API Reference

Transaction Manager Log Records

The transaction manager produces log records signifying the completion of transaction events (for example, commit or rollback). The time stamps in the log records are in Coordinated Universal Time (CUT), and mark the time (in seconds) since January 01, 1970.

Normal Commit

This log record is written for XA transactions in a single-node environment, or on the coordinator node in MPP. It is only used for XA applications. The log record is written when a transaction commits after one of the following events:

A user has issued a COMMIT
An implicit commit occurs during a CONNECT RESET.

Table 106. Normal Commit Log Record Structure

Description Type Offset (Bytes)
Log header LogManagerLogRecordHeader 0(20)
Time transaction committed unsigned long 20(4)
Authorization identifier of the application^a char [ ] 24(9)
Total Length: 33 bytes propagatable (24 bytes non-propagatable)

Note: ^a If the log record is marked as propagatable

Heuristic Commit

This log record is written when an indoubt transaction is committed.

Table 107. Heuristic Commit Log Record Structure

Description Type Offset (Bytes)
Log header LogManagerLogRecordHeader 0(20)
Time transaction committed unsigned long 20(4)
Authorization identifier of the application^a char [ ] 24(9)
Total Length: 33 bytes propagatable (24 bytes non-propagatable)

Note: ^a If the log record is marked as propagatable

MPP Coordinator Commit

This log record is written on a coordinator node for an application that performs updates on at least one subordinator node.

Table 108. MPP Coordinator Commit Log Record Structure

Description Type
Log header LogManagerLogRecordHeader
MPP identifier of the transaction SQLP_GXID
Maximum node number 2 bytes
TNL variable, (max node no / 8) + 1
Authorization identifier char [ ]

Description	Type
Log header	LogManagerLogRecordHeader
MPP identifier of the transaction	SQLP_GXID
Maximum node number	2 bytes
TNL	variable, (max node no / 8) + 1
Authorization identifier	char [ ]

MPP Subordinator Commit

This log record is written on a subordinator node in MPP.

Table 109. MPP Subordinator Commit Log Record Structure

Description Type Offset (Bytes)
Log header LogManagerLogRecordHeader 0(20)
MPP identifier of the transaction SQLP_GXID 20(20)
Authorization identifier char [ ] 40(9)
Total Length: 49 bytes

Description	Type	Offset (Bytes)
Log header	LogManagerLogRecordHeader	0(20)
MPP identifier of the transaction	SQLP_GXID	20(20)
Authorization identifier	char [ ]	40(9)
Total Length: 49 bytes

Normal Abort

This log record is written when a transaction aborts after one of the following events:

A user has issued a ROLLBACK
A deadlock occurs
An implicit rollback occurs during crash recovery
An implicit rollback occurs during ROLLFORWARD recovery.

Table 110. Normal Abort Log Record Structure

Description Type Offset (Bytes)
Log header LogManagerLogRecordHeader 0(20)
Authorization identifier of the application^a char [ ] 20(9)
Total Length: 29 bytes propagatable (20 bytes non-propagatable)

Note: ^a If the log record is marked as propagatable

Heuristic Abort

This log record is written when an indoubt transaction is aborted.

Table 111. Heuristic Abort Log Record Structure

Description Type Offset (Bytes)
Log header LogManagerLogRecordHeader 0(20)
Authorization identifier of the application^a char [ ] 20(9)
Total Length: 29 bytes propagatable (20 bytes non-propagatable)

Note: ^a If the log record is marked as propagatable

Local Pending List

This log record is written if a transaction commits and a pending list exists. The pending list is a linked list of nonrecoverable operations (such as deletion of a file) that can only be performed when the user/application issues a COMMIT. The variable length structure contains the pending list entries.

Table 112. Local Pending List Log Record Structure

Description Type Offset (Bytes)
Log header LogManagerLogRecordHeader 0(20)
Time transaction committed unsigned long 20(4)
Authorization identifier of the application^a char [ ] 24(9)
Pending list entries variable 33(variable)
Total Length: 33 bytes plus pending list entries propagatable (24 bytes plus pending list entries non-propagatable)

Note: ^a If the log record is marked as propagatable

Global Pending List

This log record is written if a transaction involved in a two-phase commit commits, and a pending list exists. The pending list contains nonrecoverable operations (such as deletion of a file) that can only be performed when the user/application issues a COMMIT. The variable length structure contains the pending list entries.

Table 113. Global Pending List Log Record Structure

Description Type Offset (Bytes)
Log header LogManagerLogRecordHeader 0(20)
Time transaction committed unsigned long 20(4)
Authorization identifier of the application^a char [ ] 24(9)
Global pending list entries variable 32(variable)
Total Length: 33 bytes plus pending list entries propagatable (24 bytes plus pending list entries non-propagatable)

Note: ^a If the log record is marked as propagatable

XA Prepare

This log record is written for XA transactions in a single-node environment, or on the coordinator node in MPP. It is only used for XA applications. The log record is written to mark the preparation of the transaction as part of a two-phase commit. The XA prepare log record describes the application that started the transaction, and is used to recreate an indoubt transaction.

Table 114. XA Prepare Log Record Structure

Description Type Offset (Bytes)
Log header LogManagerLogRecordHeader 0(20)
Log space used by transaction unsigned long 20(4)
XA identifier of the transaction variable 24(140)
Application name char [ ] 164(20)
Application identifier char [ ] 184(32)
Sequence number char [ ] 216(4)
Authorization identifier char [ ] 220(8)
Database alias used by client char [ ] 228(20)
Code page identifier unsigned long 248(4)
Time transaction prepared unsigned long 252(4)
Synclog information variable 256(variable)
Total Length: 256 bytes plus variable

Description	Type	Offset (Bytes)
Log header	LogManagerLogRecordHeader	0(20)
Log space used by transaction	unsigned long	20(4)
XA identifier of the transaction	variable	24(140)
Application name	char [ ]	164(20)
Application identifier	char [ ]	184(32)
Sequence number	char [ ]	216(4)
Authorization identifier	char [ ]	220(8)
Database alias used by client	char [ ]	228(20)
Code page identifier	unsigned long	248(4)
Time transaction prepared	unsigned long	252(4)
Synclog information	variable	256(variable)
Total Length: 256 bytes plus variable

MPP Subordinator Prepare

This log record is written for MPP transactions on subordinator nodes. The log record is written to mark the preparation of the transaction as part of a two-phase commit. The MPP subordinator prepare log record describes the application that started the transaction, and is used to recreate an indoubt transaction.

Table 115. MPP Subordinator Prepare Log Record Structure

Description Type Offset (Bytes)
Log header LogManagerLogRecordHeader 0(20)
Log space used by transaction unsigned long 20(4)
Coordinator LSN unsigned char 24(6)
MPP identifier of the transaction SQLP_GXID 30(20)
Application name char [ ] 50(20)
Application identifier char [ ] 70(32)
Sequence number char [ ] 102(4)
Authorization identifier char [ ] 106(8)
Database alias used by client char [ ] 114(20)
Code page identifier unsigned long 134(4)
Time transaction prepared unsigned long 138(4)
Total Length: 142 bytes

Description	Type	Offset (Bytes)
Log header	LogManagerLogRecordHeader	0(20)
Log space used by transaction	unsigned long	20(4)
Coordinator LSN	unsigned char	24(6)
MPP identifier of the transaction	SQLP_GXID	30(20)
Application name	char [ ]	50(20)
Application identifier	char [ ]	70(32)
Sequence number	char [ ]	102(4)
Authorization identifier	char [ ]	106(8)
Database alias used by client	char [ ]	114(20)
Code page identifier	unsigned long	134(4)
Time transaction prepared	unsigned long	138(4)
Total Length: 142 bytes

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