External data references

You can also use PI AF tables to access data that is external to the PI System. Such data might be contained in Microsoft Excel, Access, or SQL Server, or other OLE DB/ODBC data sources. You can either import the table or link to it after you have defined the table structure, as described in Create PI AF tables and Create table column definitions.

Imported tables

PI AF tables with imported data are called imported tables. Imported tables are read/write tables. They are limited in size but are more secure than linked tables. Imported tables are sometimes called internal tables because, unlike linked tables, the table data is managed in PI AF. After the initial import, there is no further relationship between the foreign table and the PI AF table. You can edit the data directly in PI AF.

It is a good practice to limit your imported tables to 10,000 rows of data or less. Imported tables are not designed for storing very large databases. If you need to access a lot of data in PI AF tables, link to external tables instead, which do not present such storage limits. Alternatively, break the table into separate tables when importing.

Linked tables

Linked tables are sometimes called external tables, because the source data is not stored in the PI AF database. You cannot edit an external table from PI AF. Linked tables require additional security configuration because you need to configure how PI AF connects to the external data source. You should set up a reusable table connection, where you configure the type of authentication to access the external table.

Videos

For information on how to import data from external tables, watch this video:

For information on how to link to data in external tables, as well as SQL security, watch this video: