On Sun, Oct 1, 2023 at 05:30:39AM -0400, Ann Harrison wrote: > Other databases do allow that sort of gradual migration. One example > has an internal table of record descriptions indexed the table identifier > and a description number. Each record includes a header with various > useful bits including its description number. When reading a record, > the system notes the description number and looks up the description > before parsing the record into columns. > > The transition is made easier if the database indexes are generic - > for example, numbers rather than decimal[12,6], int32, etc., and string > rather than varchar[12]. That way, increasing a column size doesn't > require re-indexing. > > But, those are decision that really had to be made early - making > a major format change 25+ years in would break too much.
And the performance sounds terrible. ;-) -- Bruce Momjian <br...@momjian.us> https://momjian.us EDB https://enterprisedb.com Only you can decide what is important to you.
