There are a couple of tools that will open an MDF file buy you have to pay for them
http://www.sqldatabaserepair.com/
http://www.mssqldatabaserecovery.com/

Another option is you need to learn how the MSSQL server is setup, and what version.

Get your hands on that Version of SQL install it and copy this file into the data directory then try to mount it.

If you fail to duplicate the setup of the server that created mdf file it can't be mounted. It will tell you the reason.

It would be easier if the people that sent you the MDF did a backup of the MSSQL Server, send you the backup, download a eval of MSSQL restore the backup then migrate.

Ary Pezo Silvano wrote:

hi,

thank you for your comments.

my problem is that the mdf file has been sent to me by email in a zip file.
i extracted the file and it is 8 GB. 
i don't know how i should import or open it with postgres.

best,
ary

________________________________________
Från: John R Pierce [pierce@hogranch.com]
Skickat: den 7 mars 2009 01:16
Till: Ary Pezo Silvano
Kopia: pgsql-general@postgresql.org
Ämne: Re: [GENERAL] mdf

Ary Pezo Silvano wrote:

hi,

how can i import a mdf database into postgres?


do you have access to the SQL Server that this MDF file came from?
Install the Postgres client for windows, along with a Postgres ODBC
driver on that server, and use the Data Translation Services in SQL
Server Enterprise to export the data from SQL Server to Postgres (which
can be on a different server, using a postgres network connection, if
you setup everything correctly).


Otherwise, use SQL Server to export the tables seperately as CSV files,
and import them into Postgres.