[Monetdb-developers] Monetdb-developers Digest, Vol 5, Issue 6

Stefan Manegold Stefan.Manegold at cwi.nl
Fri Oct 6 16:34:14 CEST 2006

On Fri, Oct 06, 2006 at 04:16:05PM +0200, p.a.boncz wrote:
> Hi all,
> > In PROC rpc_client() (runtime/xrpc.mx), I had changed
> >	ws_addcoll(ws, ...
> > to
> > 	ws_opencoll(ws_id(ws), ...
> it should we ws_opencoll(wsid, ...)

It is wsid since this morning (see my respective checkins and earlier
follow-up on this thread).

> You have that, because in the query context we always have both variable
> 'ws' and 'wsid'.
> ws_id(ws) should be called once, it asks for a unique oid. The combination
> of (id,int(ws)) is squeezed into a lng, and that is wsid. 
> As for doc_tbl(), what would work is to change its parameter to wsid; one
> can always get the ws with ws := ws_bat(wsid), this is done now in numerous
> places in pf_support.mx. 

well, as said before, that's not that easy, since doc_tbl (and it's
brothers/sistens) follows and API definiton that aslo returns ws --- I have
not idea, how this works/is used in detail ... JanR?

> Your conclusions (1), (2) and (3) are all correct.
> But, Jan's suggestion to store the wsid inside the ws can also work.
> However, I deem it very awkward to introduce a new BAT in the ws just to
> retain a number. Other suggestions are to rename the ws-bat to some unique
> key, and then we can use that name as transaction key (=wsid). We would
> change the wsid type then from lng to str. Another idea is to set the
> head-seqbase of the ws-bat to an oid. I think the ws is accessed with
> fetch() only, which disregards any seqbase.

What about encoding/storing the wsid in the ws BAT's name?

I'll try do do that --- seems the smallest-impact solution that could
(should?) finally satisfy all sides --- I hope ... this discussion already
costs far too much time and energy ... |-(

Basically, call current interfaces can stay unchanged.

Only ws_id() will change slightly:

ws_id() checkes whether the ws BAT as already been renamed, i.e., assigend
an ID; if so, it uses that one; otherwise, it assigns one nd renames the ws
BAT accordingly.

Thus, ws_id can be called at any time on a ws BAT, and yield the same result
each time it's called on the same ws BAT.

> Note that internally in pathfinder.mx there are a number of functions that
> just pass around an artificial wsid, and in fact a ws does not exist at all
> (this is the MIL document management interface e.g. shred_doc), so a number
> of (internal) functions in pathfinder.mx will have to stay using a wsid in
> their signature. They do not need a ws-bat.
> But the exported functions ws_opencoll and ws_opendoc could indeed just use
> a ws as they did before.
> I will not have time for this until next week, so if anyone feels like
> adventurous, he may try.

(Hopefully as a final act on this saga), I'll try to implement the above
mentioned "solution" ...


> Peter

| Dr. Stefan Manegold | mailto:Stefan.Manegold at cwi.nl |
| CWI,  P.O.Box 94079 | http://www.cwi.nl/~manegold/  |
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