> -----Original Message-----
> From: Mikheev, Vadim [mailto:vmikheev@SECTORBASE.COM]
>
> > > I'm going to handle btree split but currently there is no way
> > > to rollback it - we unlock splitted pages after parent
> > > is locked and concurrent backend may update one/both of
> > > siblings before we get our locks back.
> > > We have to continue with split or could leave parent unchanged
> > > and handle "my bits moved..." (ie continue split in another
> > > xaction if we found no parent for a page) ... or we could hold
> > > locks on all splitted pages till some parent updated without
> > > split, but I wouldn't do this.
> > >
> >
> > It seems to me that btree split operations must always be
> > rolled forward even in case of abort/crash. DO you have
> > other ideas ?
>
> Yes, it should, but hard to implement, especially for abort case.
> So, for the moment, I would proceed with handling "my bits moved...":
> no reason to elog(FATAL) here - we can try to insert missed pointers
> into parent page(s). WAL will guarantee that btitems moved to right
> sibling will not be lost (level consistency), and missing some pointers
> in parent level is acceptable - scans will work.
>
I looked into your XLOG stuff a little.
It seems that XLogFileOpen() isn't implemented yet.
Would/should XLogFIleOpen() guarantee to open a Relation
properly at any time ?
Regards.
Hiroshi Inoue
