is there any way to keep redundant copy of current wall log on same server? means, as soon as transaction commits, it it going to make an entry in wal log and the same log in different location ?
1. my postgres did not recovered/read all the wal logs that are existed in wal location?
It did read all necessary WAL files in the ARCHIVE directory. It failed when it tried to read "*01A" which, as you noted in your experiment, never made it to the archive.
-rw-------. 1 postgres postgres 16777216 Mar 4 06:25 00000001000000000000001A >>>>> file has latest table test table , log swith not completed so far
Its doesn't get shipping until it fills up or you execute, as you did in the experiment,
===== >>> force manual swtich
postgres=# select pg_switch_wal();
2. what is the best way to instruct postgresql to read and apply all the logs are presented on wal location ?
There are two "wal location(s)" - please be more specific as to which one you are referring to.
Now, in a server crash situation where you don't blow up the entire data directory (or local WAL directory if kept separate - a recommended practice), the original WAL files would all be available and would all be read so the recovery gap would be significantly reduced.
