Datalink manager log records are the result of DDL, DML, or completion of
transaction events involving DATALINK columns. These log records are
written only when the DDL or the DML involves DATALINK columns with the file
link control attribute.
Table 133. Datalink Manager Log Record Header Structure (DLMLogRecordHeader)
| Description | Type | Offset (Bytes) | ||
|---|---|---|---|---|
| Component identifier (=8) | unsigned char | 0(1) | ||
| Function identifiera | unsigned char | 1(1) | ||
| padding | char [] | 2(2) | ||
| Total Length: 6 bytes | ||||
| ||||
The link file log record is written when an insert or an update on a table
with a DATALINK column creates a link to a file. One log record is
written for each new link that is created. This log record is only used
for undo.
Table 134. Link File Log Record Structure
| Description | Type | Offset (Bytes) |
|---|---|---|
| Log header | DLMLogRecordHeader | 0(4) |
| ServerId | long | 4(4) |
| ReadOnly | int | 8(4) |
| AuthId | char [] | 12(8) |
| GroupId | char [] | 20(17) |
| padding | char [] | 37(1) |
| AccessControl | unsigned short | 38(2) |
| PrefixId | char [] | 40(9) |
| padding | char [] | 49(3) |
| RecoveryId | char [] | 52(7) |
| padding | char [] | 59(1) |
| Time stamp | unsigned long | 60(4) |
| StemNameLen | unsigned long | 64(4) |
| StemName | variable | 68(variable) |
| Total Length: 68 bytes plus StemNameLen | ||
The unlink file log record is written when a delete or an update on a table
with a DATALINK column drops a link to a file. One log record is
written for each link that is dropped. This log record is only used for
undo.
Table 135. Unlink File Log Record Structure
| Description | Type | Offset (Bytes) |
|---|---|---|
| Log header | DLMLogRecordHeader | 0(4) |
| ServerId | long | 4(4) |
| PrefixId | char [] | 8(9) |
| padding | char [] | 17(3) |
| RecoveryId | char [] | 20(7) |
| padding | char [] | 27(1) |
| Time stamp | unsigned long | 28(4) |
| StemNameLen | unsigned long | 32(4) |
| StemName | variable | 36(variable) |
| Total Length: 36 bytes plus StemNameLen | ||
The delete group log record is written when a table with DATALINK columns
(having the file link control attribute) is dropped. One log record is
written for each such DATALINK column for each DB2 Data Links Manager
configured to the database. For a given DB2 Data Links Manager, the log
record is written only if that DB2 Data Links Manager has the group defined on
it when the table is dropped. This log record is only used for
undo.
Table 136. Delete Group Log Record Structure
| Description | Type | Offset (Bytes) |
|---|---|---|
| Log header | DLMLogRecordHeader | 0(4) |
| ServerId | long | 4(4) |
| RecoveryId | char [] | 8(7) |
| padding | char [] | 15(1) |
| GroupId | char [] | 16(17) |
| padding | char [] | 33(3) |
| Total Length: 36 bytes | ||
The delete pgroup log record is written when a table space is
dropped. One log record is written for each DB2 Data Links Manager
configured to the database. For a given DB2 Data Links Manager, the log
record is written only if that DB2 Data Links Manager has the pgroup defined
on it when the table space is dropped. This log record is only used for
undo.
Table 137. Delete PGroup Log Record Structure
| Description | Type | Offset (Bytes) |
|---|---|---|
| Log header | DLMLogRecordHeader | 0(4) |
| ServerId | long | 4(4) |
| poolLifeLSN | SQLU_LSN | 8(6) |
| poolId | unsigned short | 14(2) |
| RecoveryId | char [] | 16(7) |
| padding | char [] | 23(1) |
| Total Length: 24 bytes | ||
The DLFM prepare log record is written during the prepare phase, when a
two-phase commit is used for transactions involving DB2 Data Links
Managers. It is used to recreate a transaction for DB2 Data Links
Managers that are in-doubt.
Table 138. DLFM Prepare Log Record Structure
| Description | Type | Offset (Bytes) |
|---|---|---|
| Log header | DLMLogRecordHeader | 0(4) |
| NumDLFMs | unsigned short | 4(4) |
| ServerIds | variable | 8(variable) |
| Total Length: 8 bytes plus (NumDLFMs * 4) | ||