I find this Q & A a bit amusing:
http://www.sigmod.org/sigmod/record/issues/0506/p71-column-winslet.pdf
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Q. If you magically had enough extra time to do one additional thing at
work that you're not doing now, what would it be?
A. I think I would work on indexing a little harder.
Q. What aspect of indexing?
A. Oh, there are many aspects of indexing that I think need improvement.
I think we can do a better job in the searching. I think there are
exciting things to do in multi-dimensional indexing. I think there are a
lot more advanced ways that we can use database indexes for indexing on
columns that contain sequences or XML data, and for partial indexing.
With partial indexing, we would index only some of the rows, based on
some predicate. For example, we might not index the NULL values, or we
might index only those salaries greater than $100K.
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How long has a partial index implementation been in PostgreSQL? I seem
to recall it being brought up to speed around six years ago. The
underlying code may have been in there for much, much longer...
Mike Mascari
