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Re: ADMIN Migrate postgres databases from SQL_ASCII to UNICODE

From: "Patrice Trognon" <trognon(dot)patrice(at)wanadoo(dot)fr>
To: "Markus Bertheau" <twanger(at)bluetwanger(dot)de>
Cc: "Dario V(dot) Fassi" <software(at)sistemat(dot)com(dot)ar>,pgsql-admin(at)postgresql(dot)org
Subject: Re: ADMIN Migrate postgres databases from SQL_ASCII to UNICODE
Date: 2004-07-18 11:27:52
Message-ID: 20040718132752.6475772@devptro.(none) (view raw or flat)
Thread:
Lists: pgsql-admin
Hi,

If you have blobs you must split your SQL_ASCII to convert it
with iconv.
I export my full database.
I create a new SQL_ASCII database with only tables that don't
contains blobs. (db_without_blobs)
I create a new SQL_ASCII database with only tables that contains
blobs. (db_with_blobs)
Export your db_without_blobs.
convert it with iconv
Create your UNICODE database.
import db_without_blobs.
import db_with_blobs.

It's done.

1) export your database. 
/usr/local/postgres/bin/pg_dump -Fc -v -b -d -U YOUR_LOGIN YOUR_DATABASE > full_database.dump 

2) create work database, without blobs.
/usr/local/postgres/bin/createdb db_without_blobs

3) import all datas
/usr/local/postgres/bin/pg_restore -d db_without_blobs -Fc -v -U YOUR_LOGIN full_database.dump 

4) create work database, with blobs.
/usr/local/postgres/bin/createdb db_with_blobs

5) import all datas.
/usr/local/postgres/bin/pg_restore -d db_with_blobs -Fc -v -U YOUR_LOGIN full_database.dump 

6) Connect to db_without_blobs and drop all tables with blobs.
6') Connect to db_with_blobs and drop all tables without blobs.

7) export datas in text mode :
/usr/local/postgres/bin/pg_dump -Fp -v -i -D -U YOUR_LOGIN  db_without_blobs > db_without_blobs.dump 

8) convert into UTF-8 
iconv --from-code=ISO-8859-1 --to-code=UTF-8 -o db_without_blobs-utf.dump db_without_blobs.dump 

9) Create unicode database.
/usr/local/postgres/bin/createdb  -E UNICODE db_unicode

10) importat UTF-8 datas
/usr/local/postgres/bin/psql db_unicode < db_without_blobs.dump 

11) export datas with blobs in binary format.
12) import this dump info db_unicode .

Best Regards,

Patrice Trognon.






> В Вск, 18.07.2004, в 01:34, Dario V. Fassi пишет:
> > Tom Lane wrote:
> > > "Dario V. Fassi" <software(at)sistemat(dot)com(dot)ar> writes:
> > >   
> > > > A simple question, we need to migrate many (>20) postgres databases from 
> > > > SQL_ASCII encoding to UNICODE encoding, over a 7.3.6 server.
> > > >     
> > > SQL_ASCII is not an encoding (it's more like the absence of knowledge
> > > about an encoding).  What is the data actually stored as?
> > >   
> > > > With  Dump/Restore , we get an error (Invalid Unicode) in any field that 
> > > > has a 8 bits character coming from the SQL_ASCII , even setting the 
> > > > client_encoding to WIN, ISO-8859-1,  and others encodings.
> > > >     
> > > It might work to just UPDATE pg_database to set datencoding to the
> > > correct value reflecting what you have actually stored.  You might then
> > > need to REINDEX any indexes on textual columns, but I don't think
> > > anything else would go wrong.
> > > 
> > > If you have a mishmash of different encodings in a single database, then
> > > of course there is no simple solution; you are in for some pain while
> > > you try to fix the data.
> > >   
> > 
> > Yes you are right , the original data come from a DB2 with CodePage
> > IBM-850  and was inserted  without complains in a Postgres 7.3.6 with
> > SQL_ASCII.
> > 
> > Now we are in a Jail , because IBM-850 , isn't WIN, isn't  ISO-xx ,
> > isn't no one postgresql's encoding. 
> > So when in change via pg_databases the encoding , 8 bits characters
> > become garbage.
> > More even if we accept this garbage chars and we set encoding to e.g.
> > ISO-8859-1   it's impossible go to a UNICODE because this garbage
> > chars are invalid in client's encoding , so they are reject (in
> > translation process as invalid unicode chars).
> 
> You can dump the data, convert it with for example iconv and then load
> the data again.
> 
> -- 
> Markus Bertheau <twanger(at)bluetwanger(dot)de>
> 
> 
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Next:From: Dario V. FassiDate: 2004-07-18 19:47:20
Subject: Re: [ADMIN] Migrate postgres databases from SQL_ASCII to UNICODE
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Subject: Re: Migrate postgres databases from SQL_ASCII to UNICODE

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