onstat -x

Use the -x option to display transaction information on the database server. The transaction information is required only in the following situations:

Example Output

Figure 112. onstat -x Output

IBM Informix Dynamic Server Version 10.00.UC1  -- On-Line -- Up 03:58:41 -- 15360 Kbytes

Transactions
address  flags userthread locks  beginlg curlog  logposit   isol    retrys coord
a509018  A---- a4d8018    0      0       6       0x17304c   COMMIT  0      
a5091e8  A---- a4d8628    0      0       0       0x0        COMMIT  0      
a5093b8  A---- a4d8c38    0      0       0       0x0        COMMIT  0      
a509588  A---- a4d9248    0      0       0       0x0        COMMIT  0      
a509758  A---- a4d9858    0      0       0       0x0        COMMIT  0      
a509928  A---S a4d9e68    1      0       0       0x0        COMMIT  0      xps_qa
6 active, 128 total, 8 maximum concurrent

Output Description

You can interpret output from onstat -x as follows:

address

Is the shared-memory address of the transaction structure

flags

The flag codes for position 1 (current transaction state):

A: User thread attached to the transaction
S: TP/XA suspended transaction
C: TP/XA waiting for rollback

The flag codes for position 2 (transaction mode):

T: Tightly-coupled mode (MTS)
L: Loosely-coupled mode (default mode)

The flag codes for position 3 (transaction stage):

B: Begin work
P: Distributed query prepared for commit
X: TP/XA prepared for commit
C: Committing or committed
R: Rolling back or rolled back
H: Heuristically rolling back or rolled back

The flag code for position 4:

X: XA transaction

The flag codes for position 5 (type of transaction):

G: Global transaction
C: Distributed query coordinator
S: Distributed query subordinate
B: Both distributed query coordinator and subordinate

userthread

Is the thread that owns the transaction (rstcb address)

locks

Is the number of locks that the transaction holds

beginlg

Is the log in which the BEGIN WORK record was logged

curlog

Is the current log that the transaction is writing to

logposit

Is the log position

The format of a 4-byte log position is 0xPPPPPBBB, where PPPPP is the page offset in the log and BBB is the byte offset in the page. The logposit can refer to a maximum of 0x100000 (or 1048576) pages in a log file.

For example, a record on the first page of log 12, at a byte offset of 24 would have a log position of 0x18 (page 0, byte offset 18). For more information, see Determining the Position of a Logical-Log Record.

isol

Is the isolation level.

retrys

Are the attempts to start a recovery thread for the distributed query

coord

Is the name of the transaction coordinator when the subordinate is executing the transaction

This field tells you which database server is coordinating the two-phase commit.

The last line of the onstat -x output indicates that 8 is the maximum number of concurrent transactions since you initialized the database server.

8 active, 128 total, 8 maximum concurrent