dhis2-devs team mailing list archive

[Bob Jolliffe <bobjolliffe@xxxxxxxxx>]

I had a go at this earlier with reasonable success.  You have to make
an uncompressed pg dump with insert statements (these are both
optional parametrs to pg_dump).  Some very slight adjustment to the
structural metadata - I'll document later if people are interested -
and then tried to import data.

Only one snag - pg has its own peculiar way of handling binary strings
(bytea fields) which h2 doesn't emulate.  Can't blame h2 too much -
what pg does is a bid weird.

This affects systemsettings, usersettings and reportsettings.

Other than that I imported 1.5 million datavalues and associated
dataelements, orgunits etc.

The h2 guys are aware of the bytea compatibility problem and have the
issue roadmapped - apparently they will bump it if it something people
request.  I guess I should request.

If I was really pushed I could write a script to find all the binary
strings in the pg dump and try to convert them to something h2 is
happy with.

Having said that, I think all the places where we currently use binary
strings are really unnecessary (storing evil java serialized objects)
which I think have a historical rationale.  It should be relatively
easy and desirable to change these - particularly as we also want to
represent these things in xml - but we'd have to consider the effect
on compatibility with legacy dhis databases which have the blobs.  I
guess we'd need an upgrade script of some sort.

So the prognosis is good but not quite seamless yet.

Cheers
Bob

BTW how did you make the demo db?

2010/4/12 Lars Helge Øverland <larshelge@xxxxxxxxx>:
>
>
> I see H2 can be run in "PostgreSQL mode" by appending ;MODE=PostgreSQL to
> the connection URL:
> http://www.h2database.com/html/features.html#compatibility
>
> Could be interesting to try to import the pgdump using this..
> Lars
>