Postgresql – How to interpret backup_label contents?

Postgres version 11.

I’ve read this:

But can’t really find what I’m looking for.

Performing a basebackup creates 2 files for me: base.tar.gz and pg_wal.tar.gz

base.tar.gz contains a file backup_label

Which contains something like:

START WAL LOCATION: 5CD/87000850 (file 00000001000005CD00000087) CHECKPOINT LOCATION: 5CD/882A2558 BACKUP METHOD: streamed BACKUP FROM: master START TIME:  LABEL: pg_basebackup base backup START TIMELINE: 1 

And pg_wal.tar.gz contains this:

00000001000005CD00000087 00000001000005CD00000088 00000001000005CD00000089 00000001000005CD0000008A 00000001000005CD0000008B ... 00000001000005CD000000AF 

So, incremental files.

backup_label has a field START WAL LOCATION which literally points to 00000001000005CD00000087, the first file in the pg_wal.tar.gz archive.

Then it has CHECKPOINT LOCATION: 5CD/882A2558.

What is this "CHECKPOINT LOCATION"? I don’t see anything to correlate 882A2558 to. Or is that not intended?

Am I to interpret that as "The wal archives created while pg_basebackup was running are in pg_wal.tar.gz and they start at 5CD/87000850 and stop at 5CD/882A2558" ?

I’m just wondering: does pg_wal.tar.gz contain all the wal archives I need to do a successful restore? And if not, is there some other file that will provide me this info?

And if this is clearly written in the documentation, well I just read the entire page and didn’t recognize anything in there as the answer to my question? Did I miss it?