IBM 000-8697 Manuale Utente

Product Environment

The

TABLOCKS

logical log record can be written by either a coordinator or a

participant OnLine database server. It is associated with either a

BEGPREP

or

a

PREPARE

 record and contains a list of the locked tblspaces (by tblspace

number) held by the transaction. (Within the

IBM I

nformix

STAR

environment, transactions, not database server processes, are shown as the
owners of locks.)

The output from tblog contains three fields: type; number of locks, expressed
as an integer; and locked tblspace number, expressed as a hexadecimal. (If
you convert the hexadecimal value to an integer, the result is the value stored
as partnum in the systables system catalog table.) The output appears as
follows:

TABLOCKS number_of_locks hex_tblspace_number

The

HEURTX

 logical log record is written by a participant OnLine database

server to record a heuristic decision to roll back the transaction. It should be
associated with a standard

ROLLBACK

record indicating that the transaction

was rolled back.

The output from tblog contains two fields: type and a heuristic flag,
expressed as a hexadecimal. The value of the flag is always one. The output
appears as follows:

HEURTX 0x01

The

ENDTRANS

 logical log record is written by both the coordinator and

participant OnLine database servers to record the end of the transaction.

ENDTRANS

instructs OnLine to remove the transaction entry from its shared-

memory transaction table and close the transaction.

In the coordinator logical log, each

BEGPREP

 that results in a committed

transaction is paired with an

ENDTRANS

 record. If the coordinator’s final

decision is to roll back the transaction, no

ENDTRANS

 record is written.

In the participant logical log, each

ENDTRANS

 record is paired with a corre-

sponding

HEURTX

 record.