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Onstat -a -b/-B -C -c -d/-D -F -f -G -h -i -j -k/-K -L -l -m -o -P -p -R -r -s -t/-T -u -X -x -z

onstat -X Sharers and waiters for buffers

The onstat -X command displays the sharers and waiters for buffers.

Buffers (Access)
address          owner            flags pagenum          memaddr          nslots pgflgs scount   waiter

Buffer pool page size: 2048
 47 modified, 3000000 total, 4194304 hash buckets, 2048 buffer size

Buffer pool page size: 16384
 637 modified, 500000 total, 524288 hash buckets, 16384 buffer size

Output Description

Heading Description Format See Also
address Address of the buffer header in the Resident Memory buffer pool.   onstat -b
owner The address of the userthread currently accessing this buffer. This address corresponds to the address field given by the onstat -u command.   onstat -u
flgs Flags identifying the current status of the buffer page
  0x01    Modified Data
  0x02    Data
  0x04    LRU
  0x08    Error
  0x20    LRU AIO write in progress
  0x40    Chunk write in progress
  0x80    Buffer is/will be result of read-ahead
  0x100   Cleaner assigned to LRU
  0x200   Buffer should avoid bf_check calls
  0x400   Do log flush before writing page
  0x800   Buffer has been ‘buff’-checked
  0x8000  Buffer has been pinned
  0x10000 Buffer modified by fuzzy operation
  0x20000 Use aging of buffer on LRU
  0x40000 Don’t use buffer priorities
  onstat -b
pagenum The physical page number of this page on disk    
memaddr The buffer memory address    
nslots The number of slot table entries (i.e., rows or row portions) on this page.    
pgflgs Describes the page type
  0x01   Data Page
  0x02   Partition Page
  0x04   Bitmap Page
  0x08   Chunk Free List Page
  0x09   Remainder Data Page
  0x0b   Partition Resident BLOB Page
  0x0c   BLOBSpace Resident BLOB Page
  0x0d   BLOB Chunk Free List Bitmap Page
  0x0e   BLOB Chunk BLOB Map Page
  0x10   B+ Tree Node Page
  0x20   B+ Tree Root Node Page
  0x40   B+ Tree Branch Node Page
  0x80   B+ Tree Leaf Node Page
  0x100  Logical Log Page
  0x200  Last Page of Logical Log
  0x400  Sync Page of Logical Log
  0x800  Physical Log Page
  0x1000 Root Reserved Page
  0x2000 No Physical Logging Required
  0x4000 No Physical Logging Required (load-time)
  0x8000 B-Tree Leaf with deleted entries
  0x20   Secondary partition header (w/0x02)
  0x40   Alter description partition header (w/0x02)
  0x80   Key descriptor partition page (w/0x02)
  0x80   Generic page
  0x4000 Do not allocate a row without checking
  onstat -b
scount A count of the number of threads sharing this buffer.    
waiter A list of the threads waiting for this buffer.    

Summary Definitions

Label Description See Also
modified The total number of buffers in the pool that have been modified since the last buffer flush (e.g., from a checkpoint) onstat -R
total The total number of buffers as allocated by the BUFFERS parameter in the configuration file. onstat -R
hash buckets The number of hash buckets created to track the pages placed into the buffer pool. onstat -h
buffer size The size of an individual buffer. This is determined at port time and is not configurable. onstat -R


    The onstat -X command is similar in output to the onstat -b/-B commands.

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