Re: Online enabling of checksums

Hi,

On 2018-02-24 03:07:28 +0100, Tomas Vondra wrote:
> I agree having to restart the whole operation after a crash is not
> ideal, but I don't see how adding a flag actually solves it. The problem
> is the large databases often store most of the data (>80%) in one or two
> central tables (think fact tables in star schema, etc.). So if you
> crash, it's likely half-way while processing this table, so the whole
> table would still have relchecksums=false and would have to be processed
> from scratch.

I don't think it's quite as large a problem as you make it out to
be. Even in those cases you'll usually have indexes, toast tables and so
forth.

> But perhaps you meant something like "position" instead of just a simple
> true/false flag?

I think that'd incur a much larger complexity cost.

Greetings,

Andres Freund