more issues to discuss in Tallahassee

[Arie Shoshani <arie@math.lbl.gov>]

Here are a few more items (in addition to the 4 I sent previously)
that we think need to be discussed at the Tallahassee meeting.  I
think a couple of the points partially overlap Dave's points, but to
be sure I added them anyway.

Doug, you can just add these to the previous list.

Arie.
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5.  User ID 

One of the tasks of the Caching Policy module is to make sure that the
system is not abused by a single user.  Thus, if a query is issued and
multiple event-iterators (EIs) are created on its behalf, then as long as
each EI has the query-ID assoicated with it, the Caching Policy module
knows to allocate resources limited to a single query.  However, we
have no way of preventing a user from breaking up a query into
multiple queries to get more resources.  Do we need to associate a
user-ID with each query as well?

6.  Event "vertical" partitioning

It is a requirement that events will be partitioned into multiple
parts: tag data (summary data), track data, vertex data, raw data,
and perhaps other.  Each of these partitions will be stored and
indexed separately.  How does this effect the file organization, the
clustering, the indexes, the query language, etc.?  How would this be
managed through Objectivity?

7.  External cache

What is the cache that Objectivity will use at the MDC?  Assuming that
Objectivity will not have an HPSS connection in place by then, it will
have to use a cache external to HPSS.  Which module will move files
loaded into Objectivity into HPSS?  Will the cache manager move files
from HPSS tapes directly to the external cache in this case?

8.  Dynamic clustering

This is beyond the MDC, but we need to discuss dynamic clustering,
i.e. putting events into different files (containers) dynamically
according to pre-specified properties.  What is the effect on file
placement on tape?  What is the effect on the indexes (can they grow
dynamically)?  What is the effect on re-structuring?