SQL/MX 2.x Installation and Management Guide (H06.10+, J06.03+)

Adding, Altering, and Dropping SQL/MX Database
Objects
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Dropping SQL/MP Aliases
The RESTRICT option, by default, will not allow a schema to be dropped if the schema
is not empty of specifications for dependent objects. However, the CASCADE option, if
specified, will drop both the schema and any such dependent objects.
If the schema is fairly large and contains many rows, DROP SCHEMA with the
CASCADE might fail with file system error 35, “Unable to obtain an I/O process control
block, or the transaction or open lock unit limit has been reached.” In this case, too
many locks were requested. When this occurs, you need to update
MAXLOCKSPERTCB to 10000 or more.
For more information, see the SQL/MX Reference Manual.
Steps for Dropping a Schema
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 schema that 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 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. For information about using DISPLAY
USE OF, see Checking Module Dependencies with DISPLAY USE OF on
page 11-19 and the SQL/MX Reference Manual.
4. Enter the DROP SCHEMA 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.
For more information and examples of dropping schemas, see the SQL/MX Reference
Manual.
Dropping SQL/MP Aliases
Use the DROP SQLMP ALIAS statement to drop an SQL/MP alias from a schema
(remove its mapping from an SQL/MX ANSI name to a physical SQL/MP file name).
The DROP SQLMP ALIAS statement does not cause the underlying SQL/MP object to
be dropped. Similarly, dropping an underlying SQL/MP object does not cause any
SQL/MP aliases to be dropped. Those aliases remain unchanged and orphaned.
For more information, see the SQL/MX Reference Manual.