Hello,
probably you remember my crazy idea involving using indexes
directly in scans (and resulting speedup).
The idea was given to me by experiences with M$SQL (it is
yes another M$ soft but its planner is probably better
than pg's - no flames please).
Because I studied M$ again I've got another
Hello,
maybe I missed something, but in last days I was thinking how would I
write my own sql server. I got several ideas and because these are not
used in PG they are probably bad - but I can't figure why.
1) WAL
We have buffer manager, ok. So why not to use WAL as part of it and don't
log INSE
> This was brought up a week ago, and I consider it an interesting idea.
> The only problem is that we would no longer have control over which
> pages made it to disk. The OS would perhaps write pages as we modified
> them. Not sure how important that is.
Yes. As I work on linux kernel I know
> > Bruce Momjian <[EMAIL PROTECTED]> writes:
> > > The only problem is that we would no longer have control over which
> > > pages made it to disk. The OS would perhaps write pages as we modified
> > > them. Not sure how important that is.
> >
> > Unfortunately, this alone is a *fatal* objecti
> > BTW, what means "bummer" ?
>
> Sorry, it means, "Oh, I am disappointed."
thanks :)
> > But for many OSes you CAN control when to write data - you can mlock
> > individual pages.
>
> mlock() controls locking in physical memory. I don't see it controling
> write().
When you mmap, you don't
> > Pros: upper layers can think thet buffers are always safe/logged and
> > there is no special handling for indices; very simple/fast redo
> > Cons: can't implement undo - but in non-overwriting is not needed (?)
>
> But needed if we want to get rid of vacuum and have savepoints.
Hmm. Ho
> > When you mmap, you don't use write() ! mlock actualy locks page in
> > memory and as long as the page is locked the OS doesn't attempt to
> > store the dirty page. It is intended also for security app to
> > ensure that sensitive data are not written to unsecure storage
> > (hdd). It is defi
