Dear Van L. Loggins ,
>What methods are available to easily backup the contents of a PostgreSQL database?
>
>
PostgreSQL both file system backup option and SQL data in form of
insert statement :
Note: I have done this thing with > PostgreSQL 7.3
This is what I do
1. Take a file system backup of PostgreSQL "data" folder preferably
with DUMP
2. Take a back up of data with
pg_dump --disable-triggers -U <USER NAME> -a -d -b -D -Fc -Z 9
-f filename.tar.gz <DATABASE NAME>
a. This will take care of blobs (Though 7.2 does not have it)
b. Make sure that your data be less than 8 GB as tar could not
handle more than that
3. Yes Schema is also required to be backed up with above command and
having switch as
pg_dump --disable-triggers -U <USER NAME> -s Fp -f
schema.sql <DATABASE NAME>
4. Now why Schema is dumped separately to that of data
Because :
a. pg_dump will dump the schema as per its own wish and not as per
the database requirement so
if a required user defined function is not in the secema dump as
early as it is required your pg_restore will
abort with Xmas bells
b. In this case you can rearrange the creation of Schema as
Create functions > then table > then sequences > then views
5. Now after all stuff you have done install your new OS
initdb a new database in the same directory location as it was in
the old one (i.e in the older OS)
6. Now try restore the Schema if succeeds then go to 7 else
rearrange your sql statements to satisfy the monster
7. Restore Data with
pg_restore --disable-triggers -U <USER NAME> -d <DATABASE NAME>
./filename.tar.gz
8. Now if 6 and 7 fails you have a chance reinstall the older version
of postgresql and also its DUMP file to regain the data and schema again
and start again from point 2 to 8
This is what I do to restore / migrate and have got 100 % results till date
Any one having a better and more reliable method please pass it on to
Anjan Dave and me
We would be grateful to you
Regrads,
V Kashyap
