Product Environment 9-57

IBM Informix STAR Configuration Parameters

1. Find all records that were updated.
2. Identify their type (insert, delete, update) using the table on
page 7-57.
3. Use thetblog -l output for each record to obtain the local xid, the
tblspacenumber, and the rowid. (Refer to page 7-55 for a description
of thetblog -l header.)
4. Mapthe tblspace number to a table name by comparing the tblspace
numberto the value in the partnum column of the systables system
catalog table.
5. Using your knowledge of the application, determine what action is
required to correct the situation.
Inthis example, it is possible to see that the timestamps on the COMMIT and
ROLLBACKrecords in the different logs are close. No other active transactions
introduce the possibility of another concurrent commit or rollback. In this
case, an insert (HINSERT) of assigned rowid 102 hexadecimal (258 decimal)
was committed on the current server. Therefore, the compensating trans-
action is as follows:
DELETE FROM t WHERE rowid = 258
IBM Informix STAR Configuration Parameters
Two configuration file parameters are specific toIBM Informix STAR:
■DEADLOCK_TIMEOUT
■TXTIMEOUT
Although both parameters specify time-out periods, the two are
independent.

DEADLOCK TIMEOUT

If a distributed transaction within an IBMInformix STAR environment is
forced to wait longer than the number of seconds specified by
DEADLOCK_TIMEOUT for a shared-memory resource, the database server
processthat owns the transaction assumes that a multiserver deadlock exists.
The following error message is returned:
-154 ISAM error: deadlock timeout expired - Possible deadlock.