Copyright © TIBCO Software Inc. All Rights Reserved
Copyright © TIBCO Software Inc. All Rights Reserved


Chapter 3 Managing IMS Data Definitions : Defining Secondary Indexes

Defining Secondary Indexes
You can define up to five fields of any syntax as secondary index fields for an IMS table definition. Consider the following when defining secondary indexes on IMS fields:
Index fields can be selected only as S, K, V, or P fields; however, only base index fields can have access values (V).
If you toggle from Base Index field to sub index fields (pressing PF6), all sub index fields are automatically selected. It is a Gateway requirement that all sub index fields are included.
Defining Access Values
You can access a subset of segment occurrences by supplying a value for one or more IMS fields. This restricts which segment occurrences are returned to TIBCO Object Service Broker. The value (specified in upper or lowercase) is used to search the database with an equality condition. For example, you could choose to return all occurrences where CUSTNAME = Smith.
To define an access value, use the following procedure.
1.
On the IMS Field Selection screen shown in the Task G: Select IMS Fields, type V beside the IMS field or fields for which you want to specify an access value and press Enter.
2.
If you selected more than one field, the Access Value screen is refreshed when you press PF3 or PF12, and you can specify the value for the next selected field.
3.
To remove an access value, blank out the value in the Access Value screen or type D beside the field you are modifying and press Enter.
4.
Fields with access values are not automatically selected as fields of the IMS table. To select an access value field as a field of the table, type an S beside it and press Enter.
Fields containing access values are identified with a Y in the Val field on the IMS Field Selection screen.
Sample Access Value Screen

 
Enter the access value for CUSTNAME
 
 
PFKEYS: 3=END 12=CANCEL

 
Defining Multiple Record Formats
You define segments with more than one record format to TIBCO Object Service Broker by supplying access values. When an IMS segment contains a different number of fields depending on the value of another field within the segment, you must create one IMS table definition for each access value you require.
For example, the table below illustrates DEFN1 and DEFN2 using different access values to define RECTYPE = 1, where the segment contains three numeric fields, and RECTYPE = 2, where the segment contains two character fields.
Defining Multiple Record Formats to TIBCO Object Service Broker
 
Mapping Data Types
The table below displays default mapping of IMS data types from the DBD to TIBCO Object Service Broker semantic types and syntax. Valid TIBCO Object Service Broker semantic types and syntax are described in TIBCO Object Service Broker Programming in Rules.
IMS to TIBCO Object Service Broker Default Data Mapping
 
TIBCO Object Service Broker Semantic Type
TIBCO Object Service Broker Syntax
TIBCO Object Service Broker Length
3 (for Binary 2) 5 (for Binary 4)
IMS Data Translation
This table displays the valid TIBCO Object Service Broker syntax and length to use when defining new fields or modifying the default syntax and length of existing fields. Valid TIBCO Object Service Broker semantic types are described in TIBCO Object Service Broker Programming in Rules.
IMS Length
TIBCO Object Service Broker Syntax
TIBCO Object Service Broker Length
Packed, neutral - (X'0F') sign when positive (X'0D') sign when negative

1
You must specify the appropriate number of decimal places, if necessary.

2
The hexadecimal value of data appears. For example, a two-byte field (X'C1C2') appears in a four-byte variable-length TIBCO Object Service Broker field (C1C2).

3
The remainder of a variable length character field is padded with binary zeros, instead of blanks.

Note: The date (D) semantic type is not valid for IMS tables.

Copyright © TIBCO Software Inc. All Rights Reserved
Copyright © TIBCO Software Inc. All Rights Reserved