> there are three catagories of memory useage
>
> 1. needed by other software
> 2. available for postgres
> 3. needed by the OS
There's actually only two required memory questions:
M1) How much RAM do you have on this machine?
M2) Is this:
() Dedicated PostgreSQL Server?
() Server shared with a few other applications?
() Desktop?
I don't think the "mostly reads / mostly writes" question covers anything,
nor is it likely to produce accurate answers. Instead, we need to ask the
users to characterize what type of application they are running:
T1) Please characterize the general type of workload you will be running on
this database. Choose one of the following four:
() WEB: any scripting-language application which mainly needs to support
90% or more data reads, and many rapid-fire small queries over a large
number of connections. Examples: forums, content management systems,
directories.
() OLTP: this application involves a large number of INSERTs, UPDATEs and
DELETEs because most users are modifying data instead of just reading it.
Examples: accounting, ERP, logging tools, messaging engines.
() Data Warehousing: also called "decision support" and "BI", these
database support a fairly small number of large, complicated reporting
queries, very large tables, and large batch data loads.
() Mixed/Other: if your application doesn't fit any of the above, our
script will try to pick "safe, middle-of-the-road" values.
Hmmm, drop question (6) too.
(2) should read: "What is the maximum number of database connections which
you'll need to support? If you don't know, we'll pick a default."
Other questions we need:
How many/how fast processors do you have? Pick the option which seems
closest to what you have:
() A single laptop processor
() Single or dual older processors (1ghz)
() Dual or quad current consumer processors (2ghz+)
() Large, recent multi-core server system
"What OS Are You Using", of course, needs to have Linux, Solaris, BSD, OSX
and Windows. At some point, this tool will also need to generate for the
user any shmem settings that they need to make on the OS.
--
--Josh
Josh Berkus
PostgreSQL @ Sun
San Francisco
