visibility maps

<br />    /*<br />     * We don't need to lock the page, as we're only looking at a single bit.<br />     */<br />   
result= (map[mapByte] & (1 << mapBit)) ? true : false;<br /><br /><br /> Isn't this a dangerous assumption to
make? I am not so sure that even a bit can be read atomically on all platforms. I think the only caller of
visibilitymap_test()is VACUUM which can live with a false information. But if this is indeed a problem, should we
eitherfix this or have explicit comments there ?<br clear="all" /><br />BTW, my apologies for random comments. I
haven'tfollowed the discussion well, neither done a full review. So these things might have been discussed before.<br
/><br/> Thanks,<br />Pavan <br /><br />-- <br />Pavan Deolasee<br />EnterpriseDB     <a
href="http://www.enterprisedb.com">http://www.enterprisedb.com</a><br/>