Got the issue...
if the primary key type is not compatible with the predicate type ... it
turns into a scan.

Thanks Taewoo!

On Sun, Dec 3, 2017 at 4:08 PM, Taewoo Kim <[email protected]> wrote:

> From Line 531
> https://github.com/apache/asterixdb/blob/master/
> asterixdb/asterix-algebra/src/main/java/org/apache/asterix/
> optimizer/rules/am/BTreeAccessMethod.java
>
>
> Best,
> Taewoo
>
> On Sun, Dec 3, 2017 at 4:05 PM, Taewoo Kim <[email protected]> wrote:
>
> > My understanding is that if a select condition can be covered by the
> > primary key (i.e., only contains the primary key condition and B+Tree can
> > be utilized), then only unnest-map should survive.
> >
> >
> > Best,
> > Taewoo
> >
> > On Sun, Dec 3, 2017 at 4:03 PM, Chen Luo <[email protected]> wrote:
> >
> >> I don't think it's the case...I tried on my local env, and it's using a
> >> primary index lookup instead of scan. Can you make sure the spelling of
> >> the
> >> primary key is correct?
> >>
> >> On Sun, Dec 3, 2017 at 3:49 PM, Wail Alkowaileet <[email protected]>
> >> wrote:
> >>
> >> > Hi Devs,
> >> >
> >> > *For the given query:*
> >> >
> >> > SELECT VALUE t.text
> >> > FROM ITweets as t
> >> > WHERE t.tid = 100
> >> >
> >> > *The optimized plan:*
> >> >
> >> > distribute result [$$6]
> >> > -- DISTRIBUTE_RESULT  |PARTITIONED|
> >> >   exchange
> >> >   -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
> >> >     project ([$$6])
> >> >     -- STREAM_PROJECT  |PARTITIONED|
> >> >       assign [$$6] <- [$$t.getField("text")]
> >> >       -- ASSIGN  |PARTITIONED|
> >> >         project ([$$t])
> >> >         -- STREAM_PROJECT  |PARTITIONED|
> >> >           select (eq($$7, 100))
> >> >           -- STREAM_SELECT  |PARTITIONED|
> >> >             exchange
> >> >             -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
> >> >               data-scan []<-[$$7, $$t] <- FlatDataverse.ITweets
> >> >               -- DATASOURCE_SCAN  |PARTITIONED|
> >> >                 exchange
> >> >                 -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
> >> >                   empty-tuple-source
> >> >                   -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
> >> >
> >> > Do we always do a scan and then filter the result, even though the
> query
> >> > predicate is on the primary key?
> >> > --
> >> >
> >> > *Regards,*
> >> > Wail Alkowaileet
> >> >
> >>
> >
> >
>



-- 

*Regards,*
Wail Alkowaileet

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