[elephant-devel] migration

[Alex Mizrahi]

hi

i've promised to fix some bugs in db-postmodern and make it ready for 1.0 
"soon", but unfortunately those issues were much more serious than i thought 
(i found some more bugs), and that required considerable changes. but 
finally it seems to be done, now i'm doing tests and making patches.

meanwhile, i was going to test upgrade path from 0.9.1 via migration -- my 
idea
is that you can migrate from postmodern store to bdb, then upgrade bdb store 
from 0.9.1 to 1.0, then migrate it back from bdb to postmodern. but running 
migration tests in 0.9.1, it seems to be broken -- map-cache was broken, and 
it complained about null *store-controller* in find-inverted-index.
i'm not sure if that's a problem of tests or actual problem of migration..

so, my questions are:
 * does anybody know anything about state of migration in 0.9.1, does it 
work? does it make sense to fix it?
 * do anybody actually need this path of migration of postmodern from 0.9.1 
to 1.0, or i'm just wasting my time?

there is alternative path of upgrade -- via gp-export. i suspect that 
gp-export
might not work in some cases like when you store data directly in btrees 
rather than in objects,
but it works for me, at least.

also, there is a question about upgrade from elephant-unstable to 
elephant-1.0 -- i've made some small change that makes stores incompatible. 
would anybody regret about this?