在goldengate新版本中通过info extract, showch不会显示recovery checkpoint对应的seqno/rba，有时候为了准确定位读取的日志，希望能看到相应的seqno.
通过info extract，可以看到当前读取点，如下：
以下是集成抽取，当前读取点默认也未显示，只有当前时间及对应的scn
info ex1

EXTRACT EX1 Last Started 2021-03-02 13:47 Status RUNNING
Checkpoint Lag 00:00:04 (updated 00:00:02 ago)
Process ID 12554
Log Read Checkpoint Oracle Integrated Redo Logs
2021-03-03 10:48:33
SCN 0.9055659 (9055659)

这是传统抽取，可以看到当前读取点
info exc

EXTRACT EXC Last Started 2021-02-26 12:55 Status STOPPED
Checkpoint Lag 00:00:00 (updated 117:41:14 ago)
Log Read Checkpoint Oracle Redo Logs
2021-02-26 13:07:26 Seqno 376, RBA 898560
SCN 0.8638302 (8638302)

不过集成抽取可以使用send ex1, status看当前读取点
Sending STATUS request to EXTRACT EX1 ...
EXTRACT EX1 (PID 12554)
Current status: Recovery complete: Processing data

Current read position:
Redo thread #: 1
Sequence #: 396
RBA: 3632796
Timestamp: 2021-03-03 10:52:49.000000
SCN: 0.9055843 (9055843)
Current write position:
Sequence #: 12
RBA: 2476
Timestamp: 2021-03-03 10:52:49.041473
Extract Trail: ./dirdat/e1

这是集成抽取的showch日志，看不到recovery checkpoint对应的seqno/rba
Read Checkpoint #1

Oracle Integrated Redo Log

Startup Checkpoint (starting position in the data source):
Timestamp: 2021-02-02 15:11:22.000000
SCN: 0.0 (0)

Recovery Checkpoint (position of oldest unprocessed transaction in the data source):
Timestamp: 2021-03-03 10:48:48.000000
SCN: 0.9055668 (9055668)

Current Checkpoint (position of last record read in the data source):
Timestamp: 2021-03-03 10:48:48.000000
SCN: 0.9055668 (9055668)

经典抽取的showch日志，也看不到recovery checkpoint对应的seqno/rba
Read Checkpoint #1

Oracle Redo Log

Startup Checkpoint (starting position in the data source):
Timestamp: 2021-02-26 12:54:48.000000
SCN: 0.0 (0)

Recovery Checkpoint (position of oldest unprocessed transaction in the data source):
Timestamp: 2021-02-26 13:07:26.000000
SCN: 0.8638301 (8638301)

Current Checkpoint (position of last record read in the data source):
Timestamp: 2021-02-26 13:07:26.000000
SCN: 0.8638302 (8638302)

如果想看到recovery checkpoint对应的seqno/rba，则要使用下面的语法
info exc, showch debug
...
Startup Checkpoint (starting position in the data source):
Thread #: 1
Sequence #: 376
RBA: 897,552
Timestamp: 2021-02-26 13:07:26.000000
SCN: 0.8638301 (8638301)
Redo File: /u01/app/oracle/oradata/orcl/redo01.log

Recovery Checkpoint (position of oldest unprocessed transaction in the data source):
Thread #: 1
Sequence #: 396
RBA: 3,651,088
Timestamp: 2021-03-03 10:53:50.000000
SCN: 0.9055880 (9055880)
Redo File: /u01/app/oracle/oradata/orcl/redo03.log

Current Checkpoint (position of last record read in the data source):
Thread #: 1
Sequence #: 396
RBA: 3,652,096
Timestamp: 2021-03-03 10:53:50.000000
SCN: 0.9055881 (9055881)
Redo File: /u01/app/oracle/oradata/orcl/redo03.log

集成抽取的当前读取点，也可以这样看
info ex1 debug
EXTRACT EX1 Last Started 2021-03-02 13:47 Status RUNNING
Checkpoint Lag 00:00:10 (updated 00:00:04 ago)
Process ID 12554
Log Read Checkpoint Oracle Integrated Redo Logs
2021-03-03 10:54:19 Seqno 396, RBA 3661536
SCN 0.9055910 (9055910)