Re: Character string relation and functional dependencies
Date: Thu, 06 Dec 2007 14:38:48 -0800
Tegiri Nenashi wrote:
> On Dec 6, 9:40 am, rp..._at_pcwin518.campus.tue.nl (rpost) wrote:
>> Another difference is that database tables are finite and variable,
> Oh, relations in database world are certainly not restricted by finite
I thought that computers are finite, so the relations containable in them are too - even if damn large. There's a big difference between very large and infinite.
One ultimate limitation is the uniqueness requirement. Suppose you have a table with two integer columns. Since the range of the integer types are finite (even if your DBMS handles multi-precision integers), then the maximum number of distinct rows in the relation is also finite.
-- Jonathan Leffler #include <disclaimer.h> Email: jleffler_at_earthlink.net, jleffler_at_us.ibm.com Guardian of DBD::Informix v2007.0914 -- http://dbi.perl.org/ publictimestamp.org/ptb/PTB-1963 whirlpool 2007-12-06 21:00:03 7275FCF2EDF20725F56D081C5528272FCD717970FCEE5D43EDE454007D35AD3E246B5C FA6134D8AD5E2A60C6F43508ADFAE3E632D92807ED38395BFD14DA3EAReceived on Thu Dec 06 2007 - 23:38:48 CET