Re: Creating Index and no performance improvements

2016-10-27 Thread Hilmi Egemen Ciritoğlu
thank you for your answer by the way this is explain commands out: EXPLAIN select AVG(dryBulbTempF) FROM testindex WHERE ndate = '20070710'; OK STAGE DEPENDENCIES: Stage-1 is a root stage Stage-0 depends on stages: Stage-1 STAGE PLANS: Stage: Stage-1 Map Reduce Map Operator Tree:

Re: Creating Index and no performance improvements

2016-10-27 Thread Mich Talebzadeh
Long answer An EXTERNAL TABLE in hive is a stub for table in Hive metastore. Data is not managed by Hive and it is an HDFS concern. For that reason if you drop an EXTERNAL table in Hive you just drop references for that table in Hive metastore. Data is not deleted. The conventional indexes don'

Re: Creating Index and no performance improvements

2016-10-27 Thread Mich Talebzadeh
Have you checked running SQL with EXPLAIN EXTENDED SELECT .. And post the results. In general your compact index will not work HTH Dr Mich Talebzadeh LinkedIn * https://www.linkedin.com/profile/view?id=AAEWh2gBxianrbJd6zP6AcPCCdOABUrV8Pw

Creating Index and no performance improvements

2016-10-27 Thread Hilmi Egemen Ciritoğlu
Hi guys, I created table and index on this table. Also after I alter that index with rebuild option. But still can't see performance improvements. Only, I can see performance improvements when I query to index table. I used following commands : CREATE EXTERNAL TABLE testindex(wban INT, ndate ST