Re: Materialized views WIP patch

On 2/21/13 9:25 AM, Kevin Grittner wrote:
> Peter Eisentraut <peter_e@gmx.net> wrote:
>> On 2/20/13 11:14 PM, Greg Stark wrote:
>>> That's not entirely true. From the database's point of view,
>>> TRUNCATE is in many ways actually DDL.
>>
>> Whether something is DDL or DML or a read operation (query) is
>> not an implementation detail, it's a user-exposed category. 
>> Since TRUNCATE is logically equivalent to DELETE, it's a DML
>> operation, as far as the user is concerned.
> 
> Not really.  It doesn't follow the same MVCC behavior as DML.  This
> is user-visible, documented behavior.

MVCC behavior does not determine whether something is considered DDL or DML.