hash options - Mailing list pgsql-general

Hello,

I’m working on a data warehouse dimensionalization process   where I need to hash a text string to use as the key. 

I’ve implemented with MD5.  It works fine,  the problem I have is the size of the md5 (32 bytes) is often longer than the original string – thus not accomplishing what I want – space savings.

Does anybody have alternative hash function recommendations?  

 I looked at the options I knew of

select length(encode('ar=514','hex')); -- 12

select length(decode('ar=514','base64')); -- 24

select length(DIGEST('ar=514', 'md5')) -- 16bytes

select length(DIGEST('ar=514', 'sha1')) -- 20bytes

function is currently written in pg/plsql,  but I’m considering switching to python for broader library choice.

Source data is delimited list of name/value pairs.  Length range from 0-2500 bytes.

ar=514,cc=CA,ci=Montreal,cn=North+America,co=Sympatico,cs=Canada,nt=Xdsl,rc=QC,rs=Quebec,tp=High,tz=GMT%2D5

Thanks in advance

Doug Little

Sr. Data Warehouse Architect | Business Intelligence Architecture | Orbitz Worldwide

Douglas.Little@orbitz.com

   orbitz.com | ebookers.com | hotelclub.com | cheaptickets.com | ratestogo.com | asiahotels.com