Mark Mielke wrote:
Kless wrote:The new data type, UUID, is stored as a string -char(16)-: struct pg_uuid_t { unsigned char data[UUID_LEN]; }; #define UUID_LEN 16What is the complaint? Do you have evidence that it would be noticeably faster as two 64-bits? Note that a UUID is broken into several non-64 bit elements, and managing it as bytes or 64-bit integers, or as a union with the bit-lengths specified, are probably all efficient or inefficient depending on the operation being performed. The hope should be that the optimizer will generate similar best code for each.
I didn't notice that he put 16. Now I'm looking at uuid.c in PostgreSQL 8.3.3 and I see that it does use 16, and the struct pg_uuid_t is length 16. I find myself confused now - why does PostgreSQL define UUID_LEN as 16?
I will investigate if I have time tonight. There MUST be some mistake or misunderstanding. 128-bit numbers should be stored as 8 bytes, not 16.
Cheers, mark -- Mark Mielke <[EMAIL PROTECTED]> -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
