Q1. Do you know what AIS versions support server side cursors?
A1. Support was added to AIS V5.0.1 as a temp feature.

Q2. Do we need a specific version of SQL Server for that to work?

A2.Server side cursors are supported from Microsoft SQL Server ODBC Drivers version 2.50.0121 or later when running against Microsoft SQL Server version 6.0 or later. However, this capability had (and still have) bugs and limitation, so, the newer the version the more smooth it will work.

Q3. How do I make the driver to use them? Is there a config property or a temporary feature?

A3.Define a temp feature mssqlOdbcGetCursorsMode with the a value of 1 to 4 as follows:

1 -- client side cursor with multiple connection - default and previous behaviour
2 -- server side cursor with multiple connection
3 -- client side cursor with single connection
4 -- server side cursor with single connection

The initial setting of this temp feature should be '4'. If this causes
problems other modes can be attempted with value '1' turning this temp feature off. Depending on the version of SQL Server, some limitations existed whereby you may need to use server side cursors with one connection per statement (for example the limitation of multiple result sets with SP).

Q4. Are server side cursors needed only for updates? If yes, are they recommended also for read only access?

A4.The server side cursors are, in fact, mostly used for reading in multiple cursors within the same transaction scope. Using them you use less connections and gain bettern consistency. Unless you have problems using it, it should be the recommended way of working.