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AS/400 supports three large object data types: Binary Large OBjects (BLOBs),<br />
single-byte or mixed Character Large OBjects (CLOBs), and Double-Byte Character<br />
Large OBjects (DBCLOBs). When you copy files that contain these objects using the<br />
Copy <strong>File</strong> (CPYF) command, you should consider the following restrictions and<br />
requirements:<br />
v LOB data is not copied when you copy from and to device files, when you copy<br />
to *PRINT, or when you specify values of *NOCHK or *CVTSRC on the<br />
FMTOPT parameter. In these cases, only the default buffer value for the LOB<br />
field is copied, including ″*POINTER″. This is true even when you copy a file<br />
that contains a LOB field to an identical file. Valid LOB data is copied only<br />
when you have specified *NONE, *MAP, or *DROP on the FMTOPT parameter.<br />
v LOB data is not copied when you copy to a tape or diskette. In these cases, only<br />
the buffer value (including ″*POINTER″) is written to the tape or diskette. In<br />
addition, if you copy from the tape or diskette back to the same file, you may<br />
receive errors; this is because the file contains only the ″*POINTER″ value and<br />
not a valid pointer to actual LOB data.<br />
v When you specify *UPDADD on the MBROPT parameter of the CPYF<br />
command, the to-file can contain a LOB field. LOB fields are also updated when<br />
duplicate keys are encountered.<br />
v When you specify *CVTFLOAT or *NULLFLAGS on the FMTOPT parameter of<br />
the CPYF command, the to-file cannot contain a LOB field.<br />
v If you want to print a file that contains LOB fields, specify *PRINT on the<br />
TOFILE parameter of the CPYF command. ″*POINTER″ will appear in the print<br />
listing in place of the LOB field data, and other non-LOB field data will also<br />
appear in the listing. If you have not specified *PRINT on the TOFILE parameter<br />
and you specified *COPIED, *EXCLUDE, or *ERROR on the PRINT parameter,<br />
then you must specify *NOCHK or *CVTSRC on the FMTOPT parameter for the<br />
copy to be allowed.<br />
v You cannot specify LOB fields on the INCCHAR and INCREL parameters. You<br />
can specify *RCD or *FLD on the INCCHAR parameter, but only the fixed buffer<br />
length is compared, and not any actual LOB data.<br />
v You cannot copy DDM files that contain LOB fields to AS/400 systems running<br />
at Version 4 Release 3 or earlier.<br />
The following tables show how LOBs are mapped to other data types during copy<br />
operations. The first table shows the mapping when both fields contain LOB field<br />
types. In the tables, consider the following guidelines:<br />
v The mapping of LOBs from and to DATE or TIME types is not allowed.<br />
v These mappings are valid only for FMTOPT(*MAP) except where noted.<br />
v There are similar data restrictions for large objects as those for normal character<br />
data (single-byte, mixed, and double-byte).<br />
Table 17. From-file and to-file mapping when both fields are large objects<br />
Field A type Field B type Allowed and Data CCSID or attributes CCSIDs Conversion<br />
copy direction<br />
Field A Field B<br />
translation<br />
performed<br />
BLOB BLOB Y* 65535 65535 Same No<br />
CLOB CLOB Y* Character Character Same No<br />
CLOB CLOB Y* Open Open Same No<br />
DBCLOB DBCLOB Y* Graphic Graphic Same No<br />
DBCLOB DBCLOB Y* UCS2 UCS2 Same No<br />
136 <strong>File</strong> <strong>Management</strong> V4R5
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