[datafeed] make cnxset handling of datafeed source more robust
currently we may run in some cases where the session has no more cnxset
depending on errors and parser's handling of the cnxset.
Also, free the cnxset and reacquire it later, letting a chance to other
threads to run.
# -*- coding: utf-8 -*-
# copyright %(year)s %(author)s, all rights reserved.
# contact %(author-web-site)s -- mailto:%(author-email)s
#
%(long-license)s
"""%(distname)s precreate script, executed at instance creation time or when
the cube is added to an existing instance, before the schema is serialized.
This is typically to create groups referenced by the cube'schema.
"""