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.
To create a new LOB file for a database:
Select an Adabas database in tree-view and expand it.
Select Database Files in tree-view and right-click it.
Select on the drop-down menu.
The Create LOB File panel appears in detail-view.
Enter the following parameter values for the new file:
File Number
File Name (optional )
Base File (the file containing the large object (LB) fields)
MAXISN
Data Storage Size
Normal Index Size
Upper Index Size
Note:
If you click 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
, the next free file number after the number you
entered will be displayed.
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"). |
Specify any parameters you may wish to set and click to create the new LOB file.
