by Hi! I don't want to say SQL Server is bad, but It is allways funny to see
how MS compares itself to others. I just readed following quotes from
"Microsoft Inside SQL Server 6.5"
by Ron Soukup. Published by Microsoft press.
page 39:
...Quote:> Traditional Process/Thread Model
> To understand and contrast the architecture of Microsoft SQL Server, it
> is useful for you to first understand the traditional architectures that
> have been used by UNIX-based DBMS products. UNIX-based DBMS products are
> usually structured in one of two ways. In the first way, multiple
> processes (or shadow processes) are used, with one process per user,
> which makes the system quite resource intensive. The second type of
> architecture employs a single process that tries to simulate an
> operating system threading facility by moving in a round-robin way among
> multiple requests, maintaining a stack for each request and switching
> to that specific stack for whatever unit is being executed.
[explanations why these are bad]
page 40:
...Quote:> Microsoft SQL Server Process/Thread Model
> A thread (more formally called a thread of execution and sometimes
> referred to as a lightweight process) is the executable unit on the
> Windows NT operating system. Threads, not processes, are scheduled for
> execution by Windows NT.
> Rather than move a single thread among all user tasks, SQL Server
> employs a pool of threads.
[explanations why it is good]
page 41:
Good... Now I have a some questions:Quote:> ... SQL Server's process/thread model greatly exceeds the reliability
> of typical UNIX-based database servers.
1. What is a _traditional_ UNIX-based DBMS?
2. What is a _typical_ UNIX-based DBMS?
3. Why Ron Soukup thinks that typical UNIX-based DBMS doesn't have a
third approach that uses threads provided by UNIX OS-es... or maybe
he thinks UNIX-es doesn't have threads? Then what makes him think
this one?
--
Asko Seeba.