Re: advancing snapshot's xmin

"Tom Lane" <tgl@sss.pgh.pa.us> writes:

>> Consider a data loading job which has millions of INSERT statements in a file.
>> Currently if you put them all in a transaction it takes a single snapshot and
>> runs them all with the same snapshot.
>
>> If you reset xmin whenever you have no live snapshots then that job would be
>> doing that between every INSERT statement.
>
> These statements are 100% nonsense.

Uhm, yeah, I somehow didn't write was I was thinking. I didn't mean to say we
would be taking a new snapshot for each INSERT but that we would be resetting
xmin for each INSERT. Whereas currently we only set xmin once when we set the
serializable snapshot.

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