Re: AS OF queries

From: legrand legrand <legrand_legrand(at)hotmail(dot)com>
To: pgsql-hackers(at)postgresql(dot)org
Subject: Re: AS OF queries
Date: 2018-01-10 21:20:03
Message-ID: 1515619203017-0.post@n3.nabble.com
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> Sorry, truncate is not compatible with AS OF. It is performed at file
> level and deletes old old version.
> So if you want to use time travel, you should not use truncate.

As time travel doesn't support truncate, I would prefer it to be checked.
If no check is performed, ASOF queries (with timestamp before truncate )
would return no data even when there was: this could be considered as a
wrong result.

if a truncate is detected, an error should be raised, saying data is no more
available before truncate timestamp.

> Does it mean that no explicit check is needed that table metadata was
> not checked after specified timeslice?

Not sure, it would depend on metadata modification type ...
adding/dropping a columns seems working,
what about altering a column type or dropping / recreating a table ?

Regards
PAscal

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