Example Description

address

is the address of the buffer header in the buffer table.

userthread

is the address of the most recent user thread to access the buffer table. Many user threads might be reading the same buffer concurrently.

flgs

uses the following flags to describe the buffer:

0x01

Modified data

0x02

Data

0x04

LRU

0x08

Error

pagenum

is the physical page number on the disk.

memaddr

is the buffer memory address.

nslots

is the number of slot-table entries in the page. This field indicates the number of rows (or portions of a row) that are stored on the page.

pgflgs

uses the following values, alone or in combination, to describe the page type:

1

Data page

2

Tblspace page

4

Free-list page

8

Chunk free-list page

9

Remainder data page

b

Partition resident blobpage

c

Reserved

d

Blob chunk free-list bit page

e

Blob chunk blob map page

10

B-tree node page

20

B-tree root-node page

40

B-tree branch-node page

80

B-tree leaf-node page

100

Logical-log page

200

Last page of logical log

400

Sync page of logical log

800

Physical log

1000

Reserved root page

2000

No physical log required

8000

B-tree leaf with default flags

xflgs

uses the following flag bits to describe buffer access

0x10

share lock

0x80

exclusive lock

owner

is the user thread that sets the xflgs buffer flag.

waitlist

is the address of the first user thread that is waiting for access to this buffer. For a complete list of all threads waiting for the buffer, refer to "onstat -X".

The maximum number of buffers available is defined by the BUFFERS onconfig parameter.

The -b and -B options also provide summary information about the number of modified buffers, the total number of buffers, the number of hash buckets, and the buffer size.

123 modified, 200 total, 256 hash buckets, 4096 buffer size