Re: unlogged tables vs. GIST

Heikki Linnakangas <heikki(dot)linnakangas(at)enterprisedb(dot)com> writes:
> On 17.12.2010 21:07, Tom Lane wrote:
>> IIUC, the problem is that the bufmgr might think that a GIST NSN is an
>> LSN that should affect when to force out a dirty buffer? What if we
>> taught it the difference? We could for example dedicate a pd_flags
>> bit to marking pages whose pd_lsn isn't actually an LSN.

> I'm not very fond of expanding buffer manager's knowledge of the page
> layout. How about a new flag in the buffer desc, BM_UNLOGGED?

That could work too, if you can explain how the flag comes to be set
without a bunch of ugliness all over the system. I don't want callers
of ReadBuffer to have to supply the bit for example.

regards, tom lane