this is the error message:
Flink SQL> (SELECT number_feature FROM map_string_string1) UNION (SELECT number_feature FROM map_string_string2); 2021-03-29 16:57:15,479 INFO org.apache.hadoop.hive.metastore.HiveMetaStoreClient [] - Trying to connect to metastore with URI thrift://localhost:9083 2021-03-29 16:57:15,483 INFO org.apache.hadoop.hive.metastore.HiveMetaStoreClient [] - Opened a connection to metastore, current connections: 2 2021-03-29 16:57:15,530 INFO org.apache.hadoop.hive.metastore.HiveMetaStoreClient [] - Connected to metastore. 2021-03-29 16:57:15,530 INFO org.apache.hadoop.hive.metastore.RetryingMetaStoreClient [] - RetryingMetaStoreClient proxy=class org.apache.hadoop.hive.metastore.HiveMetaStoreClient ugi=zhangying480 (auth:SIMPLE) retries=1 delay=1 lifetime=0 2021-03-29 16:57:15,580 INFO org.apache.hadoop.hive.metastore.HiveMetaStoreClient [] - Closed a connection to metastore, current connections: 1 2021-03-29 16:57:15,651 INFO org.apache.hadoop.hive.metastore.HiveMetaStoreClient [] - Trying to connect to metastore with URI thrift://localhost:9083 2021-03-29 16:57:15,652 INFO org.apache.hadoop.hive.metastore.HiveMetaStoreClient [] - Opened a connection to metastore, current connections: 2 2021-03-29 16:57:15,652 INFO org.apache.hadoop.hive.metastore.HiveMetaStoreClient [] - Connected to metastore. 2021-03-29 16:57:15,652 INFO org.apache.hadoop.hive.metastore.RetryingMetaStoreClient [] - RetryingMetaStoreClient proxy=class org.apache.hadoop.hive.metastore.HiveMetaStoreClient ugi=zhangying480 (auth:SIMPLE) retries=1 delay=1 lifetime=0 2021-03-29 16:57:15,698 INFO org.apache.hadoop.hive.metastore.HiveMetaStoreClient [] - Closed a connection to metastore, current connections: 1 [ERROR] Could not execute SQL statement. Reason: java.lang.UnsupportedOperationException: Unsupported type: MAP<STRING, STRING> I meet a problem just like this: My flink version is 1.12.0，and I change the version to 1.12.3, the problem still exist. I create two tables which have data type map, I want to union two tables to one, but when i run on sql-client, I met such a problem:(number_feature is a map data) but when I run this sql,it has correct result:"(SELECT query FROM map_string_string1) UNION (SELECT query FROM map_string_string2)" The reason why it cannot support map union is a problem? this is my create table statements: CREATE TABLE `map_string_string1`( `query` string, `wid` string, `index` int, `page` string, `hc_cid1` string, `hc_cid2` string, `hc_cid3` string, `cid1` string, `cid2` string, `cid3` string, `ts` bigint, `number_feature` map<string,string>) PARTITIONED BY ( `dt` string) ROW FORMAT DELIMITED FIELDS TERMINATED BY '\t' LINES TERMINATED BY '\n' STORED AS INPUTFORMAT 'org.apache.hadoop.hive.ql.io.orc.OrcInputFormat' OUTPUTFORMAT 'org.apache.hadoop.hive.ql.io.orc.OrcOutputFormat' CREATE TABLE `map_string_string2`( `query` string, `wid` string, `index` int, `page` string, `hc_cid1` string, `hc_cid2` string, `hc_cid3` string, `cid1` string, `cid2` string, `cid3` string, `ts` bigint, `number_feature` map<string,string>) PARTITIONED BY ( `dt` string) ROW FORMAT DELIMITED FIELDS TERMINATED BY '\t' LINES TERMINATED BY '\n' STORED AS INPUTFORMAT 'org.apache.hadoop.hive.ql.io.orc.OrcInputFormat' OUTPUTFORMAT 'org.apache.hadoop.hive.ql.io.orc.OrcOutputFormat'
