On 01/09/2017 06:47 AM, Tom DalPozzo wrote:
https://www.postgresql.org/docs/9.5/static/wal-internals.html
<https://www.postgresql.org/docs/9.5/static/wal-internals.html>
"After a checkpoint has been made and the log flushed, the
checkpoint's position is saved in the file pg_control. Therefore, at
the start of recovery, the server first reads pg_control and then
the checkpoint record; then it performs the REDO operation by
scanning forward from the log position indicated in the checkpoint
record. Because the entire content of data pages is saved in the log
on the first page modification after a checkpoint (assuming
full_page_writes is not disabled), all pages changed since the
checkpoint will be restored to a consistent state."
Hi, yes I know that, it's what I meant in my point 3). As it says first
"the checkpoint's position (NOT the record)is saved in the file
pg_control" then I had some doubt.
Yes it is just one piece of information stored in the file.
To see what else is stored there do:
pg_controldata -D your_cluster_data_directory
Regards
Pupillo
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Adrian Klaver
adrian.klaver@xxxxxxxxxxx
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