With my server migration I switched from
PostgreSQL 8.2 to 8.3. However, I've installed
MediaWiki for the
awesome wiki on 8.2, but dumping from 8.2 and restoring to 8.3 just failed because of the tsearch2 extension, which is now part of PostgreSQL 8.3.
With the help of my friend
Dimitri, the
pgloader author, I managed to migrate the database from PostgreSQL 8.2 to 8.3. Here is how I did.
This was done with MediaWiki 1.12, and I doubt that
older version supports PostgreSQL 8.3.
Dump the database schema
First, you need to dump the database schema, and then, the database data. We need to do it in two steps because we need to change the schema a bit. I assume that MediaWiki is installed in the
mediawiki schema:
% pg_dump -s -n mediawiki wikidb > wikidb-schema.sql
Convert the schema
Then, edit your
wikidb-schema.sql. When you installed
tsearch2, you probably did it in the
public schema like I did. So it created two or three data types used by MediaWiki wich are named
public.datatype. These
tsearch2 datatypes are now part of PostgreSQL, so they're in the
pg_catalog schema. You just need to replace a few lines with
public.datatype with
pg_catalog.datatype. For example
public.tsvector is now
pg_catalog.tsvector. For your information
gin_tsvector_ops is now
pg_catalog.tsvector_ops.
Finished? Good, but that's not all. You need to split up the file in two parts: one with the tables creation, and another one with the constraints creation. Why? Because otherwise the data insertion will fail because of these constraints. That's not so hard, just split your files in
wikidb-schema.sql with all
CREATE TABLE and so one, and then you see that the SQL file begins to do some
ADD CONSTRAINTS, just put this in another file, named
wikidb-constraints-schema.sql. You'll also need to set the namespace before executing command in your second file, so do not forget to add a
SET search_path = mediawiki, pg_catalog; line at the beginning.
Dump the database data
That's easy:
% pg_dump -a -n mediawiki wikidb > wikidb-data.sql
Create your new database
That's easy too:
% createuser -S -D -R -P -E wikiuser #(then enter the password)
% createdb -O wikiuser wikidb
% createlang plpgsql wikidb
Restore the database
That's even easier, but you need to respect this order, otherwise it will fail:
# Restore schema first
% psql wikidb < wikidb-schema.sql
# Then restore dat
% psql wikidb < wikidb-data.sql
# Then restore constraints
% psql wikidb < wikidb-constraints-schema.sql
Run update.php
Just go the the maintenance directory. Then you can try to run
update.php, but it'll fail.
% php update.php
[...]
Could not open "/var/www/awesome.naquadah.org/wiki/maintenance/postgres/archives/patch-tsearch2funcs.sql".
Well it seems that MediaWiki people just forgot this file in the 1.12 archive.. You can grab it on the SVN repository
here. When you've put it in the good directory, really run:
% php update.php
[...]
You should see no error. And now it works.
Give us some kudos
This is the last and hardest part of this tutorial. Since everything works, you should give kudos to Dimitri and me.
Adeodato Sim complains
about the many ways to regulate sound volume on his system. I can only add
that on my Dell Inspiron 9300, the “Master” is actually not usable
because it is mapped only to the tiny stereo speakers while leaving the
subwoofer alone, which is mapped to “Master Mono”. So I have to
use the pcm mixer.
At least I can map the buttons (both Fn+keyboard key and the additional
buttons at the front of the laptop) to the pcm mixer. But it took quite some
fiddling for something the non-technical user will expect work out of the
box.
Are
opticaljungle.com and publicdomainregistry.com
the same people?
Their addresses look identical but
their phone numbers are different.
Both appear to have some connections to directi.com.
Is there any way to check if they are
the same people?
I don't know how to verify US companies when they
appear not to want to be verified...
I was at two geek events in Zurich this week: At the 
We got back to Zurich late last night (not quite as late as we got into
Prague though, thankfully).
We stopped off in Deggendorf on the way through Germany to visit our friend
Christine from the 
versus
versus 
The first is the pretty internationally standard "no entry" sign, but when
you see the third sign in isolation, it seemed to us at least, that perhaps
that meant "no entry", where it actually means "no standing". "No parking"
is a variant of "no standing", with just one diagonal line. The middle
sign means "no vehicles", which makes no sense at all, unless you've seen
(and understood) the other versions of this sign, which have lesser
restrictions of "no cars" or "no bicycles" and feature an icon of either
inside the circle.
Speed limit signs were also a bit interesting. You'd have 
, which specifies
a speed limit, but then you'd have 
, which
means "End of speed limit". Our question was "well what is the speed limit
now?" The answer seems to be "the default national limit for the class of
road you're on".
The final set of signs we didn't understand until Christine explained them
to us when we saw her yesterday, were 
and 
, which
are "priority road" and "end of priority road", respectively. We just didn't
know what a priority road was. Turns out it means traffic on the priority
road has right of way over traffic on roads intersecting it. I would have
thought this was pretty obvious, but apparently on a non-priority road, you
have to give way to traffic on the right, regardless of whether you have a
stop sign or a yield/give-way sign. So there's some sort of implicit
four-way stop thing going on on a non-priority road.
Every time I see European traffic signs, particularly the triangular warning
signs, it gives me a flash back to my childhood. My Aunty Peggy used to have
a huge big bag of mixed Lego pieces, including a bunch of European traffic
signs, and some square Lego mats, and when we were kids, and we used to go
to her house to play, we'd build little towns out of all of the Lego.
This was the first time we've driven a manual left-hand drive car, and it
was fine, except your immediate subconscious reaction the first few times is
to go reaching for the gear stick with your left hand, and bash it into the
door. It was also the first time we've driven on a roundabout on the right
hand side of the road. That was interesting, because it added an additional
thing to think about: the traffic on the left.
Back from my travels, it's time for a few updates. I've mostly blogged about these elsewhere, so I'll just give some pointers here.
The 
The CIO and 
It’s not every day that your work is ignored by a founder of Mozilla Europe. From 
(This post is mostly as a reminder to myself on how I've set up my
backup system. It should probably go on a wiki instead so I can keep
it up to date.) After the recent OpenSSL debacle in Debian and
Ubuntu, I found that all my backups were encrypted with something
amounting to a well-known secret key. Ouch. I was not entirely happy
with how my old backup system worked either (it was based on