There is a slide introducing how Kylin works. http://www.slideshare.net/XuJiang2/kylin-hadoop-olap-engine
2016-09-08 12:20 GMT+08:00 Something Something <[email protected]>: > It worked. Thanks. It's pretty fast as well. > > So now if you can explain how Kylin runs this in the background that would > be great -:) What I mean is - in this query I am grouping by: > > group by part_dt, kylin_sales.LEAF_CATEG_ID, LSTG_FORMAT_NAME, > LSTG_SITE_ID, META_CATEG_NAME > > Has Kylin already pre-built a "5 dimensional" array with all aggregates > such as sum(price), max(price) etc? > > OR - > > Does it build HBase table as follows? > > Key: (Dim1, Dim2..... DimN). > Value: Array of all aggregations (SUM, MAX etc) > > & when a query is triggered combines the Dimensions that are not > specified? Or some other way? > > Just want to understand how it behaves internally. Thanks. > > > > > On Wed, Sep 7, 2016 at 8:11 AM, ShaoFeng Shi <[email protected]> > wrote: > >> DEFAULT is a reserved keyword in Apache Calcite (which acts as Kylin's >> SQL parser) ; when use it in SQL, please add double quote ("DEFAULT") to >> escape; >> >> 2016-09-07 13:17 GMT+08:00 Something Something <[email protected]> >> : >> >>> Here's a query that works in Hive, but gives a syntax error in Kylin. >>> Any idea why? >>> >>> select part_dt, kylin_sales.LEAF_CATEG_ID, LSTG_FORMAT_NAME, >>> LSTG_SITE_ID, META_CATEG_NAME, sum(price), max(price), min(price) from >>> kylin_sales INNER JOIN DEFAULT.KYLIN_CATEGORY_GROUPINGS as >>> KYLIN_CATEGORY_GROUPINGS ON KYLIN_SALES.LEAF_CATEG_ID = >>> KYLIN_CATEGORY_GROUPINGS.LEAF_CATEG_ID AND KYLIN_SALES.LSTG_SITE_ID = >>> KYLIN_CATEGORY_GROUPINGS.SITE_ID group by part_dt, >>> kylin_sales.LEAF_CATEG_ID, LSTG_FORMAT_NAME, LSTG_SITE_ID, META_CATEG_NAME >>> order by part_dt, kylin_sales.LEAF_CATEG_ID, LSTG_FORMAT_NAME, >>> LSTG_SITE_ID, META_CATEG_NAME; >>> >>> >>> Error message: >>> >>> Encountered "DEFAULT" at line 1, column 156. Was expecting one of: >>> <IDENTIFIER> ... <QUOTED_IDENTIFIER> ... <BACK_QUOTED_IDENTIFIER> ... >>> <BRACKET_QUOTED_IDENTIFIER> ... <UNICODE_QUOTED_IDENTIFIER> ... "LATERAL" >>> ... "(" ... "UNNEST" ... "TABLE" ... >>> >> >> >> >> -- >> Best regards, >> >> Shaofeng Shi >> >> > -- With Warm regards Yiming Liu (刘一鸣)
