On Mon, Mar 10, 2008 at 02:01:16AM +0000, Ying Zhang wrote:
> Update of /cvsroot/monetdb/pathfinder/runtime
> In directory sc8-pr-cvs16.sourceforge.net:/tmp/cvs-serv3350
>
> Modified Files:
> Tag: xquery-decomposition
> xrpc_client.mx
> Log Message:
> - adopt Stefan's tips: used rangesplit to split item|kind per container
> (Thanks!).
>
> - a lot of corrections to get this thing working
>
>
>
> Index: xrpc_client.mx
> ===================================================================
> RCS file: /cvsroot/monetdb/pathfinder/runtime/xrpc_client.mx,v
> retrieving revision 1.41.2.8
> retrieving revision 1.41.2.9
> diff -u -d -r1.41.2.8 -r1.41.2.9
> --- xrpc_client.mx 8 Mar 2008 21:17:27 -0000 1.41.2.8
> +++ xrpc_client.mx 10 Mar 2008 02:01:13 -0000 1.41.2.9
> @@ -94,94 +94,40 @@
> BAT[void, dbl] dbl_values,
> BAT[void, dbl] dec_values,
> BAT[void, str] str_values) : oid {
> -
> var maxnconts := ws.fetch(0).count();
> # split used_<item|kind> into multiple BATs according to their container
> IDs
vvvvvvvvv
> var uitems := bat(oid, bat, maxnconts); # container ID in head
> var ukinds := bat(oid, bat, maxnconts);
^^^^^^^^^
These two BATs are IMHO overwritten below (see "vvvvvvvvv"/"^^^^^^^^^");
hence, no (more) need to make them, here!??
> - var conts := used_kind.[int]().[>>](6).tsort(); # [oid,int]: container
> IDs in tail
> - var nconts := conts.tunique().count();
> - if(nconts = 1){ # all items are from the same container
> - uitems.insert(conts.fetch(0).oid(), used_item);
> - ukinds.insert(conts.fetch(0).oid(), used_kind);
> - } else {
> - # sort used_<item|kind> on container ID
> - var itemcont :=
> used_item.reverse().join(conts).reverse().tmark([EMAIL PROTECTED]);
> - var kindcont :=
> used_kind.reverse().join(conts).reverse().tmark([EMAIL PROTECTED]);
> -
> - var curcont := conts.fetch(0);
> - var tmpitem := bat(void, oid).seqbase([EMAIL PROTECTED]);
> - var tmpkind := bat(void, int).seqbase([EMAIL PROTECTED]);
> -
> - conts := conts.tmark([EMAIL PROTECTED]); # conts[void,int]
> - [EMAIL PROTECTED](){
> - # start of next container, save items|kinds of previous container
> - if($t != curcont) {
> - curcont := $t;
> - uitems.insert(curcont, tmpitem);
> - ukinds.insert(curcont, tmpkind);
> - tmpitem := bat(void, oid).seqbase([EMAIL PROTECTED]);
> - tmpkind := bat(void, int).seqbase([EMAIL PROTECTED]);
> - }
> -
> - tmpitem.append(itemcont.fetch($h));
> - tmpkind.append(kindcont.fetch($h));
> - }
> - uitems.insert(curcont, tmpitem);
> - ukinds.insert(curcont, tmpkind);
> - }
> + var conts := get_container([int](used_kind)); # [oid,int]: container IDs
> in tail
> + var unq_conts := tunique(conts).hmark([EMAIL PROTECTED]);
> + var nconts := count(unq_conts);
> + var rs := rangesplit(conts, nconts).tmark([EMAIL
> PROTECTED]).reverse().join(unq_conts).reverse();
This will do want you want (have rs's head contain the conts from the BATs
in its tail) ONLY if tunique(conts) & rangesplit(conts, nconts) happen to
produce the same order!
To be sure, you'd need to sort the unq_conts before marking them (result of
rangesplit shoiuld hopefully be sorted):
var unq_conts := tunique(conts).sort().hmark([EMAIL PROTECTED]);
Was there something wrong with my proposal:
var rs := rangesplit(conts, nconts);
rs := rs.reverse().mirror().[fetch](0).reverse();
?
vvvvvvvvv
> + uitems := rs.[mirror]().[leftfetchjoin](const used_item);
> + uitems := [tmark](uitems, const [EMAIL PROTECTED]);
> + ukinds := rs.[mirror]().[leftfetchjoin](const used_kind);
> + ukinds := [tmark](ukinds, const [EMAIL PROTECTED]);
^^^^^^^^^
(see "vvvvvvvvv"/^^^^^^^^^" above)
Plus: It might be more efficient to get rid of the head before the join,
since you "overwrite" them afterwards, anyway; i.e.:
uitems := rs.[tmark](oid(nil)).[leftfetchjoin](const
used_item).[tmark](uitems, const [EMAIL PROTECTED]);
>
> # split returned_<item|kind> into multiple BATs according to their
> container IDs
vvvvvvvvv
> var ritems := bat(oid, bat, maxnconts); # container ID in head
> var rkinds := bat(oid, bat, maxnconts);
^^^^^^^^^
Same as with uitems/ukinds above.
> - conts := returned_kind.[int]().[>>](6).tsort(); # [oid,int]: container
> IDs in tail
> - nconts := conts.tunique().count();
> - if(nconts = 1){ # all items are from the same container
> - ritems.insert(conts.fetch(0).oid(), returned_item);
> - rkinds.insert(conts.fetch(0).oid(), returned_kind);
> - } else {
> - # sort used_<item|kind> on container ID
> - var itemcont :=
> returned_item.reverse().join(conts).reverse().tmark([EMAIL PROTECTED]);
> - var kindcont :=
> returned_kind.reverse().join(conts).reverse().tmark([EMAIL PROTECTED]);
> -
> - var curcont := conts.fetch(0);
> - var tmpitem := bat(void, oid).seqbase([EMAIL PROTECTED]);
> - var tmpkind := bat(void, int).seqbase([EMAIL PROTECTED]);
> -
> - conts := conts.tmark([EMAIL PROTECTED]); # conts[void,int]
> - [EMAIL PROTECTED](){
> - # start of next container, save items|kinds of previous container
> - if($t != curcont) {
> - curcont := $t;
> - ritems.insert(curcont, tmpitem);
> - rkinds.insert(curcont, tmpkind);
> - tmpitem := bat(void, oid).seqbase([EMAIL PROTECTED]);
> - tmpkind := bat(void, int).seqbase([EMAIL PROTECTED]);
> - }
> -
> - tmpitem.append(itemcont.fetch($h));
> - tmpkind.append(kindcont.fetch($h));
> - }
> - ritems.insert(curcont, tmpitem);
> - rkinds.insert(curcont, tmpkind);
> - }
> + conts := get_container([int](returned_kind)); # [oid,int]: container IDs
> in tail
> + unq_conts := tunique(conts).hmark([EMAIL PROTECTED]);
> + nconts := count(unq_conts);
> + rs := rangesplit(conts, nconts).tmark([EMAIL
> PROTECTED]).reverse().join(unq_conts).reverse();
(see above)
vvvvvvvvv
> + ritems := rs.[mirror]().[leftfetchjoin](const returned_item);
> + ritems := [tmark](ritems, const [EMAIL PROTECTED]);
> + rkinds := rs.[mirror]().[leftfetchjoin](const returned_kind);
> + rkinds := [tmark](rkinds, const [EMAIL PROTECTED]);
^^^^^^^^^
(see above)
>
> # align uitems|kinds and ritems|kinds,
> # fill missing container with emtpybat
> var emptybat := bat(void,void,0);
> - [EMAIL PROTECTED](){
> - var err := CATCH({ritems.find($h);});
> - if(err.search("not found") >= 0){
> - ritems.insert($h, emptybat);
> - }
> - }
> - [EMAIL PROTECTED](){
> - var err := CATCH({uitems.find($h);});
> - if(err.search("not found") >= 0){
> - uitems.insert($h, emptybat);
> - }
> - }
> -
> + var usedonly := kdiff(uitems,ritems).project(emptybat);
> + ritems.access(BAT_WRITE).insert(usedonly);
> + rkinds.access(BAT_WRITE).insert(usedonly);
> + var returnedonly := kdiff(ritems,uitems).project(emptybat);
> + uitems.access(BAT_WRITE).insert(returnedonly);
> + ukinds.access(BAT_WRITE).insert(returnedonly);
a) Do you need to modify these BATs later on?
If not, you might want the set them read-only, again, after the insert:
ritems.access(BAT_WRITE).insert(usedonly).access(BAT_READ);
b) To be sure that your variables till point to the correct BATs
(access(BAT_WRITE) *might* return a copy!), you should asign the result:
ritems := ritems.access(BAT_WRITE).insert(usedonly)[.access(BAT_READ)];
Stefan
--
| Dr. Stefan Manegold | mailto:[EMAIL PROTECTED] |
| CWI, P.O.Box 94079 | http://www.cwi.nl/~manegold/ |
| 1090 GB Amsterdam | Tel.: +31 (20) 592-4212 |
| The Netherlands | Fax : +31 (20) 592-4312 |
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