Session Requirements and Availability Check

The integrated command-line documentation utility requires an established database connection to functon. Executing help directives prior to authentication will generate an SP2-0171 availability error.

$ sqlplus /nolog

SQL*Plus: Release 19.0.0.0.0 - Production
...
SQL> help
SP2-0171: HELP system not available.

Authenticate with administrative privileges to initialize the utility:

SQL> connect / as sysdba
Connected.
SQL> help index

Restoring Missing Documentation Tables

If the system remains unresponsive after login, the underlying support scripts are likely absent from the Oracle home. Navigate to the $ORACLE_HOME/sqlplus/admin/help directory and inspect for the core build files:

dir %ORACLE_HOME%\sqlplus\admin\help

 Volume in drive C has no label.
 Directory of C:\app\oracle\product\sqlplus\admin\help

2023-11-05  09:15    278 helpbld.sql
2023-11-05  09:15    356 helpdrop.sql
2023-11-05  09:15  68201 helpus.sql
2023-11-05  09:15  1604 hlpbld.sql

Execute the initialization script within a privileged session to reconstruct the necessary data dictionary objects:

SQL> @?/sqlplus/admin/help/hlpbld.sql helpus.sql

This routine populates the HELP table within the system schema, anabling global access to the reference material.

Verifying Access Across User Profiles

Following successful deployment, the documentation system becomes accessible to all standard database accounts. Validate cross-schema functionality by connecting to a regular user:

SQL> connect scott/tiger
Connected.
SQL> help index

Available Topics:
@             CLEAR         LIST          SET
@@            COLUMN        LOAD          SHOW
ACCEPT        COMPUTE       PASSWORD      SPOOL
...
DESCRIBE      QUIT          STARTUP       WHENEVER SQLERROR
DISCONNECT    RECOVER       VARIABLE      XQUERY

Retrieving Specific Command Syntax

Query individual entries to obtain detailed usage patterns, parameters, and execution rules. For example, examining the script execution operators:

SQL> help @@

@@ (double at sign)
-------------------
Runs a SQL*Plus script file. Functions identically to the single @ command, 
but resolves relative paths relative to the directory of the currently 
executing script rather than the working directory.

Syntax:
@@ {url | file_name[.ext]} [arg ...]

Alternatively, inspect session configuration directives:

SQL> help set

SET [option] [value]
Configures environment variables for the current SQL*Plus session.

Frequently used options:
SET FEEDBACK ON|OFF|{n}
SET LINESIZE {integer}
SET PAGESIZE {integer}
SET TIMING ON|OFF