Re: Is PostgreSQL multi-threaded? - Mailing list pgsql-general

From JanWieck@t-online.de (Jan Wieck)
Subject Re: Is PostgreSQL multi-threaded?
Date
Msg-id 200005300858.KAA11376@hot.jw.home
Whole thread Raw
In response to Re: Is PostgreSQL multi-threaded?  (Lincoln Yeoh <lylyeoh@mecomb.com>)
Responses Re: Is PostgreSQL multi-threaded?
List pgsql-general
Lincoln Yeoh wrote:
> At 10:28 PM 29-05-2000 -0400, Joseph Shraibman wrote:
> >So in other words, it *is* multithreaded.  It just uses heavyweight
> >threads.
>
> I call those ropes ;). A lot more robust, but give your system enough of
> them it'll hang itself.

    If  performance goes down because of missing computing power,
    more threads won't make it better.

    You're better off by designing the application to use  pooled
    DB connections, like AOL-Server for example.

    Multithreading  is  kinda  Buzzword,  and  many  people today
    believe it is the  solution  for  all  performance  problems.
    Well,  starting  a thread is faster, consumes less resources,
    yada, yada. But they forget about the problems.

    All threads live in the same address  space.  In  PostgreSQL,
    someone  can  write  his own C functions, and run them in his
    test database. If such a function is buggy, should it be able
    to   corrupt   the  memory  of  another  thread  serving  the
    production DB?

    Threads have OS specific limits. Linux  for  example  doesn't
    support  the POSIX call to set the per thread stack limit. It
    manages them dynamically up to 2MB. In other OSs you have  to
    decide what's the estimated required stack size.

    What  counts  for a DB server is speed and reliability. But I
    think it's a bad decision to gain  speed  from  mucking  with
    reliability.


Jan

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