|DB2 UDB now makes use of LOB location specifiers (LLSs) when importing, |exporting, and loading large object (LOB) information. This allows |multiple LOBs to be stored in a single file.
|An LLS is a string indicating where LOB data can be found within a |file. The format of the LLS is |filename.ext.nnn.mmm/, where |filename.ext is the name of the file that contains the LOB, |nnn is the offset of the LOB within the file (measured in bytes), and |mmm is the length of the LOB (in bytes). For example, an LLS |of db2exp.001.123.456/ indicates that the lob |is located in file db2exp.001, begins at an offset of 123 |bytes into the file, and is 456 bytes long. If the indicated size in |the LLS is 0, the LOB is considered to have a length of 0. If the |length is -1, the LOB is considered to be NULL and the file name and offset do |not matter.
|When exporting data using the lobsinfile modifier, the LOBs will |not always be placed into separate files. There may be multiple LOBs in |each LOB file, and multiple LOB files per LOB path. The data file will |now contain LLS records instead of just file names.
|The import and load functions have also been changed to handle the changes |to the export function. When loading or importing data with the |modified by lobsinfile option specified, LLSs will be expected for |each of the corresponding LOB columns. If something other than an LLS |is encountered for a LOB column, the database will treat it as a LOB file, and |will load the entire file as the LOB.
|There are three new IXF data types. These three types correspond to |character large objects (CLOBs), binary large objects (BLOBs), and double-byte |character large objects (DBCLOBs) when represented by LLSs. The values |of these data types are 964, 960, and 968 respectively.
|IXF files now require each LOB column to have its own D record. This |is created automatically by the export tool, but must be created manually if |you are using a third party utility to create the IXF files. |Additionally, an LLS is required for each LOB in the table, and not just the |non-null LOBs. If a LOB column is null, you must write an LLS |representing a null LOB.