Dear Jacky, Yes I am planning to support both data format reader(new and old) + writer(new and old), default new writer will be enabled, but if user wants to write in older format for that i will expose one configuration. Please let me know if you have any other suggestion.
-Regards Kumar Vishal On Thu, Nov 3, 2016 at 8:24 PM, Jacky Li <jacky.li...@qq.com> wrote: > The proposed change is reasonable, +1. > But is there a plan to make the reader backward compatible with the old > format? So the impact to the current deployment is minimum. > > Regards, > Jacky > > > 在 2016年11月2日,上午12:38,Kumar Vishal <kumarvishal1...@gmail.com> 写道: > > > > Hi Xiaoqiao He, > > > > Please find the attachment. > > > > -Regards > > Kumar Vishal > > > > On Tue, Nov 1, 2016 at 9:27 PM, Xiaoqiao He <xq.he2...@gmail.com > <mailto:xq.he2...@gmail.com>> wrote: > > Hi Kumar Vishal, > > > > I couldn't get Fig. of the file format, could you re-upload them? > > Thanks. > > > > Best Regards > > > > On Tue, Nov 1, 2016 at 7:12 PM, Kumar Vishal <kumarvishal1...@gmail.com > <mailto:kumarvishal1...@gmail.com>> > > wrote: > > > > > > > > Hello All, > > > > > > Improving carbon first time query performance > > > > > > Reason: > > > 1. As file system cache is cleared file reading will make it slower to > > > read and cache > > > 2. In first time query carbon will have to read the footer from file > data > > > file to form the btree > > > 3. Carbon reading more footer data than its required(data chunk) > > > 4. There are lots of random seek is happening in carbon as column > > > data(data page, rle, inverted index) are not stored together. > > > > > > Solution: > > > 1. Improve block loading time. This can be done by removing data chunk > > > from blockletInfo and storing only offset and length of data chunk > > > 2. compress presence meta bitset stored for null values for measure > column > > > using snappy > > > 3. Store the metadata and data of a column together and read together > this > > > reduces random seek and improve IO > > > > > > For this I am planing to change the carbondata thrift format > > > > > > *Old format* > > > > > > > > > > > > *New format* > > > > > > > > > > > > ** > > > > > > Please vote and comment for this new format change > > > > > > -Regards > > > Kumar Vishal > > > > > > > > > > > > > > > >