On Mar 13, 2011, at 12:05 PM, Dmitriy Igrishin wrote:
Hey Viktor,
2011/3/13 Viktor Nagy
<viktor.nagy@toolpart.hu> 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