LOBs with DB2 for z/OS: Stronger and Faster

96 LOBs with DB2 for z/OS: Stronger and Faster

Explanations of Example 4-11 on page 95 are:

򐂰 filename: Contains the name of the IXF input file that contains the data to be loaded (data

of the base table columns and the names of the LOB files). If the path is omitted, the

current working directory is used.

򐂰 IXF: File format of the input file supported by DB2 on the host (IXF is integrated exchange

format, in which most of the table attributes are saved).

򐂰 lobpath: Specifies the path where the LOB files are stored. The names of the LOB data

files are stored in the main input file in the column that is loaded into the LOB column.

򐂰 into: Specifies the host table or host view to be loaded.

The best way to create a working base for the IMPORT command is to first EXPORT a similar

table from the host to the workstation using an EXPORT command as shown in

Example 4-12. Similarly, you first have to CONNECT to the host DB2 system.

Example 4-12 EXPORT command

export to filename of ixf lobs to lobpath lobfile lobfile modified by

lobsinsepfiles select * from X.MYTABLE

The explanations for Example 4-12 are:

򐂰 filename: Contains the name of the IXF file to which data is to be exported. If the

complete path to the file is not specified, the export utility uses the current directory and

the default drive as the destination.

򐂰 lobpath: Specifies a path to a directory in which the LOB files are to be stored.

򐂰 lobfile: Contains the base file name for the LOB files. When creating LOB files during an

export operation, file names are constructed by appending the current base name from

this list to the current path from lobpath and then appending a 3-digit sequence number.

For example, if the current LOB path is the directory c:\u\davy\lobpath, the LOB files

created are c:\u\davy\lobpath\lobfile.001.lob, c:\u\davy\lobpath\lobfile.002.lob, and so

forth.

򐂰 lobsinsepfiles: Required parameter to specify that the LOBs are stored in separate files on

the lobpath.

򐂰 From: Specifies a host table or host view containing the columns to unload from the host.

Afterwards, you can create a similar IXF file on the workstation and edit it with the names of

the LOB files you want to upload.

See the DB2 for Linux, UNIX and Windows manuals for complete information about the

IMPORT and EXPORT commands.

4.5 Locking

Locking for LOBs has significantly changed in DB2 9; therefore, the information about LOB’s

locking techniques with DB2 V8 and DB2 9 are mentioned in two separate sections.

For LOB locking with DB2 V8, see 4.5.1, “Locking for LOBs with DB2 V8” on page 97. Locking

for LOBs beginning with DB2 9 is described at 4.5.2, “Locking for LOBs with DB2 9” on

page 103. Note that the different locking mechanisms introduced in DB2 9 were not retrofitted

to DB2 V8.

Tip: Be sure that the input file does not contain values for the ROWID column. These are

rejected by DB2 on the host when the ROWID column was defined there as GENERATED

BY DEFAULT.