Re: Migrate postgres databases from SQL_ASCII to UNICODE - Mailing list pgsql-admin

From Dario V. Fassi
Subject Re: Migrate postgres databases from SQL_ASCII to UNICODE
Date
Msg-id 40F9B776.9050601@sistemat.com.ar
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Responses Re: Migrate postgres databases from SQL_ASCII to UNICODE
List pgsql-admin
Tom Lane wrote:
"Dario V. Fassi" <software@sistemat.com.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).

We are in a big problem, and the only way out I can imagine is fix the data by hand  :-! .

Dario,

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