>It's an interesting idea.
>While it’s impossible to predict exactly how much WAL we’ll need to backtrack through --
>I assume it mainly depends on the duration of long-running transactions -- this approach
>seems to offer an opportunity using pg_rewind without enabling wal_log_hints.
Hi Neil, thanks and I think it's meaningful.
>Given the potential large gap between transaction IDs (especially when long-running transactions are involved),
>maintaining a list/bitmap struct would be worthwhile.
Yes I intend todo that but bitmapset can not use in src/bin and it seem no necessary to implement
one. And attention that min and max is what commited after diverge record, so it nomally small gap.
So it's the reason I give up.
>A minor suggestion, for an operation that may fail, I suggest retrieving the first XLOG_RUNNING_XACTS record to obtain
itsbase_xid
>before doing the deep-dig process. If the task cannot be completed (i.e., the base_xid <= min_commited_xid condition
isn’tmet),
>we can throw an error immediately instead of waiting for all WAL records to be parsed.
Mainly we can not get the first wal segment, because if no enough wal it will fetch wal segment
by restore_command. Your suggestion is meanful only if no restore_command. Anyway let's see
hacker's opnions.
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Best Regards,
Movead Li
