RPK wrote:
> I want to know whether MVCC has cons also. Is it heavy on resources? How
> PGSQL MVCC relates with SQL Server 2005 new Snapshot Isolation.
>
Speaking as an end-user, I can give only one I've ever seen, which is
performance. Because of MVCC, Postgres's write performance (insert and
update) appears on my systems to be almost exactly linear to row size.
Inserting 1000 rows into a table with row size 100 characters takes
twice as long as inserting 1000 rows into a table with row size 50
characters.
This tends to be more of an issue for me because my system materializes
derived information in columns, so my tables are more fat to begin with,
and so this hits me harder.
--
Kenneth Downs
Secure Data Software, Inc.
www.secdat.com www.andromeda-project.org
631-689-7200 Fax: 631-689-0527
cell: 631-379-0010