RMAN-Checking the Syntax of RMAN Commands

RMAN-Checking the Syntax of RMAN Commands

Problem:

You want to check the syntax of your RMAN commands without actually executing the commands.

Solution:

To check the syntax of RMAN commands, you must start the RMAN client with the operating system command-line argument checksyntax. You can easily check the syntax of commands prior to their execution either by entering them at the command prompt or by reading in the commands through a command file. Here’s how you check the syntax of a single RMAN command (run {backup database;}) by first starting the RMAN client with the checksyntax argument:

$. /rman checksyntax

Recovery Manager: Release 11.1.0.1.0 - Beta on Mon Apr 2 08:31:11 2007
Copyright (c) 1982, 2005, Oracle. All rights reserved.
RMAN> run {backup database;}
The command has no syntax errors
RMAN>

In this example, there were no errors in the syntax of the simple run block, and RMAN confirms that. You can also use the checksyntax argument to check the syntax of RMAN commands that are part of a command file. Simply specify the checksyntax argument before invoking the command file that consists of the RMAN commands. In the following example,
the file goodcmdfile contains a couple of restore and recovery commands:

$ rman checksyntax @/tmp/goodcmdfile
Recovery Manager: Release 11.1.0.1.0 - Beta on Mon Apr 2 08:31:11 2007
Copyright (c) 1982, 2005, Oracle. All rights reserved.
RMAN> # file with legal syntax
2> restore database;
3> recover database;
4>
The cmdfile has no syntax errors
Recovery Manager complete.
$

You can also open an RMAN session solely for the purpose of checking the syntax of commands
that you type interactively:

$ rman checksyntax

An important point about the checksyntax argument is that you can’t use it after starting RMAN. That is, you can’t include the checksyntax argument from the RMAN command line. You must pass checksyntax as an argument to the rman command when you start the RMAN client and without connecting to any target or recovery catalog.

How It Works
When you either execute an RMAN command file by preceding it with the checksyntax argument or enter any RMAN commands after starting RMAN with the checksyntax argument, RMAN won’t actually execute any RMAN commands. RMAN will check and report only on the syntax of those commands. If the RMAN commands that you type at the command line or that you include as part of a command file have no errors, you get the “the command (cmdfile) has no errors” message from RMAN. Otherwise, RMAN will issue an error, as shown in the following example:

$ rman checksyntax @/tmp/badcmdfile
Recovery Manager: Release 11.1.0.1.0 - Beta on Mon Apr 2 08:31:11 2007
Copyright (c) 1982, 2005, Oracle. All rights reserved.
RMAN> # file with illegal syntax
RMAN> run (backup database);
RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-00558: error encountered while parsing input commands
RMAN-01009: syntax error: found "(": expecting one of: "{"
RMAN-01007: at line 1 column 5 file: standard input
RMAN>

The output of the checksyntax command reveals there is a syntax error in your run block. The checksyntax command is handy for checking scripts for syntax errors. With RMAN, there’s no need for a script to fail unexpectedly because you mangled the syntax of a command. If you’re surprised by an error, it’s because you didn’t test with checksyntax first.