SQL/MX 2.x Installation and Management Guide (G06.24+, H06.03+)

Adding, Altering, and Dropping SQL/MX Database
Objects
HP NonStop SQL/MX Installation and Management Guide—523723-004
9-37
Dropping Tables
Steps for Dropping a Table and its Data
1. Start an MXCI session. Enter a LOG command to initiate a log file for statements
and commands entered in this session. Keep the log for your records.
2. Determine the name of the table you wish to drop.
3. Use the DISPLAY USE OF command to identify which user modules are
associated with this object. See the similarity check criteria in the SQL/MX
Programming Manual for C and COBOL and the SQL/MX Programming Manual for
Java to determine if your changes are likely to cause similarly check to fail and
force automatic recompilation. If they will, you should SQL compile these modules
after making the changes to avoid expensive automatic recompilations at run time.
SQL applications that are running while you make these changes will still undergo
automatic recompilation.
For information about explicit and automatic recompilation, see the SQL/MX
Programming Manual for C and COBOL and the SQL/MX Programming Manual for
Java. For information about using DISPLAY USE OF, see Checking Module
Dependencies With DISPLAY USE OF on page 11-20 and the SQL/MX Reference
Manual.
4. Enter the DROP TABLE statement.
5. Revise the application source code as needed to reflect your changes to the
database. Process and compile the updated source file. For more information, see
the SQL/MX Programming Manual for C and COBOL and the SQL/MX
Programming Manual for Java.
For more information and examples of dropping tables, see the SQL/MX Reference
Manual.
Recovering Tables Dropped Accidentally
If you drop a table accidentally, you can recover the table using the DDL file generated
automatically by NonStop SQL/MX. For more information, see Using TMF to Recover
Dropped SQL/MX Objects on page 5-20 and Recovering Tables on page 12-8.
Dropping Table Data Only
To drop data from a table while leaving the table intact, use the PURGEDATA utility.
PURGEDATA drops all data from both tables and their related indexes, or from specific
partitions of tables that have no indexes.
Guidelines for Dropping Table Data Only
•
To use PURGEDATA, you must have ALL privileges on the table you specify
(DELETE, INSERT, SELECT, and UPDATE) and you must own the schema, or
you must be the super ID.