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


Chapter 4 Processing IMS Data : Accessing TIBCO Object Service Broker IMS Tables

Accessing TIBCO Object Service Broker IMS Tables
When accessing IMS data from TIBCO Object Service Broker, TIBCO Object Service Broker requests are translated into Segment Search Arguments (SSAs), which are used in a DL/I call to IMS. SSAs are built based on parameterized fields, access values, and the selection criteria specified for primary keys and any field defined in the DBD. The DBD used when data is accessed must be identical to the DBD used when the TIBCO Object Service Broker IMS table is defined.
IMS field data types are translated to the TIBCO Object Service Broker field types defined in the IMS table.
You can access the data using:
Using the Table Browser and Table Editor
You can browse and edit an IMS table in the same way you would browse or edit any other TIBCO Object Service Broker table with the following exceptions:
Optimize Update=Y
If Optimize Update=Y, you cannot update or order the segment occurrences of the table.
Modifying Primary Key Values
If you modify the value of the primary key of a table in the Table Editor, a DELETE followed by an INSERT is issued on your behalf. If the segment the primary key is defined at is a parent, all child segments associated with that parent are deleted. Only the child segment occurrence displayed in the Table Editor is inserted back into the database.
Field of Syntax C or V Longer than 260 Bytes
If your table definition contains fields of syntax C or V that are longer than 260 bytes:
You must use SELECT LIKE instead of SELECT to access fields of this length.
Using the Single Occurrence Editor
Using the Single Occurrence Editor from the Table Browser begins a dependent transaction in TIBCO Object Service Broker, assigning a new Gateway. Therefore, to use the Single Occurrence Editor from the Table Browser, you must have one of the following running with the same SERVERID:
However, you can use the Single Occurrence Editor from the Table Editor without this condition, since this does not begin a dependent TIBCO Object Service Broker transaction.
The Table Browser does not hold locks on TDS data; however, this is not true for IMS tables. Locking of IMS data is determined by the PROCOPT parameter for the database PCB in the Gateway PSB. Refer to Defining Gateway Program Specification Blocks.
Unique Sequence Keys of Child Segments
If you include the unique sequence key of a child segment as a field of an IMS table (instead of a parameter, access value, or primary key) and you modify the value of this field the following occurs:
The Gateway attempts to retrieve the segment occurrence with a Get Hold Unique (GHU) using the unique sequence key of both the parent and the modified child segment.
If the newly specified combination of unique sequence keys exists, the entire segment occurrence is replaced with the data displayed in the Table Editor or the Single Occurrence Editor. Be careful that the replaced segment occurrence is the occurrence you intended to update.
If the newly specified combination of unique sequence keys does not exist, an error message is issued stating that the update failed because the occurrence could not be found.
You can be sure only that the proper replacement occurs if unique sequence keys of child segments are identified as key fields to TIBCO Object Service Broker.
Browsing IMS Tables
You can use the Table Browser to browse a defined IMS table by typing a table name next to the BR browse table option, for example:
CUST_ORDERS<Enter>
The sample screen below shows IMS data presented in TIBCO Object Service Broker table format. The IMS table is named CUST_ORDERS and the parameter values for CUSTNO and ORDER# are both 000001.
Browsing an IMS Table

 
BROWSING TABLE : CUST_ORDERS(000001,000001)
COMMAND ==>
SCROLL: P
PRODUCT# QUANTITY
_ ------ ----------
_ 000001 99
_ 000002 999
_ 000003 10
_ 000004 10
PFKEYS: 1=HELP 5=FIND NEXT 9=RECALL 18=EXCLUDE 13=PRINT 3=END 14=EXPAND
At TOP

 
See Also
TIBCO Object Service Broker Managing Data for more information on browsing tables.

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