JDBC Type 4 Driver Programmer's Reference for SQL/MX Release 3.2.1

-drop
Generates SQL statements to drop triggers.
-exec
Executes the SQL statements that are generated.
For example, the following command generates the SQL statements to create the triggers for the
base table sales.paris.pictures, which contains a BLOB column, and executes those
statements. Note: This command must be typed on one line.
java -Dt4sqlmx.blobTableName=sales.paris.lobTable4pictures
com.tandem.t4jdbc.T4LobAdmin
-trigger
-exec sales.paris.pictures
Backing Up and Restoring LOB Columns
For basic information about backing up and restoring databases, see the HP NonStop SQL/MX
Release 3.2.1 Management Guide. That discussion describes the special considerations you must
take for backing up and restoring tables that have LOB columns implemented for the Type 4 driver
(because both base tables and LOB tables are involved).
• When backing up and restoring a base table, make sure that the name of the table is
unchanged. LOB data is not be accessible after restoration if the base table name has changed.
• Triggers cannot be restored by using Backup and Restore 2.0. You can capture the DDL for
the CREATE statements executed for these objects and use this information to manually recreate
these objects after a Restore operation.
• Make sure that the time interval in the backup of the base tables and LOB tables is not large.
A smaller time interval ensures that the data referred to by the base table is present in the LOB
table.
Limitations of LOB Data (CLOB and BLOB Data Types)
Limitations of the CLOB and BLOB data types, collectively referred to as LOB data, are:
• LOB columns can only be in the target column list of these SQL statements:
INSERT statement◦
◦ Select list of a SELECT statement
◦ Column name in the SET clause of an UPDATE statement
• LOB columns cannot be referenced in the SQL/MX functions and expressions.
• LOB data is not deleted from the LOB table when the base row is deleted unless a trigger is
established. For information about triggers, see Using SQL/MX Triggers to Delete LOB Data.
• LOB data is not accessible if the base table name is changed.
• LOB columns cannot be copied to another table by using the SQL/MX utility commands.
• The name of a base table that has CLOB or BLOB columns must be unique across all catalogs
and schemas when more than one of these base tables share a single LOB table.
68 Managing the SQL/MX Tables for BLOB and CLOB Data