Hi,

How can i Set postgresql Read Only transaction? Is it oneness with

adapter.StartTransaction(IsolationLevel.Snapshot, "FEnt");

?

http://www.postgresql.org/docs/9.1/static/sql-set-transaction.html

Best Regards, MiloszeS

Is this property exposed by Postgres .NET provider?

I'm not sure .

I've found the possible pure sql usage.

begin transaction;

SET TRANSACTION READ ONLY;

SELECT ......

I can't find it anywhere on the net if this is exposed or not.

The isolation mode is a .NET enum, and it doesn't have a 'ReadOnly' value. So npgsql is (IMHO) only able to work with the enum values in the .NET enum IsolationLevel. The postgresql docs aren't really helpful about what readonly really means. Couldn't you use one of the other alternatives, e.g. serializable or snapshot?

Indeed there is a lack of documentation in this area. I've find out in one postgresql in the good practice section, that we should use read only transactions where its possible. Unfortunately they didn't wrote how it impacts the db. Currently I switched into the snapshot transaction in my case, but wondering whether additional switch to read only transaction will impact performance a little bit. I'll try to ask npgsql developers about that and eventually reopen this ticket.