[ZODB-Dev] Re: AW: diploma thesis: ZODB Indexing

[Christian Theune]

Hi,

Am Mittwoch, den 05.09.2007, 21:47 +0100 schrieb Laurence Rowe:
> Make sure you take a look at SQLAlchemy's implementation of this, 
> sqlalchemy.orm.query.

Thanks for the tip.

> RDBMS do not get fast querying for free... They just revert to a 
> complete record scan when they do not have an index - analogous to the 
> find tab in the ZMI. As anyone who has ever queried such a database can 
> attest, it ain't quick. (RDBMSs tend to create implicit indexes on 
> primary and foreign keys also.)

Well. They do have some support on the storage side because of the
strong typed rectangular shape. E.g. we discovered that postgres seems
to never do index lookups in tables with less than about 1000 rows --
for us it always did table scans even when indexes existed.