Marin Alonso, David wrote:
> Hi all
>
> All people have advised me that I should migrate my database Postgres 7.2.2
>
> /PostgreSQL 7.2.2 on i686-pc-linux-gnu, compiled by GCC gcc (GCC) 3.2
> 20020903 (/
>
> /Red Hat Linux 8.0 3.2-7)/
>
> *to new version 8.1.4.*
>
> //
>
> I have downloaded
>
> *
> /postgresql-8.1.4-1PGDG.i686.rpm/
> *
> /postgresql-contrib-8.1.4-1PGDG.i686.rpm/
> *
> /postgresql-server-8.1.4-1PGDG.i686.rpm/
> *
> /postgresql-libs-8.1.4-1PGDG.i686.rpm/
>
> I have done backup from databases before installing, but I don´t know
> what are the steps to migrate to new version?
>
> Somebody could tell me what are the steps or where I can find
> information about these kind of migrations
>
>
>
> Thanks in advance
>
As to the details of what an RPM installation does for you and what you
must do manually in terms of making the appropriate user, installing
startup scripts, running initdb, etc. I can't be of much assistance as I
generally install from source. Perhaps someone else can help with that.
But I do have the following advice.
First and foremost, install PostgreSQL 8.1.4 on a *development* machine
(as similar as possible in architecture and OS to your production
machine). In addition to becoming familiar/comfortable with the upgrade
process, you will also be able to:
1. Make sure PG 8.1.4 installs and runs.
2. Make sure the databases restore correctly.
3. Verify that your apps still function correctly. Yes, 8.1.4 is *way*
ahead of 7.2.x in almost every way bit it is also different. Over time,
PG has become more correct/strict. If, for example, you have a text
column and a query that casts the text to int, a blank would cast
without error in 7.2 but in 7.4+ you need to make sure the text
represents a valid number before casting (blank does not qualify) or an
error will be generated. If your app depends on the loose checking in
old versions, you will need to update your app to avoid illlegal
casting. That is just one example. You may also need to check that all
the clients that attach to your server still function correctly (and
ultimately plan upgrades for those, as well, where appropriate). Peruse
the release notes all the way from your current version up to the
current to get an idea of possible issues.
4. Adjust postgresql.conf and pg_hba.conf. Note: pg_dumpall does not
save these files - you must save them manually. Also, there are new
options that you may wish to adjust.
Please don't just make a backup, blow away the old PG and hope the
install, restore and app will all work fine.
Cheers,
Steve