Re: Changing the function used in an index. - Mailing list pgsql-general

From David Johnston
Subject Re: Changing the function used in an index.
Date
Msg-id 1373634000020-5763582.post@n5.nabble.com
Whole thread Raw
In response to Changing the function used in an index.  (Clodoaldo Neto <clodoaldo.pinto.neto@gmail.com>)
List pgsql-general
Clodoaldo Neto wrote
> How does the planner know that the function used in an index has changed?
> If the function's body is changed keeping the argument and return types
> the
> planner will not use it anymore:

Not a hacker but the function catalog entry is MVCC just like any other
record and so even if you alter the function without changing the signature
the system still knows that something has changed.  Since the system cannot
inspect the function change to know whether the original and new function
provide the same output given the same input it can no longer trust the
index.  For me the "how" doesn't matter and it is working as expected.

Do you have some larger intent than just understanding how that you have not
made clear?

David J.





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