Re: how to build a database from scratch

From: DBMS_Plumber <paul_geoffrey_brown_at_yahoo.com>
Date: 8 Dec 2006 10:29:46 -0800
Message-ID: <1165602586.856070.60230@l12g2000cwl.googlegroups.com>

paul c wrote:

> This is getting further and further away from the original question (at
> least the single answer "use a btree" to the original question) which I
> understood to be - does a BTREE algorithm need to change to allow
> concurrency. The answer is no if tasks or processes independent from
> the btree ones are used, eg., a logical lock manager (one that locks
> values, not blocks) and a transaction's updates are flushed together.

Please look up "Halloween Problem".

Having understood it, explain please how you can solve it with a logical lock manager and by flushing updates.

Please look up "Concurrency Tree Locking".

Having understood it, explain how it can be implemented with a logical lock manager and by flushing updates.

There are perhaps a score of other challenges that apply at the purely physical level of B-Tree implementations which I could rabbit on about. For these reasons, none of the world's commercial B-Tree implementations employs the naive B-Tree algorithms as anything more than a rough outline. Received on Fri Dec 08 2006 - 12:29:46 CST