| set hive.mapred.mode=nonstrict; |
| set hive.optimize.skewjoin.compiletime = true; |
| |
| CREATE TABLE T1_n27(key STRING, val STRING) |
| SKEWED BY (key, val) ON ((2, 12)) STORED AS TEXTFILE; |
| |
| LOAD DATA LOCAL INPATH '../../data/files/T1.txt' INTO TABLE T1_n27; |
| |
| CREATE TABLE T2_n18(key STRING, val STRING) |
| SKEWED BY (key) ON ((2)) STORED AS TEXTFILE; |
| |
| LOAD DATA LOCAL INPATH '../../data/files/T2.txt' INTO TABLE T2_n18; |
| |
| -- One of the tables is skewed by 2 columns, and the other table is |
| -- skewed by one column. Ths join is performed on the first skewed column |
| -- The skewed value for the jon key is common to both the tables. |
| -- In this case, the skewed join value is not repeated in the filter. |
| -- adding a order by at the end to make the results deterministic |
| |
| EXPLAIN |
| SELECT a.*, b.* FROM T1_n27 a JOIN T2_n18 b ON a.key = b.key; |
| |
| SELECT a.*, b.* FROM T1_n27 a JOIN T2_n18 b ON a.key = b.key |
| ORDER BY a.key, b.key, a.val, b.val; |
| |
| DROP TABLE T1_n27; |
| DROP TABLE T2_n18; |
| |
| |
| CREATE TABLE T1_n27(key STRING, val STRING) |
| SKEWED BY (key, val) ON ((2, 12)) STORED AS TEXTFILE; |
| |
| LOAD DATA LOCAL INPATH '../../data/files/T1.txt' INTO TABLE T1_n27; |
| |
| CREATE TABLE T2_n18(key STRING, val STRING) |
| SKEWED BY (key) ON ((2)) STORED AS TEXTFILE; |
| |
| LOAD DATA LOCAL INPATH '../../data/files/T2.txt' INTO TABLE T2_n18; |
| |
| -- One of the tables is skewed by 2 columns, and the other table is |
| -- skewed by one column. Ths join is performed on the both the columns |
| -- In this case, the skewed join value is repeated in the filter. |
| |
| EXPLAIN |
| SELECT a.*, b.* FROM T1_n27 a JOIN T2_n18 b ON a.key = b.key and a.val = b.val; |
| |
| SELECT a.*, b.* FROM T1_n27 a JOIN T2_n18 b ON a.key = b.key and a.val = b.val |
| ORDER BY a.key, b.key, a.val, b.val; |
