Definitions SQL TEST 1 (1) Flashcards
anonymous PL/SQL block
A PL/SQL block that has not been given a specific name.
base table
The table on which a view is based.
batch update routine
A routine that pools transactions into a single batch to update a master table in a single operation.
correlated subquery
A subquery that executes once for each row in the outer query.
CREATE VIEW
A SQL command that creates a logical, virtual table based on stored end-user tables. The view can be treated as a real table.
cross join
A join that performs a relational product of two tables.
cursor
A special construct used in procedural SQL to hold the data rows returned by a SQL query. A cursor may be considered a reserved area of memory in which query output is stored, like an array holding columns and rows. Cursors are held in a reserved memory area in the DBMS server, not in the client computer.
dynamic SQL
An environment in which the SQL statement is not known in advance, but instead is generated at run time. In a dynamic SQL environment, a program can generate the SQL statements that are required to respond to ad hoc queries.
embedded SQL
SQL statements contained within application programming languages such as COBOL, C++, ASP, Java, and ColdFusion.
explicit cursor
In procedural SQL, a cursor created to hold the output of a SQL statement that may return two or more rows, but could return zero or only one row.
host language
Any language that contains embedded SQL statements.
implicit cursor
A cursor that is automatically created in procedural SQL when the SQL statement returns only one value.
inner join
A join operation in which only rows that meet a given criterion are selected. The join criterion can be an equality condition or an inequality condition. The inner join is the most commonly used type of join. Contrast with outer join.
outer join
A relational algebra JOIN operation that produces a table in which all unmatched pairs are retained; unmatched values in the related table are left null. Contrast with inner join.
persistent stored module (PSM)
A block of code with standard SQL statements and procedural extensions that is stored and executed at the DBMS server.
Procedural Language SQL (PL/SQL)
A type of SQL that allows the use of procedural code and in which SQL statements are stored in a database as a single callable object that can be invoked by name.
row-level trigger
A trigger that is executed once for each row affected by the triggering SQL statement. A row-level trigger requires the use of the FOR EACH ROW keywords in the trigger declaration.
set-oriented
Dealing with or related to sets, or groups of things. In the relational model, SQL operators are set-oriented because they operate over entire sets of rows and columns at once.
statement-level trigger
A SQL trigger that is assumed if the FOR EACH ROW keywords are omitted. This type of trigger is executed once, before or after the triggering statement completes, and is the default case.
static SQL
A style of embedded SQL in which the SQL statements do not change while the application is running.
stored function
A named group of procedural and SQL statements that returns a value, as indicated by a RETURN statement in its program code.
stored procedure
1- A named collection of procedural and SQL statements. 2- Business logic stored on a server in the form of SQL code or another DBMS-specific procedural language.
trigger
A procedural SQL code that is automatically invoked by the relational database management system when a data manipulation event occurs.
union-compatible
Two or more tables that share the same column names and have columns with compatible data types or domains.