| set hive.mapred.mode=nonstrict; |
| set hive.stats.autogather=false; |
| set hive.optimize.union.remove=true; |
| |
| set hive.merge.mapfiles=false; |
| set hive.merge.mapredfiles=false; |
| |
| set hive.exec.dynamic.partition=true; |
| |
| -- SORT_QUERY_RESULTS |
| -- This is to test the union->selectstar->filesink optimization |
| -- Union of 2 map-reduce subqueries is performed followed by select star and a file sink |
| -- and the results are written to a table using dynamic partitions. |
| -- There is no need to write the temporary results of the sub-queries, and then read them |
| -- again to process the union. The union can be removed completely. |
| -- It does not matter, whether the output is merged or not. In this case, merging is turned |
| -- off |
| -- This tests demonstrates that this optimization works in the presence of dynamic partitions. |
| |
| -- Since this test creates sub-directories for the output table outputTbl1_n25, it might be easier |
| -- to run the test only on hadoop 23 |
| |
| create table inputTbl1_n18(key string, val string) stored as textfile; |
| create table outputTbl1_n25(key string, `values` bigint) partitioned by (ds string) stored as rcfile; |
| |
| load data local inpath '../../data/files/T1.txt' into table inputTbl1_n18; |
| |
| explain |
| insert overwrite table outputTbl1_n25 partition (ds) |
| SELECT * |
| FROM ( |
| SELECT key, count(1) as `values`, '1' as ds from inputTbl1_n18 group by key |
| UNION ALL |
| SELECT key, count(1) as `values`, '2' as ds from inputTbl1_n18 group by key |
| ) a; |
| |
| insert overwrite table outputTbl1_n25 partition (ds) |
| SELECT * |
| FROM ( |
| SELECT key, count(1) as `values`, '1' as ds from inputTbl1_n18 group by key |
| UNION ALL |
| SELECT key, count(1) as `values`, '2' as ds from inputTbl1_n18 group by key |
| ) a; |
| |
| desc formatted outputTbl1_n25; |
| |
| show partitions outputTbl1_n25; |
| |
| set hive.input.format=org.apache.hadoop.hive.ql.io.HiveInputFormat; |
| select * from outputTbl1_n25 where ds = '1'; |
| select * from outputTbl1_n25 where ds = '2'; |