Florian Pflug <f...@phlo.org> writes: > On Dec1, 2010, at 17:17 , Tom Lane wrote: >> There's not enough space in the infomask to record which columns (or >> which unique index) are involved. And if you're talking about data that >> could remain on disk long after the unique index is gone, that's not >> going to be good enough.
> We'd distinguish two cases > A) The set of locked columns is a subset of the set of columns mentioned in > *any* unique index. (In other words, for every locked column there is a > unique index which includes that column, though not necessarily one index > which includes them all) > B) The set of locked columns does not satisfy (A) How's that fix it? The on-disk flags are still falsifiable by subsequent index changes. > Creating indices shouldn't pose a problem, since it would only enlarge the > set of locked columns for rows with HEAP_XMAX_SHARED_LOCK_KEY set. Not with that definition. I could create a unique index that doesn't contain some column that every previous unique index contained. regards, tom lane -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers