onstat -g mem Memory Pool Statistics

The onstat -g mem command displays statistics on the memory pools created during operation of the system.

Pool Summary:                                                             
name         class addr     totalsize freesize #allocfrag #freefrag       
resident     R     a002020  11763712  4472     2          2               
res-buff     R     ab3a020  153608192 4472     2          2               
global       V     14002020 950272    222816   1409       116             
mt           V     14007020 7012352   656056   7473       185             
smartblob    V     14067020 4096      1368     3          1               
sbtlist      V     14068020 8192      1512     4          1               
sb_delq      V     1406a020 28672     8432     4          3               
sb_delundoq  V     14083020 28672     8432     4          3               
sb_lofd      V     1409c020 28672     8392     5          3               
sb_loheader  V     140ad020 28672     7896     5          3               
sbspace tab  V     140c6020 8192      4024     5          2               
sb_arcspace  V     140c9020 4096      736      5          1               
sb_chunk_ad  V     140cb020 8192      1368     5          1               
rsam         V     140d2020 1220608   20720    2358       32              
aio          V     14121020 2379776   119160   571        197             
gls          V     14126020 28672     5760     348        4               
......
112          V     14e21020 212992    46016    337        59        
123          V     14d92020 184320    37000    303        49        
112.SES.SAP  V     14e5b020 86016     7504     449        41        
124          V     14ee5020 114688    40264    138        28        
124.SES.SAP  V     14f4e020 24576     7128     99         5         
201          V     1500c020 12288     4648     13         2         
125.SES.SAP  V     15036020 24576     6872     101        15        
1398         V     14c29020 12288     4648     13         2         
                                                                    
Blkpool Summary:                                                    
name         class addr     size      #blks                         
global       V     14004858 0         0                             
Blkpool Summary:
name               addr             size      #blks      
global       V     140048580        0         0         
xmf_msc_pl   V     14eb40200        954368    73       
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Pool Summary

Heading	Description	Format	See Also
name	The name of the pool.	Str
class	The shared memory segment type in which the pool has been created (R, V, or M).	Str	onstat -g seg
addr	The in-memory address of the pool.	Hex
totalsize	The total size of the pool in bytes.	Dec
freesize	The number of bytes of free memory within this pool.	Bytes
#allocfrag	The number of allocated fragments within this pool.	Dec
#freefrag	The number of free fragments within this pool.	Dec

Blkpool Summary

Heading	Description	Format
name		Str
class	The shared memory segment type in which the pool has been created (R, V, or M).	Str
addr	The in-memory address of the pool.	Hex
size	The size of the pool in bytes.	Dec
#blks	The number of 8K blocks that make up this pool.	Dec
pre-hint	No longer available	Int
szavail	No longer available	Int

Notes

Regular memory pools are a dynamically growing/shrinking collection of (4kB) random memory blocks, assigned to e.g. a session or a specific activity (of a session), with a somewhat complex internal structure allowing for 'used' and 'free' fragments book keeping.

Block pools, in contrast, consist of larger contiguous blocks of memory for certain purposes requiring large and e.g. page size aligned memory, e.g. a larger sort or also stacks, and without much internal structure - so just a large chunk of memory to use and to later discard as a whole once done with the task.

Thanks to Andreas Legner for pool clarification

This command does NOT show the VP memory cache, to see that then onstat -g vpcache