IBM 000-8697 Manual Do Utilizador

Product Environment

You can also use the information in the

HEURTX

 log record to locate all log

records (at all participating OnLine database servers) associated with the
global transaction of which this local transaction is just a piece. The steps
involved are as follows:

Obtain the local xid from the

HEURTX

 log record at a participant

OnLine where the transaction rolled back.

Look for a

PREPARE

log record for that local xid and obtain the global

transaction number (

GTRID

) and the name of the coordinating

OnLine. (Refer to

for more information about the GTRID.)

Examine the logical log maintained by the coordinator OnLine and
locate the

BEGPREP

 record for this global transaction.

Read the

BEGPREP

 log record and obtain the coordinator’s local xid

for the transaction.

Read the long listing of the

BEGPREP

record to obtain a list of all other

participants.

At each participant OnLine, read the logical log to find the

PREPARE

record that contains the

GTRID

 associated with this transaction and

obtain the local xid for the piece of work performed by this
participant.

At each participant OnLine, use the local xid to locate all logical log
records associated with this transaction (committed or rolled back).

Use the records you find and your knowledge of the application to
help you construct a compensating transaction that either rolls back
the committed effects of the transaction or commits the pieces of
work that were rolled back.

This example is intended to illustrate the kind of work that is involved in
manual recovery. The following SQL statements were executed by user pault.
Error -698 was returned.

<prompt> dbaccess
CREATE DATABASE tmp WITH LOG;
CREATE TABLE t ( a int);
CLOSE DATABASE;
CREATE DATABASE tmp@apex WITH LOG;
CREATE TABLE t ( a int);
CLOSE DATABASE;