Re: max_wal_size

On Thu, May 28, 2020 at 12:21:14PM +0300, p.luzanov@postgrespro.ru wrote:
> WAL |-----------|-----+-----|-----+-----|-----+----->
> 
>                    a           b           c  
> CP              +-----+     +-----+     +-----+
>                 b     e     b     e     b     e
> 
> Checkpointer process for point A starts at a(b) and ends at a(e).
> At the end of the work, CP makes a WAL record(plus symbol on WAL line).
> 
> Back to the max_wal_size description:
> "Maximum size to let the WAL grow to between automatic WAL checkpoints."
> 
> As I understand now, this is true when we talk about the checkpoint as a
> process.
> "Maximum size to let the WAL grow to between a(b) and b(e), between b(b) and c
> (e), etc".

What if we say:

    "Maximum size to let the WAL grow during automatic WAL checkpoints."

That highlights the "process" part.

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  Bruce Momjian  <bruce@momjian.us>        https://momjian.us
  EnterpriseDB                             https://enterprisedb.com

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