A $$ is an association between two entity types in an $E-R$ diagram.

$$

$$ is a two$-$dimensional table that contains rows and columns, where cells contain a single value, columns contain data of the same data type, the order of rows and columns is unimportant and no two rows may be identical.

A$.n$ lock allows more than one transaction at a time access to a record.

When converting an ER model to a set of tables, each $$ becomes a table. $$

The $$ is the number of entity classes that participate in a relationship in an E$-$R model. $$

The $$ clause of an SQL $$ query allows specific rows to be retrieved from the database.

Because it has databose can be queried to determine such information as the names of all tables created, the column names and data types for the columns within a particular table, the names and types of constraints a user has created, etc.