Online CA Dataquery operates under CICS, where the online portion of the CA Dataquery system runs as a pseudo-conversational transaction, using CICS services to manage programs, storage, and terminal I/O. Online CA Dataquery also interfaces with several other CA products and facilities to complete processing of a user's query request. These include the CA Datacom Datadictionary Service Facility, the CA Datacom/DB Multi-User Facility (MUF), and the CA IPC CAIVPE.
DQL Mode Processing
To process a DQL Mode query, CA Dataquery first parses and edits the query. This involves using the CA Datacom Datadictionary Service Facility to validate key names, column names, and authorization data. This validation process also retrieves the information necessary to determine where and how to access the requested data.
Next CA Dataquery uses information retrieved from CA Datacom Datadictionary, such as TABLE-ID, DBID, and key name to formulate the appropriate CA Datacom/DB request to access the requested data. If CA Dataquery is running under CICS, this request is passed to CA Datacom CICS Services for staging. CA Datacom CICS Services controls CA Datacom/DB request traffic in the CICS region. The request is then passed to the CA Datacom/DB interface which controls traffic to the MUF. The request is then passed to the MUF for processing.
After processing is complete, the retrieved data is passed back through this same chain to CA Dataquery where further processing may take place.
Once CA Dataquery processing is complete, the results may be displayed in report format on the terminal or on a hardcopy printer. Query results may also be saved for later use.
DQL Mode Sort Processing
Sort processing varies, depending on the operating system:
If you have specified SORT, the sort routine reads the active found set from the DQF (Found Table). CA Dataquery attempts to sort the set in core. If there is not enough memory available, CA Dataquery issues a message and a return code, then attempts to sort the set within the Index Area for the CA Dataquery database. If the Index Area does not have enough space, CA Dataquery issues a message and terminates the query.
For batch, the process is the same except that CA Dataquery passes the set to the operating system sort routine. If the operating system sort routine cannot do the sort, CA Dataquery attempts the sort in the Index Area as it does for online. When sorting from DQBATCH, include the sort work JCL statements in your batch JCL, if needed.
SQL Mode Processing
For SQL Mode, CA Dataquery sends the entire query to CA Datacom/DB for validation and ORDER BY sorting. CA CA Datacom/DB uses CA Datacom Datadictionary to validate table and column names, and so forth, and determines where and how to access data. Next, CA Dataquery asks CA Datacom/DB to return the data. CA Datacom/DB passes the data back. Data can be sorted in SQL Mode only by an ORDER BY statement in the query. The rows are retrieved from CA Datacom/DB in sorted order. Reports are otherwise formatted by CA Dataquery.
Batch (DQBATCH)
CA Dataquery also operates in a batch mode (DQBATCH). Batch uses standard operating system services to manage programs, storage, and I/O. Processing is the same as described for online except that the CA Datacom CICS Services is not involved.
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