示例

• LOGICAL：

  CREATE TABLE testTable (regionkey int, name varchar);EXPLAIN SELECT regionkey, count(*) FROM testTable GROUP BY 1;                                                             Query Plan                                                              ------------------------------------------------------------------------------------------------------------------------------------- Output[regionkey, _col1]                                                                                                             │   Layout: [regionkey:integer, count:bigint]                                                                                        │   Estimates: {rows: ? (?), cpu: ?, memory: ?, network: ?}                                                                          │   _col1 := count                                                                                                                   └─ RemoteExchange[GATHER]                                                                                                               │   Layout: [regionkey:integer, count:bigint]                                                                                        │   Estimates: {rows: ? (?), cpu: ?, memory: ?, network: ?}                                                                          └─ Project[]                                                                                                                            │   Layout: [regionkey:integer, count:bigint]                                                                                        │   Estimates: {rows: ? (?), cpu: ?, memory: ?, network: ?}                                                                          └─ Aggregate(FINAL)[regionkey][$hashvalue]                                                                                              │   Layout: [regionkey:integer, $hashvalue:bigint, count:bigint]                                                                     │   Estimates: {rows: ? (?), cpu: ?, memory: ?, network: ?}                                                                          │   count := count("count_8")                                                                                                        └─ LocalExchange[HASH][$hashvalue] ("regionkey")                                                                                        │   Layout: [regionkey:integer, count_8:bigint, $hashvalue:bigint]                                                                   │   Estimates: {rows: ? (?), cpu: ?, memory: ?, network: ?}                                                                          └─ RemoteExchange[REPARTITION][$hashvalue_9]                                                                                            │   Layout: [regionkey:integer, count_8:bigint, $hashvalue_9:bigint]                                                                 │   Estimates: {rows: ? (?), cpu: ?, memory: ?, network: ?}                                                                          └─ Aggregate(PARTIAL)[regionkey][$hashvalue_10]                                                                                         │   Layout: [regionkey:integer, $hashvalue_10:bigint, count_8:bigint]                                                                │   count_8 := count(*)                                                                                                              └─ ScanProject[table = hive:default:testtable]                                                                                              Layout: [regionkey:integer, $hashvalue_10:bigint]                                                                                    Estimates: {rows: 0 (0B), cpu: 0, memory: 0B, network: 0B}/{rows: 0 (0B), cpu: 0, memory: 0B, network: 0B}                           $hashvalue_10 := "combine_hash"(bigint '0', COALESCE("$operator$hash_code"("regionkey"), 0))                                         regionkey := regionkey:int:0:REGULAR

• DISTRIBUTED：

  EXPLAIN (type DISTRIBUTED) SELECT regionkey, count(*) FROM testTable GROUP BY 1;                                                      Query Plan                                                       ----------------------------------------------------------------------------------------------------------------------- Fragment 0 [SINGLE]                                                                                                        Output layout: [regionkey, count]                                                                                      Output partitioning: SINGLE []                                                                                         Stage Execution Strategy: UNGROUPED_EXECUTION                                                                          Output[regionkey, _col1]                                                                                               │   Layout: [regionkey:integer, count:bigint]                                                                          │   Estimates: {rows: ? (?), cpu: ?, memory: ?, network: ?}                                                            │   _col1 := count                                                                                                     └─ RemoteSource[1]                                                                                                            Layout: [regionkey:integer, count:bigint]                                                                   Fragment 1 [HASH]                                                                                                          Output layout: [regionkey, count]                                                                                      Output partitioning: SINGLE []                                                                                         Stage Execution Strategy: UNGROUPED_EXECUTION                                                                          Project[]                                                                                                              │   Layout: [regionkey:integer, count:bigint]                                                                          │   Estimates: {rows: ? (?), cpu: ?, memory: ?, network: ?}                                                            └─ Aggregate(FINAL)[regionkey][$hashvalue]                                                                                │   Layout: [regionkey:integer, $hashvalue:bigint, count:bigint]                                                       │   Estimates: {rows: ? (?), cpu: ?, memory: ?, network: ?}                                                            │   count := count("count_8")                                                                                          └─ LocalExchange[HASH][$hashvalue] ("regionkey")                                                                          │   Layout: [regionkey:integer, count_8:bigint, $hashvalue:bigint]                                                     │   Estimates: {rows: ? (?), cpu: ?, memory: ?, network: ?}                                                            └─ RemoteSource[2]                                                                                                            Layout: [regionkey:integer, count_8:bigint, $hashvalue_9:bigint]                                      Fragment 2 [SOURCE]                                                                                                        Output layout: [regionkey, count_8, $hashvalue_10]                                                                     Output partitioning: HASH [regionkey][$hashvalue_10]                                                                   Stage Execution Strategy: UNGROUPED_EXECUTION                                                                          Aggregate(PARTIAL)[regionkey][$hashvalue_10]                                                                           │   Layout: [regionkey:integer, $hashvalue_10:bigint, count_8:bigint]                                                  │   count_8 := count(*)                                                                                                └─ ScanProject[table = hive:default:testtable, grouped = false]                                                               Layout: [regionkey:integer, $hashvalue_10:bigint]                                                                      Estimates: {rows: 0 (0B), cpu: 0, memory: 0B, network: 0B}/{rows: 0 (0B), cpu: 0, memory: 0B, network: 0B}             $hashvalue_10 := "combine_hash"(bigint '0', COALESCE("$operator$hash_code"("regionkey"), 0))                           regionkey := regionkey:int:0:REGULAR 

• VALIDATE：

  EXPLAIN (TYPE VALIDATE) SELECT id, count(*) FROM testTable GROUP BY 1; Valid------- true

• IO：

  EXPLAIN (TYPE IO, FORMAT JSON) SELECT regionkey , count(*) FROM testTable GROUP BY 1;           Query Plan            --------------------------------- {                                  "inputTableColumnInfos" : [ {      "table" : {                        "catalog" : "hive",              "schemaTable" : {                  "schema" : "default",            "table" : "testtable"          }                              },                               "columnConstraints" : [ ]      } ]                            } 

• COST：

  EXPLAIN (TYPE COST, FORMAT JSON) SELECT regionkey , count(*) FROM testTable GROUP BY 1;         Query Plan          ----------------------------- "Aggregated": {                 "CPU Time": 0.0              "MaxMemory": 0.0             "outputRows": 0.0            "outputSize(bytes)": 0.0  }    (1 row)