SEO

I've got a question, when I take a database snapshot in V8, I get 4
bufferpools back for memory usage. But when I then do a snapshot on
bufferpools I only get 1 back. The size in that snapshot for that 1
bufferpool is also a lot smaller then the size specified in the database
snapshot.
So what is this information in the database snapshot?

Memory Pool Type = Buffer Pool Heap
Current size (bytes) = 4227072
High water mark (bytes) = 4227072
Maximum size allowed (bytes) = 4294950912

Memory Pool Type = Buffer Pool Heap
Current size (bytes) = 557056
High water mark (bytes) = 557056
Maximum size allowed (bytes) = 4294950912

Memory Pool Type = Buffer Pool Heap
Current size (bytes) = 294912
High water mark (bytes) = 294912
Maximum size allowed (bytes) = 4294950912

Memory Pool Type = Buffer Pool Heap
Current size (bytes) = 163840
High water mark (bytes) = 163840
Maximum size allowed (bytes) = 4294950912

Memory Pool Type = Buffer Pool Heap
Current size (bytes) = 98304
High water mark (bytes) = 98304
Maximum size allowed (bytes) = 4294950912


From the bufferpool snapshot the memory information is:
Node number = 0
Tablespaces using bufferpool = 4
Alter bufferpool information:
Pages left to remove = 0
Current size = 1000
Post-alter size = 1000

Thanks.

buffer pool heap != buffer pool
Getting buffer pool information either through:
get snapshot for bufferpools on <dbname>
or
the "bufferpool snapshot" part in db snapshot.
Regards,
FRX

Erik Hendrix wrote:

> I've got a question, when I take a database snapshot in V8, I get 4
> bufferpools back for memory usage. But when I then do a snapshot on
> bufferpools I only get 1 back. The size in that snapshot for that 1
> bufferpool is also a lot smaller then the size specified in the database
> snapshot.
> So what is this information in the database snapshot?
>
> Memory Pool Type = Buffer Pool Heap
> Current size (bytes) = 4227072
> High water mark (bytes) = 4227072
> Maximum size allowed (bytes) = 4294950912
>
> Memory Pool Type = Buffer Pool Heap
> Current size (bytes) = 557056
> High water mark (bytes) = 557056
> Maximum size allowed (bytes) = 4294950912
>
> Memory Pool Type = Buffer Pool Heap
> Current size (bytes) = 294912
> High water mark (bytes) = 294912
> Maximum size allowed (bytes) = 4294950912
>
> Memory Pool Type = Buffer Pool Heap
> Current size (bytes) = 163840
> High water mark (bytes) = 163840
> Maximum size allowed (bytes) = 4294950912
>
> Memory Pool Type = Buffer Pool Heap
> Current size (bytes) = 98304
> High water mark (bytes) = 98304
> Maximum size allowed (bytes) = 4294950912
>
> From the bufferpool snapshot the memory information is:
> Node number = 0
> Tablespaces using bufferpool = 4
> Alter bufferpool information:
> Pages left to remove = 0
> Current size = 1000
> Post-alter size = 1000
>
> Thanks.

In DB2 UDB V8.1, each buffer pool is now self contained in a buffer pool
heap. This is different from V7.2 where information on descriptors, etc. was
kept in the DBHEAP. In V8.1 each buffer pool heap contains all you need for
a single buffer pool. Now why the 4 extra? We have a hidden bufferpool and
hence a bufferpool heap for each of the 4 page sizes we support. This is to
allow you to be able to activate/connect to your database and do minimal
processing in the event that you cannot allocate your defined bufferpool
memory requirements.

Does that help?

Bob

"Erik Hendrix" <hendrix_erik@hotmail.com> wrote in message
news:26fb0b8ea621b2da34e7dea07ce5af17@free.teranew s.com...
> I've got a question, when I take a database snapshot in V8, I get 4
> bufferpools back for memory usage. But when I then do a snapshot on
> bufferpools I only get 1 back. The size in that snapshot for that 1
> bufferpool is also a lot smaller then the size specified in the database
> snapshot.
> So what is this information in the database snapshot?
>
> Memory Pool Type = Buffer Pool Heap
> Current size (bytes) = 4227072
> High water mark (bytes) = 4227072
> Maximum size allowed (bytes) = 4294950912
>
> Memory Pool Type = Buffer Pool Heap
> Current size (bytes) = 557056
> High water mark (bytes) = 557056
> Maximum size allowed (bytes) = 4294950912
>
> Memory Pool Type = Buffer Pool Heap
> Current size (bytes) = 294912
> High water mark (bytes) = 294912
> Maximum size allowed (bytes) = 4294950912
>
> Memory Pool Type = Buffer Pool Heap
> Current size (bytes) = 163840
> High water mark (bytes) = 163840
> Maximum size allowed (bytes) = 4294950912
>
> Memory Pool Type = Buffer Pool Heap
> Current size (bytes) = 98304
> High water mark (bytes) = 98304
> Maximum size allowed (bytes) = 4294950912
>
>
> From the bufferpool snapshot the memory information is:
> Node number = 0
> Tablespaces using bufferpool = 4
> Alter bufferpool information:
> Pages left to remove = 0
> Current size = 1000
> Post-alter size = 1000
>
> Thanks.
>
>

Hey Bob,

Yes, that helped enormously. Thanks. That explains it.

"Bob [IBM]" <NoSpamPlease@ibm.com> wrote in message
news:bfekbh$hfi$1@news.btv.ibm.com...
> In DB2 UDB V8.1, each buffer pool is now self contained in a buffer pool
> heap. This is different from V7.2 where information on descriptors, etc.
was
> kept in the DBHEAP. In V8.1 each buffer pool heap contains all you need
for
> a single buffer pool. Now why the 4 extra? We have a hidden bufferpool
and
> hence a bufferpool heap for each of the 4 page sizes we support. This is
to
> allow you to be able to activate/connect to your database and do minimal
> processing in the event that you cannot allocate your defined bufferpool
> memory requirements.
>
> Does that help?
>
> Bob
>
> "Erik Hendrix" <hendrix_erik@hotmail.com> wrote in message
> news:26fb0b8ea621b2da34e7dea07ce5af17@free.teranew s.com...
> > I've got a question, when I take a database snapshot in V8, I get 4
> > bufferpools back for memory usage. But when I then do a snapshot on
> > bufferpools I only get 1 back. The size in that snapshot for that 1
> > bufferpool is also a lot smaller then the size specified in the database
> > snapshot.
> > So what is this information in the database snapshot?
> >
> > Memory Pool Type = Buffer Pool Heap
> > Current size (bytes) = 4227072
> > High water mark (bytes) = 4227072
> > Maximum size allowed (bytes) = 4294950912
> >
> > Memory Pool Type = Buffer Pool Heap
> > Current size (bytes) = 557056
> > High water mark (bytes) = 557056
> > Maximum size allowed (bytes) = 4294950912
> >
> > Memory Pool Type = Buffer Pool Heap
> > Current size (bytes) = 294912
> > High water mark (bytes) = 294912
> > Maximum size allowed (bytes) = 4294950912
> >
> > Memory Pool Type = Buffer Pool Heap
> > Current size (bytes) = 163840
> > High water mark (bytes) = 163840
> > Maximum size allowed (bytes) = 4294950912
> >
> > Memory Pool Type = Buffer Pool Heap
> > Current size (bytes) = 98304
> > High water mark (bytes) = 98304
> > Maximum size allowed (bytes) = 4294950912
> >
> >
> > From the bufferpool snapshot the memory information is:
> > Node number = 0
> > Tablespaces using bufferpool = 4
> > Alter bufferpool information:
> > Pages left to remove = 0
> > Current size = 1000
> > Post-alter size = 1000
> >
> > Thanks.
> >
> >
>
>