Re: Values larger than 1/3 of a buffer page cannot be indexed.

Brian Hirt wrote:
> On Mar 13, 2011, at 12:05 PM, Dmitriy Igrishin wrote:
>
>> Hey Viktor,
>>
>> 2011/3/13 Viktor Nagy <viktor(dot)nagy(at)toolpart(dot)hu
>> <mailto:viktor(dot)nagy(at)toolpart(dot)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

Unless the point is to guarantee uniqueness of the "long-long value"s.