Version 7.7.3
 —  Adabas Manager Documentation  —

Creating New LOB Files (Adabas for Mainframes Version 8 and Open Systems Only)

Large object fields (LB fields) are available with Adabas for mainframes version 8 and open systems. These are fields that may contain much more data than the 253 bytes of normal alphanumeric fields or the 16,381 bytes of LA fields. Fields containing large objects are defined with the new LB option. The theoretical maximum size of the value of an LB field is just short of 2 GB; practical usable sizes are smaller.

Adabas stores large object field values in a separate file, called a LOB file, that is tightly associated with the file containing the LB fields, which is called the base file. Behind the scenes, Adabas will store LB field values (except for very short ones) in the LOB file, but this is transparent to your application. Commands in application programs should always be directed against the base file; application programs need neither know nor care about the existence of a LOB file.

The New LOB File functionality of the Adabas Manager allows the creation of new LOB files.

Start of instruction setTo create a new LOB file for a database:

  1. Select an Adabas database in tree-view and expand it.

  2. Select Database Files in tree-view and right-click it.

  3. Select New LOB File on the drop-down menu.

    The Create LOB File panel appears in detail-view.

  4. Enter the following parameter values for the new file:

    Note:
    If you click Find next to the File Number text box, the next free file number will be displayed. If you enter a file number that already exists and click Find, the next free file number after the number you entered will be displayed.

  5. The following optional parameters can be set:

    Property Description
    ACRABN The address converter RABN space.
    DSRABN The data storage RABN space.
    NIRABN The normal index RABN space.
    UIRABN The upper index RABN space.
    ASSO Padding The padding factor (percentage of each block) set for the ASSO dataset (the default is 10).
    DATA Padding The padding factor (percentage of each block) set for the DATA dataset (the default is 10).
    Max. Blocks of DS Extents The number of blocks allowed per secondary Data Storage extent ("0" indicates that the parameter is not set; the default then is no limit).
    Max. Blocks of NI Extents The number of blocks allowed per secondary Associator normal index extent ("0" indicates that the parameter is not set; the default then is no limit).
    Max. Blocks of UI Extents The number of blocks allowed per secondary Associator upper index extent ("0" indicates that the parameter is not set; the default then is no limit).
    Data Device The device containing the Associator, Data Storage, or Work component.

    You can also set:

    Index Compression if the index for the file can be loaded in compressed form (the default depends on the input file).
    ISN Reuse if a freed ISN can be reused for a new record (the default is "NO").
    DS Reuse if Data Storage space can be reused (the default is "YES").
  6. Specify any parameters you may wish to set and click Finish to create the new LOB file.

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