Re: GiST VACUUM

> 21 марта 2019 г., в 2:30, Heikki Linnakangas <hlinnaka@iki.fi> написал(а):
> one remaining issue that needs to be fixed:
>
> During Hot Standby, the B-tree code writes a WAL reord, when a deleted
> page is recycled, to prevent the deletion from being replayed too early
> in the hot standby. See _bt_getbuf() and btree_xlog_reuse_page(). I
> think we need to do something similar in GiST.
>
> I'll try fixing that tomorrow, unless you beat me to it. Making the
> changes is pretty straightforward, but it's a bit cumbersome to test.

I've tried to deal with it and stuck... I think we should make B-tree WAL record for this shared, remove BlockNumber
andother unused stuff, leaving just xid and db oid. 
And reuse this record for B-tree, GiST and GIN (yeah, it is not checking for that conflict).

Though, I'm not sure it is important for GIN. Scariest thing that can happen: it will return same tid twice. But it is
doingbitmap scan, you cannot return same bit twice... 

Eventually, hash, spgist and others will have same thing too.

Best regards, Andrey Borodin.