|Oracle9i SQL Reference
Release 2 (9.2)
Part Number A96540-01
SQL Statements: ALTER CLUSTER to ALTER SEQUENCE, 2 of 21
The tables in the following sections provide a functional summary of SQL statements and are divided into these categories:
Data definition language (DDL) statements enable you to perform these tasks:
DROP commands require exclusive access to the specified object. For example, an
TABLE statement fails if another user has an open transaction on the specified table.
COMMENT commands do not require exclusive access to the specified object. For example, you can analyze a table while other users are updating the table.
Oracle implicitly commits the current transaction before and after every DDL statement.
Many DDL statements may cause Oracle to recompile or reauthorize schema objects. For information on how Oracle recompiles and reauthorizes schema objects and the circumstances under which a DDL statement would cause this, see Oracle9i Database Concepts.
DDL statements are supported by PL/SQL with the use of the
The DDL statements are:
Data manipulation language (DML) statements query and manipulate data in existing schema objects. These statements do not implicitly commit the current transaction. The data manipulation language statements are:
PLAN statements are supported in PL/SQL only when executed dynamically. All other DML statements are fully supported in PL/SQL.
Transaction control statements manage changes made by DML statements. The transaction control statements are:
Session control statements dynamically manage the properties of a user session. These statements do not implicitly commit the current transaction.
PL/SQL does not support session control statements. The session control statements are:
The single system control statement,
SYSTEM, dynamically manages the properties of an Oracle instance. This statement does not implicitly commit the current transaction and is not supported in PL/SQL.
Embedded SQL statements place DDL, DML, and transaction control statements within a procedural language program. Embedded SQL is supported by the Oracle precompilers and is documented in the following books: