Overview of lns databases, Automatic database upgrade – Echelon LNS User Manual
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LNS Programmer's Guide
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Overview of LNS Databases
As described in Chapter 3, the LNS Server maintains two types of databases: the LNS
global database and a set of LNS network databases. These are high-performance disk-
based databases with in-memory caching to optimize repeated access to data.
The LNS global database contains the Networks collection, meaning that it contains the
names and locations of each of the network databases. The location of the global database
is maintained in the Windows Registry, and can be accessed using the
DatabasePath
property of the ObjectServer object. This is set to the ObjectServer\GlobalDb
subfolder of the L
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folder by default. A backup, empty copy of the global
database is available in the ObjectServer\BackupDb folder. The location of the global
database should be set when LNS is installed and then never changed, as LNS
applications must access the same global database if they are to interoperate.
Each network defined in the global database and managed by the LNS Server has its
own network database. The network database contains the network and device
configuration information for that specific L
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network. This chapter provides
guidelines you should follow to maintain your LNS databases. This includes the following
topics:
• Backing Up Network Databases
• Validating Network Databases
Automatic Database Upgrade
If you are upgrading to LNS Turbo Edition from a previous version of LNS, you do not
need to worry about compatibility issues between your LNS databases and the software
installed with LNS Turbo Edition. All LNS databases since Release 1.0 are compatible
with LNS Turbo Edition, and are automatically upgraded when they are opened by an
application running on LNS Turbo Edition.
This conversion is a multi-step process that could take a significant amount of time, as
global database and all the network databases must all be upgraded when they are first
opened with an LNS application that is running on LNS Turbo Edition. You can use the
OnDbConversionEvent event to track the progress of this procedure. This event is
triggered once for each stage of the conversion, and once when the conversion is
complete. See the LNS Object Server Reference help file for more information on the
OnDbConversionEvent event.
NOTE: LNS databases are not backward compatible. Once a database is upgraded, the
upgrade changes cannot be reversed, and the database cannot be accessed using pre-
Turbo Edition versions of LNS.