On Sun, Mar 13, 2011 at 4:37 PM, Rob Sargent <robjsargent@xxxxxxxxx> wrote: > > > Brian Hirt wrote: >> >> On Mar 13, 2011, at 12:05 PM, Dmitriy Igrishin wrote: >> >>> Hey Viktor, >>> >>> 2011/3/13 Viktor Nagy <viktor.nagy@xxxxxxxxxxx >>> <mailto:viktor.nagy@xxxxxxxxxxx>> >>> >>> hi, >>> >>> when trying to insert a long-long value, I get the following error: >>> >>> index row size 3120 exceeds maximum 2712 for index >>> "ir_translation_ltns" >>> HINT: Values larger than 1/3 of a buffer page cannot be indexed. >>> Consider a function index of an MD5 hash of the value, or use >>> full text indexing. >>> >>> is there a way to generate this recommended function index of an >>> md5 hash on an already existing database and tables (filled with >>> data)? >>> >>> Just create index this way, e.g. >>> CREATE INDEX ir_translation_ltns ON tab ((md5(col))); >>> where "tab" and "col" are table and column of which you want >>> to create btree index. >> >> This probably goes without saying, but you'll have to use col = >> md5('blahblahblahblah') in your qualifiers to get the benefit of the index. >> >> --brian > > Unless the point is to guarantee uniqueness of the "long-long value"s. md5 will do that too: the main thing you lose going to hash indexing is ordering. merlin -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
