JDBC Type 4 Driver 1.1 Programmer's Reference

NULL and Empty BLOB or Empty CLOB Value
Transactions Involving Blob and Clob Access
Access Considerations for Clob and Blob Objects
This chapter describes working with BLOB and CLOB data in JDBC applications. You can use
the standard interface described in the JDBC 3.0 API specification to access BLOB and CLOB
data in NonStop SQL/MX tables with support provided by the Type 4 driver.
BLOB and CLOB are not native data types in an SQL/MX database. But, database administrators
can create SQL/MX tables that have BLOB and CLOB columns by using the Type 4 driver or
special SQL syntax in MXCI as described under Creating Base Tables that Have LOB
Columns.
For management purposes, CLOB and BLOB data is referred to as large object (LOB) data,
which can represent either data type.
Note:
Support for BLOB and CLOB data requires SQL/MX tables.●
BLOB and CLOB data types are not supported when using stored procedures in
Java (SPJs).
●
For information about creating and managing tables for BLOB and CLOB data, see Managing
the SQL/MX Tables for BLOB and CLOB Data.
Architecture for LOB Support
The tables that support LOB data are:
Base table
Referenced by JDBC applications to insert, store, read, and update BLOB and CLOB data.
In the base table, the Type 4 driver maps the BLOB and CLOB columns into a data-locator
column. The data-locator column points to the actual LOB data that is stored in a separate
user table called the LOB table.
LOB table
Actually contains the BLOB and CLOB data in chunks. A Clob or Blob object is
identified by a data locator. LOB tables have two formats: LOB table for BLOB data and
a LOB table for CLOB data.