● Representation of the message archives
● Querying the message archive
6.7.2 Basics of OLE DB
Introduction
You can access process value and message archives using the OLE DB interface made
available by the PCS 7 OS and the corresponding database provider.
OLE DB
OLE DB is an open standard for fast access to different databases. It is irrelevant whether or
not the database is relational. The connection between the OLE DB level and the database is
established by an OLE DB provider. OLE DB interfaces and providers are available from
various vendors.
WinCC OLE DB provider
With the WinCC OLE DB provider, you have direct access to PCS 7 OS archive data stored
in the MS SQL server database. Depending on the configuration, process data of the PCS 7
OS is stored in compressed form.
The differences to Microsoft OLE DB provider are shown in the following table:
WinCC OLE DB provider Microsoft OLE DB-Provider
Transparent access to the
process data of the PCS 7 OS
possible Not supported
Read data via multiple database
segments
possible Not supported
Note
When the OS server closes a full archive and opens a new archive, there is a brief time when
no data is read from the message and process value archives via the WinCC OLE DB provider.
Microsoft OLE DB
The Microsoft OLE DB provider is the database provider of Microsoft. This can be implemented
with database access to the MS SQL Server database.
OpenPCS 7 interface
6.7 OLE DB
OpenPCS 7
Function Manual, 05/2012, A5E02780178-02 81
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