Thread: how to understand checkpoint information in pg_control data

Hello Experts,

I have couple of questions on pg_controldata output. 

postgres=# \! pg_controldata $PGDATA|grep checkpoint
Latest checkpoint location:           2/9D029BB0,  
Latest checkpoint's REDO location:    2/97002D60
Latest checkpoint's REDO WAL file:    000000030000000200000097    
Latest checkpoint's TimeLineID:       3
Latest checkpoint's PrevTimeLineID:   3
Latest checkpoint's full_page_writes: on
Latest checkpoint's NextXID:          0:1732072
Latest checkpoint's NextOID:          40985
Latest checkpoint's NextMultiXactId:  1
Latest checkpoint's NextMultiOffset:  0
Latest checkpoint's oldestXID:        561
Latest checkpoint's oldestXID's DB:   1
Latest checkpoint's oldestActiveXID:  1731942
Latest checkpoint's oldestMultiXid:   1
Latest checkpoint's oldestMulti's DB: 1
Latest checkpoint's oldestCommitTsXid:0
Latest checkpoint's newestCommitTsXid:0
Time of latest checkpoint:            Fri 28 Jun 2019 02:59:24 PM GMT

What is "Latest checkpoint location" 
what is  "Latest checkpoint's REDO location". to my understanding, it is records lsn number. correct me if I am wrong?

Latest checkpoint's REDO WAL file:    000000030000000200000097,  to my understanding  this wal file has the latest record lsn , from where recovery will start and rollover. please correct me if I am wrong ?