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White Paper:
InterPlex
Enterprise Gateway
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InterPlex SQL DDP UPDriver
InterPlex
SQL DDP UPDriver(s) is a collection of a main or driver program and some
number of subprograms that supply fast access queries and update
capabilities for InterPlex SQL. The
driver program(s) are generated through the InterPlex administration tool.
The driver portion directs the SQL requests to the appropriate
subprogram for DMS database access. The
subprograms are generated, based on a view that has been defined within
InterPlex SQL. For example, if you have a trivial subschema for schema ACCOUNTING,
and there exists three views called Receivable,
Payable, and Ledger, you would first define an UPDriver program.
Next you would define a subprogram for each accounting view and
finally, you would start the compile/map runstream.
All of these tasks are accomplished for you and there is no need
for any programming to create the InterPlex SQL DDP UPDriver processes.
The
benefit of the UPDriver program is a highly efficient method of fast query
with no programming necessary. This
subprogram must be generated when a view is to be used in an Insert,
Update, or Delete SQL statement or if the view is static and highly used. If the subprogram exists, any query or update type statement
will use the subprogram for access and update.
This subprogram was generated using the InterPlex SQL
administration tool and is specific to a single view.
Unlike the generalized access facility of InterPlex SQL, this
subprogram does not have to discover what access methods are available to satisfy the rows
of data. The discovery process, used by InterPlex SQL, involves imparting on
the internal DMS database and retrieving link and path information.
As discussed earlier, the link and path information is stored by
the schema/subschema analysis function or manually entered by the system
administrator. Once the
correct path is determined, a transaction is scheduled with the path
information supplied. Then
the target DMS database is imparted and data retrieval can begin.
So, by using the generated
subprogram, the query can bypass the discovery
process, thus enhancing performance as well as more efficiently
retrieving data.
The
UPDriver programs are DDP peers and must be registered with the Unisys DDP
CSUPDT process.
These programs can be run in batch or as transactions, depending on
the registration with DDP. If batch is chosen, the ECL run card can be set to various
batch priorities to enhance or tune the InterPlex SQL UPDriver executable.
When registered as a transaction, then you must have a valtab
entry, which allows the standard transaction settings, such as maximum
number of copies, TIP priority, and level values to be tuned.
InterPlex NET
InterPlex
NET listens for all inbound connection requests from an assortment of
InterPlex clients and servers. These
include, InterPlex APIs, InterPlex Enterprise gateways, and InterPlex ODBC
drivers. InterPlex NET is
responsible for enabling communications between two partners in a
distributed transaction. Specifically,
InterPlex NET enables clients and servers to connect to each other, send
data and responses, initiate interrupts, and disconnect when the session
is complete. During the life
of a connection, InterPlex NET resolves all differences between the
internal data representations and character sets of the computers being
used.
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UNISYS Integrators