Under normal circumstances, text and binary data is formatted and added to an SQL statement for execution by the Oracle Server. The formatting of the data is automatically handled by the DBTools.h++ Oracle access library. However, when large character and binary data is provided to the RWDBCursor, RWDBInserter or RWDBUpdater classes, the DBTools.h++ Oracle access library uses another method to bind the data to the statement, which allows larger values to be inserted and updated.
The OCI documentation suggests there is a limitation as to the lengths of large character or binary data. This is also true for allocations of memory within a specific operating system. In either case, the Oracle access library returns RWDBStatus::notSupported if the implementation cannot process the given data because the length exceeds the capabilities of OCI. In 16-bit DOS implementations this limits the size of large character or binary data to 64K.
Oracle also has limitations on using large character and binary data. Only one LONG or LONG RAW column can be specified per table. LONG or LONG RAW columns cannot be used in conditional clauses, i.e., WHERE, etc. However, selecting more than one LONG or LONG RAW column is possible through joins of tables.
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