On 2020-10-21 15:54, lchch1...@sina.cn wrote:
I think it's really a more convenient way to collect wal usage
information,
with it we can query when I want. Several points on my side:
Thanks for your comments.
1. It will be nice If you provide a chance to reset the information in
WalStats,
so that we can reset it without restart the database.
I agree.
Now, pg_stat_wal supports reset all informantion in WalStats
using pg_stat_reset_shared('wal') function.
Isn't it enough?
2. I think 'wal_write_backend' is mean wal write times happen in
backends. The describe in document is not so clear, suggest rewrite
it.
OK, I'll rewrite to "Total number of times backends write WAL data to
the disk".
3. I do not think it's a correct describe in document for
'wal_buffers_full'.
Where should I rewrite the description? If my understanding is not
correct, please let me know.
4. Quite strange to collect twice in XLogInsertRecord() for
xl_tot_len,
m_wal_records, m_wal_fpi.
Yes, Amit-san pointed me that too.
I'll remove them from pg_stat_wal since pg_stat_statements and vacuum
log
already shows the related statistics and there is a comment it's enough.
Anyway, if you need to the accumulated above statistics in pg_stat_wal,
please let me know.
5. I notice some code in issue_xlog_fsync() function to collect sync
info,
a standby may call the issue_xlog_fsync() too, which do not want to
to collect this info. I think this need some change avoid run by
standby
side.
Thanks, I will fix it.
Regards,
--
Masahiro Ikeda
NTT DATA CORPORATION
