Re: PostgreSQL Lite for low-end/embedded systems (16MB of total memory) - Mailing list pgsql-general

From Tom Lane
Subject Re: PostgreSQL Lite for low-end/embedded systems (16MB of total memory)
Date
Msg-id 20289.1025452797@sss.pgh.pa.us
Whole thread Raw
In response to PostgreSQL Lite for low-end/embedded systems (16MB of total memory)  (Raphael Bossek <raphael.bossek@gmx.de>)
Responses Re: PostgreSQL Lite for low-end/embedded systems (16MB of total memory)  (Raphael Bossek <raphael.bossek@gmx.de>)
pg_upgrade  ("Mr. Shannon Aldinger" <god@yinyang.hjsoft.com>)
Re: PostgreSQL Lite for low-end/embedded systems (16MB of total memory)  (Raphael Bossek <raphael.bossek@gmx.de>)
List pgsql-general
Raphael Bossek <raphael.bossek@gmx.de> writes:
> do someone address the possibility to get the PostgreSQL
> working on systems or environments where the total memory
> does not exceed 16MB?

Define your terms, please.  Is that 16M of RAM, or disk space?
How much of it is actually available for Postgres, as opposed
to other stuff?  What is the OS (ie, do you have a porting problem
as well as a space problem)?

16M of RAM does not seem like much of a problem to me, as long as
you're envisioning a light-duty system (never more than a couple
concurrent backends, no need for lots of disk buffering).  With
the default parameter settings Postgres probably doesn't need more
than 8M of RAM.  (But this assumes Unix-like handling of memory,
in particular sharing of text pages between postmaster and its
child processes.)

But if you are talking 16M of disk then I think you are looking
at the wrong system.  Indeed I wonder why you think you need a
database at all.  If you only have a few meg of data to manage
then you hardly need SQL --- flat files searched with, say, grep
will do just fine.

> Support PostgreSQL to be embedded within an application to
> limit the inter process comunication "overhead" to achive better
> answer/respond results and limit the memory requirements of the
> environment?

Nope, and I don't think it's a good idea either.  Any sort of
client-side programming error could destroy your database.

Perhaps you would be better off looking at Berkeley DB, which
is an open-source database library that seems more in line with
what you want to do.

            regards, tom lane



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