| set hive.mapred.mode=nonstrict; |
| set hive.stats.autogather=false; |
| set hive.optimize.union.remove=true; |
| |
| set hive.merge.mapfiles=true; |
| set hive.merge.mapredfiles=true; |
| set hive.merge.smallfiles.avgsize=1; |
| |
| -- SORT_QUERY_RESULTS |
| -- This is to test the union->selectstar->filesink optimization |
| -- Union of 3 subqueries is performed (exactly one of which requires a map-reduce job) |
| -- followed by select star and a file sink. |
| -- 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 |
| -- on |
| |
| -- Since this test creates sub-directories for the output table outputTbl1_n6, it might be easier |
| -- to run the test only on hadoop 23 |
| |
| create table inputTbl1_n4(key string, val string) stored as textfile; |
| create table outputTbl1_n6(key string, `values` bigint) stored as textfile; |
| |
| load data local inpath '../../data/files/T1.txt' into table inputTbl1_n4; |
| |
| explain |
| insert overwrite table outputTbl1_n6 |
| SELECT * |
| FROM ( |
| SELECT key, count(1) as `values` from inputTbl1_n4 group by key |
| UNION ALL |
| SELECT key, 1 as `values` from inputTbl1_n4 |
| UNION ALL |
| SELECT key, 2 as `values` from inputTbl1_n4 |
| ) a; |
| |
| insert overwrite table outputTbl1_n6 |
| SELECT * |
| FROM ( |
| SELECT key, count(1) as `values` from inputTbl1_n4 group by key |
| UNION ALL |
| SELECT key, 1 as `values` from inputTbl1_n4 |
| UNION ALL |
| SELECT key, 2 as `values` from inputTbl1_n4 |
| ) a; |
| |
| desc formatted outputTbl1_n6; |
| |
| set hive.input.format=org.apache.hadoop.hive.ql.io.HiveInputFormat; |
| select * from outputTbl1_n6; |