On Thursday 21 May 2009 11:06:29 Dmitry Koterov wrote: > 1. Store the DEFAULT flag directly in NULL BITMAP (add a bit to NULL bitmap > not only for NULLable fields, but also for NOT NULL DEFAULT ... fields). > 2. Add another bitmap for each tuple (DEFAULT bitmap). Bit value 0 means > that there is a real value in a cell, 1 - that the value is default. > 3. The same as (1), but always force default value to be 0 (or false or any > other values with meaning "zero") and optimize only these cases.
It seems to me that these solutions would require everyone in the world to pay the overhead of a few to many bits in every tuple to optimize what appears to be a relatively rare circumstance after all. Doesn't seem worth it to me. -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
