Re: isolation check takes a long time

Excerpts from Noah Misch's message of mar jul 17 16:28:32 -0400 2012:
> 
> On Tue, Jul 17, 2012 at 01:56:19PM -0400, Alvaro Herrera wrote:

> > However, there's more work to do in isolation testing.  It'd be good to
> > have it being routinely run in serializable isolation level, for
> > example, not just in read committed.
> 
> Except for the foreign key specs, isolation test specs request a specific
> isolation level when starting their transactions.  Running such specs under
> different default_transaction_isolation settings primarily confirms that
> "BEGIN TRANSACTION ISOLATION LEVEL x" is indistinguishable from "BEGIN" under
> default_transaction_isolation = x.  It might also discover transaction
> isolation sensitivity in the setup/cleanup steps, which often omit explicit
> transaction control.  I don't think such verification justifies regularly
> running thousands of tests.  The foreign key tests, however, would benefit
> from running under all three isolation levels.  Let's control it per-spec
> instead of repeating the entire suite.

Understood and agreed.  Maybe we could use a new directive in the spec
file format for this.

-- 
Álvaro Herrera <alvherre@commandprompt.com>
The PostgreSQL Company - Command Prompt, Inc.
PostgreSQL Replication, Consulting, Custom Development, 24x7 support