On Sun, 2002-09-29 at 19:28, Tom Lane wrote: > Hannu Krosing <[EMAIL PROTECTED]> writes: > > The initial Postgres design had a notion of StorageManager's, which > > should make this very easy indeed, if it had been kept working . > > But the storage manager interface was never built to hide issues like > tuple representation --- storage managers just deal in raw pages.
I had an impression that SM was meant to be a little higher-level. IIRC the original Berkeley Postgres had at one point a storage manager for write-once storage on CDWr jukeboxes. the README in src/backend/storage/smgr still contains mentions about Sony jukebox drivers. http://www.ndim.edrc.cmu.edu/postgres95/www/pglite1.html also claims this: Version 3 appeared in 1991 and added support for multiple storage managers, an improved query executor and a rewritten rewrite rule system. For the most part, releases since then have focused on portability and reliability. > I doubt it would have helped in the least for anything we've been > concerned about. Yes, it seems that we do not have a SM in the semse I hoped. Still, if we could use a clean SM interface over old page format, then the tuple conversion could be done there. That of course would need the storage manager to be aware of old/new tuple structures ;( ----------------- Hannu ---------------------------(end of broadcast)--------------------------- TIP 5: Have you checked our extensive FAQ? http://www.postgresql.org/users-lounge/docs/faq.html
