Dilan Arumainathan wrote:
>I am trying to migrate a database from Oracle to Postgresql. I am using the
>PgAdmin database migration wizard (1.5.60-Dev) to do this. Using ODBC I am
>able to migrate small tables but I have a few tables that have over 10
>million rows that are failing. I know the reason as I am getting an
>"Snapshot too old" error from Oracle but am unable to come up with a
>workaround. I prefer using the wizard as it takes care of nulls etc. which I
>might have to handle if I went the dump and load route. Can someone give me
>an idea on getting around this (other than preventing updates to Oracle).
>
>Also, is there a way to turn off WAL while loading bulk data.
>
>thanks
>dilan
>
Hi Dilan,
this is an well known problem in Oracle.
(I know its off topic, but it might interest other people)
You got several options around it:
- Increase the size of your rollback segments (the message means, that
Oralce cannot give you a consistent view)
See
http://download-west.oracle.com/docs/cd/A87860_01/doc/server.817/a76965/c23cnsis.htm#2599
- Stop all other transactions
- Do the work in serveral steps
- Use a script like "unload.sql" ( in the Attachement, from
http://www.evergreen-database.com/)
( it doesn not prevent the problem, but is quite performant)
I hope I could help you with that.
Cheers, Dani