Same as file. |
| tuple | Same as record, row. |
| Cartesian product | Same as cross product. |
| cross product | Table formed by joining all possible combinations of the rows of two other tables. This is the basis for most joins (default or inner join). Same as Cartesian product. |
| DDL | Data Definition Language - a language used to define tables, etc. SQL is an example of a DDL. |
| DML | Data Manipulation Language - a language used to access a database. SQL is an example of a DML. |
| join | To combine two or more tables. |
| query | A search of a database. In SQL the SELECT command is used for queries. |
| SQL | Structured Query Language. Pronounced either ess-queue-ell or sequel |
| DBA | DataBase Administrator |
| data dictionary | The metadata about a database. This is, of course, kept in a database, often in the system catalog. |
| metadata | Data about a database, eg the names of the tables and attributes, the attribute domains, etc. This information is typically in the data dictionary. |
| referential integrity | For every foreign key value there must be a corresponding primary key value. |
| system catalog | Metadata database which has information about all databases in DBMS. |