Re: Reasoning behind process instead of thread based

>
> On some operating systems, like Windows and Solaris, processes are
> expensive, while threads are cheap, so to speak.  this is not the case
> in Linux or BSD, where the differences are much smaller, and the
> multi-process design suffers no great disadvantage.

Even on Windows or Solaris you can use techniques like persistent
connections or connection pooling to eliminate the process overhead.

> Actually, if it were converted to multi-threaded tomorrow, it would
> still be true, because the postgresql engine isn't designed to split off
> queries into constituent parts to be executed by seperate threads or
> processes.  Conversely, if one wished to implement it, one could likely
> patch postgresql to break up parts of queries to different child
> processes of the current child process (grand child processes so to
> speak) that would allow a query to hit multiple CPUs.
>

I would be curious as to what this would actually gain. Of course there
are corner cases but I rarely find that it is the CPU that is doing all
the work, thus splitting the query may not do you any good.

In theory I guess being able to break it up and execute it to different
CPUs could cause the results to process faster, but I wonder if it would
be a large enough benefit to even notice?

>>"We also provide MySQL Server as an embedded multi-threaded library that
>>you can link into your application to get a smaller, faster,
>>easier-to-manage product."
>>
>>Do PostgreSQL offer anything similar?

No, it isn't really designed to do that. Like Oracle also is not a
database you would Embed.

> pick PostgreSQL, it's generally considered a bad thing to have a
> database crash mid transaction.  PostgreSQL is more robust about crash
> recovery, but still...
>
> That's another subject that shows up every x months, an embedded version
> of PostgreSQL. Basically, the suggestion is to use something like
> SQLlite, which is built to be embedded, and therefore has a much lower
> footprint than PostgreSQL could ever hope to achieve.  No one wants
> their embedded library using up gobs of RAM and disk space when it's
> just handling one thread / process doing one thing.  It's like
> delivering Pizzas with a Ferrari, you could do it, it just eouldn't make
> a lot of sense.
>
>
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