> It is a minor thing, but if there is no other use for this fourth > "bit-space", it seems a shame to waste it when there is some use for it. I > haven't looked at the code around this area to know how hard it would be to > implement the setting and clearing of the bit.
I think so too, we would be able to use unused fourth status of bits efficiently. Should I include these improvement into this patch? This topic should be discussed on another thread after this feature is committed, I think.
The impossible state acts as a diagnostic check for us to ensure the bitmap is not itself corrupt.
-1 for using it for another purpose.
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Simon Riggs http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
