Heikki Linnakangas wrote: > Zdenek Kotala wrote: > > 4) Implementation > > > > The main point of implementation is to have several version of > > PageHeader structure (e.g. PageHeader_04, PageHeader_03 ...) and correct > > structure will be handled in special branch (see examples). > > (this won't come as a surprise as we talked about this in PGCon, but) I > think we should rather convert the page structure to new format in > ReadBuffer the first time a page is read in. That would keep the changes > a lot more isolated. > > Note that you need to handle not only page header changes, but changes > to internal representations of different data types, and changes like > varvarlen and combocid. Those are things that have happened in the past; > in the future, I'm foreseeing changes to the toast header, for example, > as there's been a lot of ideas related to toast options compression.
I understand the goal of having good modularity (not having ReadBuffer modify the page), but I am worried that doing multi-version page processing in a modular way is going to spread version-specific information all over the backend code, making is harder to understand. -- Bruce Momjian <[EMAIL PROTECTED]> http://momjian.us EnterpriseDB http://enterprisedb.com + If your life is a hard drive, Christ can be your backup. + -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
