Re: WIP: extensible enums

Tom Lane <tgl@sss.pgh.pa.us>

From: Tom Lane <tgl@sss.pgh.pa.us>
To: Dean Rasheed <dean.a.rasheed@gmail.com>
Cc: Andrew Dunstan <andrew@dunslane.net>, Robert Haas <robertmhaas@gmail.com>, pgsql-hackers@postgresql.org
Date: 2010-10-18T17:48:45Z
Lists: pgsql-hackers
Dean Rasheed <dean.a.rasheed@gmail.com> writes:
> I think the hash map lookups could be made pretty quick, if we're
> prepared to write a bit of dedicated code there rather than relying on
> the more general-purpose caching code.

It's still going to be very significantly slower than what I'm
suggesting --- I'm *already* assuming that step 4 is using a hash
or something else smarter than just traversing a list.  My step 3
is just a bit-array index operation (well, 2 of 'em).

(I'm pretty dubious of unsubstantiated claims that you can build a hash
table that's significantly faster than our existing hash code, anyway.)

			regards, tom lane