I agree with jihong.carbon need to have smart logic to decide On Wed, 28 Sep 2016 at 6:12 AM, Jihong Ma <jihong...@huawei.com> wrote:
> Ideally this should be an internal improvement, not necessarily exposing > it as an config option, Carbon should be able to smartly figure out if > leveraging index is beneficial or straightly going for a file scan (just as > Parquet). > > Regards. > > Jihong > > -----Original Message----- > From: Liang Big data [mailto:chenliang6...@gmail.com] > Sent: Tuesday, September 27, 2016 4:43 PM > To: dev@carbondata.incubator.apache.org > Subject: Re: [Discussion]: option to disable multi-layered index scan and > use full table scan > > Hi > > good suggestion! > Add one configurable option to disable index for no filter and small table > scenarios. > One comment : you are suggesting only disable MDK; How about other > index(inverted index,and MINMAX index)? > > +1 for this feature > > Regards > Liang > > 2016-09-28 6:49 GMT+08:00 Aniket Adnaik <aniket.adn...@gmail.com>: > > > Carbondata can provide some way to disable usage of multi-layered index > and > > provide full table scan. > > This may help in following cases; > > 1. Small tables occupying only few number of blocks are probably better > of > > using full table scan. > > 2. Queries with large number of projections with no filter may benefit > from > > using full table scan. > > 3. Testing different scenarios and comparing with multiple HDFS file > > formats > > that do not provide multi layer index will be easier. > > > > Also, Carbondata scan internally should be smart enough to detect this > > based > > on query, data size, etc. > > > > Any comments? > > > > > > > > > > -- > > View this message in context: http://apache-carbondata- > > mailing-list-archive.1130556.n5.nabble.com/Discussion- > > option-to-disable-multi-layered-index-scan-and-use- > > full-table-scan-tp1526.html > > Sent from the Apache CarbonData Mailing List archive mailing list archive > > at Nabble.com. > > > > > > -- > > Regards > Liang >
