On Mar 30, 11:10 am, "Woody Ling" <woodyl...@gmail.comwrote:

From the DB2 UDB memory model document, I found the following info:

==============================

The agent private memory set consist of the following memory pools.

Their sizes are specified in the database configuration parameters

enclosed in parenthesis:

Application Heap (applheapsz)

Sort Heap (sortheap)

Statement Heap (stmtheap)

Statistics Heap (stat_heap_sz)

Query Heap (query_heap_sz)

Java Interpreter Heap (java_heap_sz)

===============================

Since I am now using a 32bits DB2 in AIX and the agent private memory

area is limited to max 256MB, I wonder how my existing setting can be

handled by DB2:

Application Heap (applheapsz) 512 ~= 2MB

Sort Heap (sortheap) 10240 ~= 40MB

Statement Heap (stmtheap) 32767 ~= 134MB

Statistics Heap (stat_heap_sz) 20000 ~= 82MB

Query Heap (query_heap_sz) 1024 ~= 4MB

Java Interpreter Heap (java_heap_sz) 2048 ~= 8MB

Total 270 MB per agent that is larger than the limitation of the agent

private memory segment in AIX.

Actually I can have 7 concurrent applications with intra-parallel ON

that 2-4 agents are assigned to one application. How can these agents

fit into the 256MB agent private memory segment in AIX? Does db2

agents only get what it need? These settings are hard limit only?

Hi Woody,

These values are only hard limits - we'll only use that much memory

for each heap if and when needed. Also, some of these heaps are

mutually-exclusive - the statistics heap is only used when gathering

table statistics (i.e. the runstats command), and the statement heap

is only used when compiling/optimizing an SQL query before running it

(so, a single agent won't be using the statement heap at the same time

as the sort heap, for example).

Cheers,

Liam.