+ <column name="db_version">
+ <p>
+ The database schema version number in the form
+ <code><var>major</var>.<var>minor</var>.<var>tweak</var></code>,
+ e.g. <code>1.2.3</code>. Whenever the database schema is changed in
+ a non-backward compatible way (e.g. deleting a column or a table),
+ <var>major</var> is incremented. When the database schema is changed
+ in a backward compatible way (e.g. adding a new column),
+ <var>minor</var> is incremented. When the database schema is changed
+ cosmetically (e.g. reindenting its syntax), <var>tweak</var> is
+ incremented.
+ </p>
+
+ <p>
+ The schema version is part of the database schema, so it can also be
+ retrieved by fetching the schema using the Open vSwitch database
+ protocol.
+ </p>
+ </column>
+