When you tried 2888, did you have pig.exec.mapPartAgg set to true, and pig.exec.mapPartAgg.minReduction set to a low value (2 or 3)?
You said you applied the patch -- what version are you currently running? Other approaches are also probabilistic so if you need exact counts, no dice.. I was thinking bloom filters or hyper log log. D On Fri, Sep 28, 2012 at 2:40 PM, Deepak Tiwari <[email protected]> wrote: > Hi Dmitriy > > I did try 2888 ( I checked out new from trunk and applied the patch ) and > unfortunately it was not making much difference for me. You have mentioned > other distinct counting approaches. Could you please give me more details > and any hints to implement those. > > Regards, > > Deepak. > > On Wed, Aug 29, 2012 at 1:05 PM, Deepak Tiwari <[email protected]> > wrote: > > > Thanks Dmitry. > > > > 1) yup. exact distinct counts are required, since it is finance > reporting. > > ( I actually had thought about bloom filter but since we need exact count > > it might not be applicable ) > > 2) Oh I think Pig 2888 recently filed, it didnt come in my search > > previously. Sure I will apply the patch and see if that makes any > > difference.. > > > > Thanks very much for responding.... > > > > > > > > On Tue, Aug 28, 2012 at 11:45 PM, Dmitriy Ryaboy <[email protected] > >wrote: > > > >> Couple of ideas: > >> > >> 1) do you need exact distinct counts? There are approximate distinct > >> counting approaches that may be appropriate an much more efficient. > >> 2) can you try with pig-2888? > >> > >> On Aug 28, 2012, at 1:35 PM, Deepak Tiwari <[email protected]> > wrote: > >> > >> > Hi, > >> > > >> > I am processing huge dataset and need to aggregate data using on > >> multiple > >> > levels ( columns ). > >> > > >> > for example A,B,C,D,E,F, CalculateDistinctinctOnValue1, > >> > CalculateDistinctinctOnValue2, Sum(value3) > >> > > >> > I have tried two approaches in one I am reading the file one time and > >> > generating groupby on each level > >> > > >> > for example group by (A,B), group by (A,B,C) > >> > > >> > Since I have to do distinct inside foreach which is taking too much > >> time, > >> > mostly because of skew. ( I have enabled multiquery) > >> > > >> > In another approach I have tried creating 8 separate scripts to > process > >> > each group by too, but that is taking more or less the same time and > >> not a > >> > very efficient one. Could someone please suggest any other way.. > >> > > >> > Thanks in advance. > >> > > >> > > >> > Deepak > >> > > > > >
