On Wed, 2009-01-21 at 19:13 +0200, Heikki Linnakangas wrote: > Simon Riggs wrote: > > Why do we have 12+ pluggable languages, but we're not allowed to write > > pluggable indexes? Whatever argument you put against it being "too hard" > > or dangerous or whatever *also* applies to languages. Yet experience > > shows pluggability has resulted in a variety of robust and useful > > language types, some that might not have been predicted (PL/Proxy, PL/R > > etc). They cover a variety of users and situations. > > Languages are quite different. People already know language X, so they > want to use it for stored procedures too. Or they want to interface > other libraries or functionality available in language X. There's no > such argument with indexams. Also, PL handlers are not as tightly > integrated into the rest of the system, no need for low-level page > access, for example, which is why it's easier to have a generic > interface for them. There's also less issues with concurrency and > version-compatibility.
Yes, they allow people's external experience to be brought to Postgres. Which includes index experience. You're assuming that indexes must have concurrency and are therefore difficult to design. Concurrency isn't a requirement in many cases. You just need to store tids and feed them back. Indexes don't have to use database pages even. Robustness is a much more certain requirement, since rebuilding indexes from scratch may not even be practical in some cases. -- Simon Riggs www.2ndQuadrant.com PostgreSQL Training, Services and Support -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
