Re: [Firebird-devel] AutoOptimize

[Ann W. H. <aha...@ib...>]

= m. Th = wrote:
> 
> http://www.postgresql.org/docs/8.1/static/catalog-pg-autovacuum.html

Autovacuum is irrelevant as we already have on-line garbage collection
either cooperative or through a secondary thread.  Yes, their vacuum
does update statistics and Postgres keeps much more detailed index
statistics (e.g. histograms) than does Firebird.  Postgres also delays
optimization until query execution - and revises it during execution
to take advantage of values produces by an outer loop for example.

> 
> Something related is here
> http://www.postgresql.org/community/survey.41

This one is interesting....  We already have five and a half of
the eight most wanted new features in Postgres ... the world's
most advanced open source database.  Here's the list.

Allowing index scans to use an intermediate in-memory bitmap  	

Add two-phase commit 	

Create a new role system that replaces users and groups

Automatically use indexes for MIN() and MAX()

Move /contrib/pg_autovacuum into the main server 	

Add shared row level locks using SELECT ... FOR SHARE

Add dependencies on shared objects, specifically roles 	

Add an option to psql to automagically rollback errors without aborting 
the transaction 	
> 
> http://archives.postgresql.org/pgsql-bugs/2005-07/msg00101.php

which explains that autovacuum isn't sensitive to the amount of data
change, but considers one update equivalent to another in reaching
the threshold for garbage collection.  Firebird doesn't have that
problem at all.
> 
> 
> 
> Perhaps helps also
> 
> http://www.iiug.org/software/archive/utils2_ak
> 
Doesn't seem relevant to me.


Regards,


Ann