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Just for discussion, here are two *hypothetical* database systems with a listing of corresponding datatypes. (no they are real but let's not get into the vendors). Both of these can issue and accept XML. Without a way to spec datatypes, just how good are my chances that the db will handle the data not as I see fit, but such that regardless of the db, I or anyone that uses the XML, will get the same results. Doesn't this become an issue for anyone who tries to spec a common XML document type for say, ebXML? Are elements and attribute names sufficient? Today, we have to write a lot of code to handle this. I don't think that is a good solution for interop. len *************************************************************************** Fixed Length String System 1: CHAR(n)- limit 2KB System 2: CHAR(n), CHARACTER(n)- limit 255 (6.5)- limit 8KB (7.0) Variable Length String System 1: VARCHAR2(n), VARCHAR(n)- limit 4KB in a column- limit 32KB in a variable- VARCHAR is obsolete System 2: VARCHAR(n), CHAR VARYING(n), CHARACTER VARYING(n)- limit 255 (6.5)- limit 8KB (7.0) Integer System 1: INTEGER, INTEGER(n), SMALLINT System 2: INTEGER (4 bytes), INT (4 bytes), SMALLINT (2 bytes), TINYINT (1 byte), BIT (1 bit) Fixed Point System 1: NUMBER, NUMBER(n), NUMBER(n,d),FLOAT, FLOAT(n), FLOAT(n,d) System 2: NUMERIC, NUMERIC(n), NUMERIC(n,d),DECIMAL, DECIMAL(n), DECIMAL(n,d),DEC, DEC(n), DEC(n,d),MONEY, SMALLMONEY Floating Point System 1: DECIMAL System 2: FLOAT, FLOAT(n), DOUBLE PRECISION, REAL, Date System 1: DATE System 2: DATETIME, SMALLDATETIME, TIMESTAMP- TIMESTAMP auto-updated Binary System 1: RAW(n)- limit 255 bytes System 2: BINARY(n), VARBINARY(n), BINARY VARYING(n)- limit 255 (6.5)- limit 8KB (7.0) Large String System 1: LONG, LONG VARCHAR- limit 2GB- limit one per table rowCLOB- limit 4GB System 2: TEXT- limit 2GB Large Binary System 1: LONG RAW- limit 2GB- limit one per table rowBLOB- limit 4GB System 2: IMAGE- limit 2GB Multi-byte chars System 1: NCHAR(n)NVARCHAR(n)NCLOB- same limits as CHAR, VARCHAR, CLOB System 2: NCHAR(n), NATIONAL CHAR(n), NATIONAL CHARACTER(n)NVARCHAR(n), NATIONAL CHAR VARYING(n), NATIONAL CHARACTER VARYING(n)NTEXT, NATIONAL TEXT- same limits as CHAR, VARCHAR, TEXT Row Identifier System 1: implicit ROWID column System 2: (use an IDENTITY column) Secure OS Label System 1: MLSLABEL, RAW MLSLABEL System 2: <not supported> 128-bit Unique Number(UUID, GUID) System 1: <not supported> System 2: UNIQUEIDENTIFIER (version 7.0 only) From: Jonathan Robie [mailto:jonathan.robie@d...] I don't know how to design a language that will avoid any possible philosophical or aesthetic objections on XML-Dev. I'm an engineer, not a deity. But if you give me a concrete problem to solve, I think we have a Working Group that might be able to solve it.
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