database Share Memory Limit (2 GB ) in a Instance is total of all Db shared memory of all databases in a single Instance!!

sadanjan

Hi ,

Appreciate if someone can clarify if database Share Memory Limit
(2 GB ) in Unix 32 bit boxes is the top limit for all the databases
put together in a database or is it for each of the database in an
Instance
Thanks & regards
sadanjan

Jul 21 '06 #1

Liam Finnie

sa******@gmail.com wrote:

Hi ,

Appreciate if someone can clarify if database Share Memory Limit
(2 GB ) in Unix 32 bit boxes is the top limit for all the databases
put together in a database or is it for each of the database in an
Instance
Thanks & regards
sadanjan

Hi Sadanjan,

This limit is per-database, you can have multiple active databases,
with each database using the 2GB limit on UNIX 32-bit instances (on
Windows 32-bit, the overall sum of memory used by DB2 is limited to the
2GB virtual memory limit, or 3GB using the special /3GB boot option).
However, depending on your particular OS (AIX/Linux/Solaris/HP-UX), you
might need to do some OS and DB2 tuning to be able to actually allocate
the full 2GB for the database. Also, this will limit the amount of
instance-wide shared memory (INSTANCE_MEMORY), and private memory
(stmtheap, applheapsz, etc) that can be allocated. If your databases
are already pushing close to this limit, you're probably better off
using the 64-bit version of DB2.

Cheers,
Liam.

Jul 21 '06 #2

Mark A

"Liam Finnie" <lf*****@ca.ibm.comwrote in message
news:11**********************@b28g2000cwb.googlegr oups.com...

>
Hi Sadanjan,

This limit is per-database, you can have multiple active databases,
with each database using the 2GB limit on UNIX 32-bit instances (on
Windows 32-bit, the overall sum of memory used by DB2 is limited to the
2GB virtual memory limit, or 3GB using the special /3GB boot option).
However, depending on your particular OS (AIX/Linux/Solaris/HP-UX), you
might need to do some OS and DB2 tuning to be able to actually allocate
the full 2GB for the database. Also, this will limit the amount of
instance-wide shared memory (INSTANCE_MEMORY), and private memory
(stmtheap, applheapsz, etc) that can be allocated. If your databases
are already pushing close to this limit, you're probably better off
using the 64-bit version of DB2.

Cheers,
Liam.

I believe that the 2GB limit is per instance not per database. However, you
can easily have more than one instance per server.

Jul 21 '06 #3

Pierre Saint-Jacques

No the limit is per db.
It's the Global Shared Memory of the db that is limited by the 2GB.
If memory serves, the limit is actually 1.75 GB for single node, single
processor. 1.5 GB if either Database Partionning Facility or Synetric Muti
Processor enabled (Poof! there went another 256MB segment). A look at the
Quick Beginnings specifies all of this for each OS and its versions.
HTH, Pierre.

--
Pierre Saint-Jacques
SES Consultants Inc.
514-737-4515
"Mark A" <no****@nowhere.coma écrit dans le message de news:
Y9******************************@comcast.com...

"Liam Finnie" <lf*****@ca.ibm.comwrote in message
news:11**********************@b28g2000cwb.googlegr oups.com...

>>
Hi Sadanjan,

This limit is per-database, you can have multiple active databases,
with each database using the 2GB limit on UNIX 32-bit instances (on
Windows 32-bit, the overall sum of memory used by DB2 is limited to the
2GB virtual memory limit, or 3GB using the special /3GB boot option).
However, depending on your particular OS (AIX/Linux/Solaris/HP-UX), you
might need to do some OS and DB2 tuning to be able to actually allocate
the full 2GB for the database. Also, this will limit the amount of
instance-wide shared memory (INSTANCE_MEMORY), and private memory
(stmtheap, applheapsz, etc) that can be allocated. If your databases
are already pushing close to this limit, you're probably better off
using the 64-bit version of DB2.

Cheers,
Liam.

I believe that the 2GB limit is per instance not per database. However,
you can easily have more than one instance per server.

Jul 22 '06 #4