Tom Lane wrote: > Bruce Momjian <[EMAIL PROTECTED]> writes: > > No one has mentioned that we page value on disk to match the CPU > > alignment. This is done for efficiency, but is not strictly required. > > Well, it is unless you are willing to give up support of non-Intel CPUs; > most other popular chips are strict about alignment, and will fail an > attempt to do a nonaligned fetch. > > The only way we could pack stuff without alignment is to go over to the > idea that memory and disk representations are different --- where in > this case the "conversion" might just be a memcpy to a known-aligned > location. The performance costs of that seem pretty daunting, however, > especially when you reflect that simply stepping over a varlena field > would require memcpy'ing its length word to someplace.
Agreed, but I thought I would point it out. -- Bruce Momjian [EMAIL PROTECTED] EnterpriseDB http://www.enterprisedb.com + If your life is a hard drive, Christ can be your backup. + ---------------------------(end of broadcast)--------------------------- TIP 1: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to [EMAIL PROTECTED] so that your message can get through to the mailing list cleanly
