Re: pg_stat_*_columns?

Robert Haas wrote:

> If we arranged things so that the processes could use the data in the
> DSM directly rather than having to copy it out, we'd presumably save
> quite a bit of memory, since the whole structure would be shared
> rather than each backend having its own copy.  But if the structure
> got too big to map (on a 32-bit system), then you'd be sort of hosed,
> because there's no way to attach just part of it.  That might not be
> worth worrying about, but it depends on how big it's likely to get - a
> 32-bit system is very likely to choke on a 1GB mapping, and maybe even
> on a much smaller one.

How realistic it is that you would get a 1 GB mapping on a 32-bit
system?  Each table entry is 106 bytes at the moment if my count is
right, so you need about one million tables to get that large a table.
It doesn't sound really realistic to have such a database on a smallish
machine.

-- 
Álvaro Herrera                http://www.2ndQuadrant.com/
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