Overview of DBMS_OUTPUT

The DBMS_OUTPUT system package allows users to send messages from stored procedures, packages, and triggers.

This system package is commonly used for debugging and displaying PL/SQL debugging information.

Using the PUT and PUT_LINE stored procedures of the DBMS_OUTPUT system package, you can place information in a buffer for other triggers, stored procedures, or packages to read. In separate PL/SQL subprograms or anonymous blocks, you can call GET_LINE or GET_LINES to display the buffered information.

Considerations

• If you do not call GET_LINE, the buffered messages will be ignored.

• Avoid calling the DISABLE or ENABLE stored procedures in application code, as it may affect the control of output by external tools.

  Notice

  Information output by DBMS_OUTPUT is sent only after the subprogram or trigger has completed execution. Currently, there is no mechanism to send DBMS_OUTPUT information in real time to the client.

Data structures of DBMS_OUTPUT

The DBMS_OUTPUT system package defines the CHARARR table type and the DBMSOUTPUT_LINESARRAY object type, which are used together with the GET_LINES stored procedure.

CHARARR table type

The CHARARR table type is used together with GET_LINES to retrieve text submitted by PUT and PUT_LINE.

Syntax:

TYPE CHARARR IS TABLE OF VARCHAR2(32767) INDEX BY BINARY_INTEGER;

DBMSOUTPUT_LINESARRAY object type

The DBMSOUTPUT_LINESARRAY object type is a package-defined type that is used together with GET_LINES to retrieve text submitted by PUT and PUT_LINE.

Syntax:

TYPE DBMSOUTPUT_LINESARRAY IS
VARRAY(2147483647) OF VARCHAR2(32767);

Overview of DBMS_OUTPUT subprograms

The following table lists the DBMS_OUTPUT subprograms supported in the current version of OceanBase Database and their brief descriptions.