Send messages between stored procedures, packages, and triggers.
This package is especially useful for displaying PL/SQL debugging information.
Subprocedures: ENABLE Enable message output. DISABLE Disable message output. PUT Place a line in the buffer. PUT_LINE Place a partial line in buffer. NEW_LINE Terminate a line created with PUT. GET_LINE Retrieve one line from the buffer. GET_LINES Retrieve an array of lines from buffer.
dbms_output.PUT_LINE has a limit of 255 characters, to display more than this, use the alternative procedure available at René Nyffenegger's website: procedure put_line
For full documentation of the packaged procedures above see the Oracle Manual:
"Oracle9i Supplied PL/SQL Packages and Types Reference"
or the book Oracle Built in Packages by Steven Feuerstein et al