WHAT IS LAG IN OGG ?

GGSCI (tnc61.ffdc.com) 11> info all

Program              Status            Group       Lag at Chkpt  Time Since Chkpt

MANAGER     RUNNING                                           

EXTRACT     RUNNING     ENTNEW        3702:00:10   00:00:02    

EXTRACT     STARTING    EXTORD7      00:00:02      4582:06:49  

EXTRACT     STOPPED     PEXTORD7     00:00:00      4582:07:01  

EXTRACT     STOPPED     PXTNEW         00:00:00      4582:07:01  

REPLICAT    STOPPED     REORD117      00:00:00      4582:08:55  

LAG IN GOLDENGATE: Extract, Pump and Replicat in goldengate

Lag at Extract: lag is the difference in seconds between the time the record is captured on source table and database timestamp

Time since ckpt on extract: Time since extract collected last transaction on database, if the database has any long running transaction, we can see lag on this column

There are different types of checkpoints that Golden gate maintains for each process. You can see them using INFO <EXTRACT/PUMP/REPLICAT>, SHOWCH.

For example, for an extract, you will see the following read checkpoints:
- startup checkpoint
- recovery checkpoint
- current checkpoint
- BR recovery checkpoints

Lag at Replicat: lag is the difference in seconds record applied to the target table and timestamp of the record on remote trail

Time since ckpt on replicat:  Time since replicat applied last transaction on target table 

Lag at pump: lag is the difference in seconds record extracted from local trial and timestamp on the local trail