On 9/25/07, Jan Wieck <JanWieck at yahoo.com> wrote:
> On 9/25/2007 5:51 AM, Marko Kreen wrote:
> > Only question that may need discussion is the question of naming.
> >
> > Current APi is following:
> >
> >  type: txid_snapshot
> >
> >  get_current_txid(): int8
> >  get_current_snapshot(): txid_snapshot
> >  get_snapshot_xmin(sn): int8
> >  get_snapshot_xmax(sn): int8
> >  get_snapshot_active(sn): setof int8
> >  txid_in_snapshot(int8, sn): bool
> >
> > But it seems kind of random, considering it is targeted to be core
> > functinality in the future.  I'd prefer something more concise:
> >
> >  type: snapshot
> >
> >  current_txid(): int8
> >  current_snapshot(): snapshot
> >  snapshot_xmin()
> >  snapshot_xmax()
> >  snapshot_uncommitted()  ??
> >  snapshot_contains()     ??
>
> Eventually all functions should have the txid_ prefix?

Ok, sounds reasonable too.

>    int8          txid_current()
>    txid_snapshot txid_current_snapshot()
>    int8          txid_snapshot_xmin(sn)
>    int8          txid_snapshot_xmax(sn)
>    setof int8    txid_snapshot_xip(sn)

Ok.

>    bool          txid_in_snapshot_xip(int8, sn)

Is it really a often used function?  Otherwise
txid_snapshot_xip() should be enough?

>    bool          txid_lt_snapshot(int8, sn)
>    bool          txid_le_snapshot(int8, sn)
>    bool          txid_ge_snapshot(int8, sn)
>    bool          txid_gt_snapshot(int8, sn)

Why so many variants?  Isn't one enough?

And I think that should be with clearer name like
txid_is_visible() or txid_is_committed().

> > Somewhat better but the last 2 functions are still dubious.
> > Do you have better names?
>
> xip means "transactions in progress", and is used that way inside the
> backend. So that should be clear enough.

Indeed, it's backend vocabulary.

-- 
marko