Re: pg_upgrade: error when migrating from 8.3 to 9.1

sayeed <sayeed(dot)anjum(at)gmail(dot)com> writes:
> I am trying to upgrade a database from postgresql 8.3.8 to 9.1. (Ubuntu 10.10
> Maverick)
> It is crashing out with the following error:
> psql:/var/lib/postgresql/pg_upgrade_dump_db.sql:85146: ERROR: could not
> find function "pg_freespacemap_pages" in file
> "/usr/lib/postgresql/9.1/lib/pg_freespacemap.so"

> Why does this happen?

Because pg_freespacemap_pages() doesn't exist (and neither does the
freespace map) in versions after 8.3. Had pg_upgrade existed at the
time we removed the FSM, we might have taken a bit more care with what
would happen in an upgrade situation ... but it didn't.

You could do this via pg_dump and reload, in which case the missing
functions would result in ignorable errors during the reload.
If you want to do it via pg_upgrade, I think the most practical way
is to drop the whole pg_freespacemap extension (ie, run its uninstall
script) in your 8.3 installation, then do the upgrade, then install
9.1's version of the extension if you still want it.

regards, tom lane