Tim,     We have solved this by the combined efforts of Cloudera Support, Microsoft Support, you and us.   GET_COLUMNS takes 4 arguments: catalogName = IMPALA schemaName =  DB_NAME tableName = TABLE_NAME columnName = ….   The way we had configured the external table in MS SQL Polybase 2019, only submitted the IMPALA (default) and TABLE_NAME. Ss soon as we entered the full string: IMPALA.DB_NAME.TABLE_NAME….           the run time reduced with 90 pct.   Thanks you so much for your contribution.   Best regards Henrik ... View more

Tim,     Thank you so much. We have been migrated from CDH 5 to CDH 6 (since CDH 5 is anyway closed down).   We will try investigate using your hints. ... View more

I managed to get some more logging details. To me this looks like a real query, not reading from any cache.   I1015 15:49:44.158821 24416 impala-hs2-server.cc:591] GetColumns(): request=TGetColumnsReq { 01: sessionHandle (struct) = TSessionHandle { 01: sessionId (struct) = THandleIdentifier { 01: guid (string) = "\xcd\xc8\xb1\xe8\xf0\xa3H[\x82\xf1\"u\xe0~SP", 02: secret (string) = "\xfd\x81y\xa1\xf3*A\xb0\xae\x1e\a\xd7\f\xa3\xf0I", }, }, 04: tableName (string) = "mi\\_report\\_workflow\\_fact", 05: columnName (string) = "%", } I1015 15:49:44.638825 24416 impala-server.cc:981] Query f94c41fd14e503dd:10ba472900000000 has timeout of 5m I1015 15:49:44.638913 24416 impala-hs2-server.cc:604] GetColumns(): return_val=TGetColumnsResp { 01: status (struct) = TStatus { 01: statusCode (i32) = 0, }, 02: operationHandle (struct) = TOperationHandle { 01: operationId (struct) = THandleIdentifier { 01: guid (string) = "\xdd\x03\xe5\x14\xfdAL\xf9\x00\x00\x00\x00)G\xba\x10", 02: secret (string) = "\xdd\x03\xe5\x14\xfdAL\xf9\x00\x00\x00\x00)G\xba\x10", }, 02: operationType (i32) = 6, 03: hasResultSet (bool) = true, }, } I1015 15:49:44.640828 24416 impala-hs2-server.cc:699] CloseOperation(): query_id=f94c41fd14e503dd:10ba472900000000 I1015 15:49:44.640846 24416 impala-server.cc:992] UnregisterQuery(): query_id=f94c41fd14e503dd:10ba472900000000 I1015 15:49:44.640856 24416 impala-server.cc:1075] Cancel(): query_id=f94c41fd14e503dd:10ba472900000000 ... View more

Tim,   Thanks!   There's no INVALIDATE METADATA.   I have the profile, but it does not say so much:   Query (id=fb4068c90a80e5dd:33fefd200000000): Summary: Session ID: 4944df8a0226e9cf:2659b7a91151868c Session Type: HIVESERVER2 HiveServer2 Protocol Version: V6 Start Time: 2020-10-14 16:48:25.334065000 End Time: 2020-10-14 16:48:25.840527000 Query Type: DDL Query State: FINISHED Query Status: OK Impala Version: impalad version 2.11.0-cdh5.14.0 RELEASE (build d68206561bce6b26762d62c01a78e6cd27aa7690) User: SVC9125 Connected User: SVC-SQLs-000499@QAONEADR.LOCAL Delegated User: SVC9125 Network Address: 10.96.148.140:51260 Default Db: discovery_gfccmia Sql Statement: GET_COLUMNS Coordinator: ap-hdpdn10t.oneadr.net:22000 Query Timeline: 507.235ms - First row fetched: 504.979ms (504.979ms) - Unregister query: 506.469ms (1.490ms)   I am not sure about if we have any non-standard configurations. I am a business user and will try to get this from the sys admin.    I noticed we have the load_catalog_in_background set to recommended FALSE. But maybe this recommendation don't work for ODBC connections? ... View more