Re: Why are data types size limited?

From: <joe_celko_at_my-deja.com>
Date: 2000/03/20
Message-ID: <8b4011$dvo$1_at_nnrp1.deja.com>#1/1


>> From an ignorant-user standpoint, they {SQL databases} are great
except for field size limitations ... Why is this? Why can't databases be written to handle arbitrarily long strings, and grow or shrink all input fields as needed? <<

That is actually a good question. When we were doing the SQL-86 and SQL-89 standards, we knew that SQL really stands for "Scarely Qualifies as a Language" -- a little ANSI humor.

The specs do not talk about internal representation of data types in the SQL database, only scale and precision, character sets, and other abstract things. The reason is that you never directly see SQL data!! The database exists in one place, the host program exists in another place and the SQL engine passes data back and forth between them, converting datatypes on the fly. This is why 'C' and Cobol can use the same database.

The datatypes we picked were the most universal, easiest to map to host programming languages we could imagine.

--CELKO-- Sent via Deja.com http://www.deja.com/
Before you buy. Received on Mon Mar 20 2000 - 00:00:00 CET

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