INF: SQL Memory Configuration Minimization

ID Number: Q67619

1.00 1.10

OS/2

docerr

Summary:

You cannot reduce the memory requirements to the 1000 page (or 2000K)

minimum specified in the SAF Config Menu option in SQL Server versions

1.0 and 1.1.

More Information:

The following figures are values that were obtained in a laboratory

while attempting to reduce the amount of SQL Server memory to the

minimum specification of 1000 pages (or 2000K).

SQL Server Version 1.1 Configuration Minimizations

--------------------------------------------------

These parameters are changeable from within SAF, using the Menu option

(on the Config menu), or through ISQL, using the sp_configure stored

procedure. Although the option screen states that a minimum memory

value of 1000 pages (2000K) is attainable, lab tests could not reduce

the memory below 1196 pages (2392K), even with all memory-intensive

parameters minimized.

WARNING: Pushing the parameters to these low limits will definitely

have a crippling effect on performance and lead to severe

thrashing. If all parameters are set to minimums or maximums, SQL

Server will demand an infinite amount of time to start.

We recommend that you use the parameters set at the time of

installation unless you are thoroughly familiar with how they

interact. (For example: For each user connection you add, SQL

Server demands an additional 40K of memory.)

SQL Server Memory Options Range

------------------------- -----

User connections [5] 5 to 1024 users

Each increment demands about 38K

(37.3K was the lab average)

>>> Memory [2392K] 2000K to 28,000K

2392K = 1196 Pages

(the lowest value obtained in the

lab)

Procedure cache [99%] 1 to 99 percent

Each decrement demands 2K

(this is opposite of expectations)

SQL Server General Options

--------------------------

Open databases [5] 5 to 100 databases

Two increments demand 2K

(1K average per increment)

Open Objects [120] 100 to 10,000 objects

Thirty increments demand 2K

(66 average per increment)

Locks [5000] 5000 to 50,000 locks

64 increments demand 2K

(31.25K average per increment)

*Fill Factor [0] 0 to 100 percent full pages

*Time slice [100] 50 to 1000 milliseconds

*Database size [2] 2 MB to 10,000 MB

(default value for each new

database)

*Media retention [0] 0 to 365 days

*Recovery flags [0] 0 (short) or 1 (verbose)

(Determines how much information

will be displayed during recovery.

Short is for headers only. Verbose

is for each individual transaction.)

SQL Server Dynamic Options

--------------------------

*Recovery interval [5] 1 to 32767 minutes

*Allow updates [0] 0 (no) or 1 (yes)

(*) denotes a parameter that places virtually no demand on memory.

Installation

------------

Multi-user SQL Server version 1.1 (update) on OS/2 version 1.21 and

OS/2 LAN Manager version 2.0a.