maropu commented on a change in pull request #31010: URL: https://github.com/apache/spark/pull/31010#discussion_r612022046
########## File path: docs/sql-ref-syntax-qry-select-transform.md ########## @@ -0,0 +1,254 @@ +--- +layout: global +title: TRANSFORM +displayTitle: TRANSFORM +license: | + Licensed to the Apache Software Foundation (ASF) under one or more + contributor license agreements. See the NOTICE file distributed with + this work for additional information regarding copyright ownership. + The ASF licenses this file to You under the Apache License, Version 2.0 + (the "License"); you may not use this file except in compliance with + the License. You may obtain a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + + Unless required by applicable law or agreed to in writing, software + distributed under the License is distributed on an "AS IS" BASIS, + WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + See the License for the specific language governing permissions and + limitations under the License. +--- + +### Description + +The `TRANSFORM` clause is used to specify a Hive-style transform (`SELECT TRANSFORM`/`MAP`/`REDUCE`) +query specification to transform the input by running a specified script. Users can +plug in their own custom mappers or reducers in the data stream by using features natively supported +in the Spark SQL. In order to run a custom mapper script `map_script` or a custom +reducer script `reduce_script` the user can issue the command which uses the `TRANSFORM` +clause to embed the mapper or the reducer scripts. + +### Syntax + +```sql +SELECT { TRANSFORM ( named_expression [ , ... ] ) | MAP named_expression [ , ... ] | REDUCE named_expression [ , ... ] } + [ rowFormat ] + [ RECORDWRITER recordWriter_class ] + USING script [ AS ( [ col_name [ col_type ] ] [ , ... ] ) ] + [ rowFormat ] + [ RECORDREADER recordReader_class ] +``` + +While `rowFormat` are defined as +```sql +{ ROW FORMAT SERDE serde_class [ WITH SERDEPROPERTIES serde_props ] | + ROW FORMAT DELIMITED + [ FIELDS TERMINATED BY fields_terminated_char [ ESCAPED BY escapedBy ] ] + [ COLLECTION ITEMS TERMINATED BY collectionItemsTerminatedBy ] + [ MAP KEYS TERMINATED BY keysTerminatedBy ] + [ LINES TERMINATED BY linesSeparatedBy ] + [ NULL DEFINED AS nullDefinedAs ] } +``` + +### Parameters + +* **named_expression** + + An expression with an assigned name. In general, it denotes a column expression. + + **Syntax:** `expression [AS] [alias]` + +* **row_format** + + Spark uses the `SERDE` clause to specify a custom SerDe for one table. Otherwise, use the `DELIMITED` clause to use the native SerDe and specify the delimiter, escape character, null character and so on. + +* **serde_class** + + Specifies a fully-qualified class name of a custom SerDe. + +* **serde_props** + + A list of key-value pairs that is used to tag the SerDe definition. + +* **FIELDS TERMINATED BY** + + Used to define a column separator. + +* **COLLECTION ITEMS TERMINATED BY** + + Used to define a collection item separator. + +* **MAP KEYS TERMINATED BY** + + Used to define a map key separator. + +* **LINES TERMINATED BY** + + Used to define a row separator. + +* **NULL DEFINED AS** + + Used to define the specific value for NULL. + +* **ESCAPED BY** + + Used for escape mechanism. + +* **RECORDREADER** + + Specifies a custom RecordReader for one table. + +* **RECORDWRITER** + + Specifies a custom RecordWriter for one table. + +* **recordReader_class** + + Specifies a fully-qualified class name of a custom RecordReader. A default value is `org.apache.hadoop.hive.ql.exec.TextRecordReader`. + +* **recordWriter_class** + + Specifies a fully-qualified class name of a custom RecordWriter. A default value is `org.apache.hadoop.hive.ql.exec.TextRecordWriter`. + +* **script** + + Specifies a command to process data. + +### Serde behavior + +Spark uses Hive Serde `org.apache.hadoop.hive.serde2.lazy.LazySimpleSerDe` by default, columns will be transformed +to `STRING` and combined by tabs before feeding to the user script. All `NULL` values will be converted +to the literal string `"\N"` in order to differentiate `NULL` values from empty strings. The standard output of the +user script will be treated as TAB-separated STRING columns, any cell containing only `"\N"` will be re-interpreted +as a `NULL`, and then the resulting STRING column will be cast to the data type specified in the table declaration +in the usual way. If the actual number of output columns is less than the number of specified output columns, +insufficient output columns will be supplemented with `NULL`. If the actual number of output columns is more than the +number of specified output columns, the output columns will only select the corresponding columns and the remaining part Review comment: btw, we already have some test for these behaviours? I couldn't find it though. ########## File path: docs/sql-ref-syntax-qry-select-transform.md ########## @@ -0,0 +1,254 @@ +--- +layout: global +title: TRANSFORM +displayTitle: TRANSFORM +license: | + Licensed to the Apache Software Foundation (ASF) under one or more + contributor license agreements. See the NOTICE file distributed with + this work for additional information regarding copyright ownership. + The ASF licenses this file to You under the Apache License, Version 2.0 + (the "License"); you may not use this file except in compliance with + the License. You may obtain a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + + Unless required by applicable law or agreed to in writing, software + distributed under the License is distributed on an "AS IS" BASIS, + WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + See the License for the specific language governing permissions and + limitations under the License. +--- + +### Description + +The `TRANSFORM` clause is used to specify a Hive-style transform (`SELECT TRANSFORM`/`MAP`/`REDUCE`) +query specification to transform the input by running a specified script. Users can +plug in their own custom mappers or reducers in the data stream by using features natively supported +in the Spark SQL. In order to run a custom mapper script `map_script` or a custom +reducer script `reduce_script` the user can issue the command which uses the `TRANSFORM` +clause to embed the mapper or the reducer scripts. + +### Syntax + +```sql +SELECT { TRANSFORM ( named_expression [ , ... ] ) | MAP named_expression [ , ... ] | REDUCE named_expression [ , ... ] } + [ rowFormat ] Review comment: `rowFormat` -> `row_format` ########## File path: docs/sql-ref-syntax-qry-select-transform.md ########## @@ -0,0 +1,254 @@ +--- +layout: global +title: TRANSFORM +displayTitle: TRANSFORM +license: | + Licensed to the Apache Software Foundation (ASF) under one or more + contributor license agreements. See the NOTICE file distributed with + this work for additional information regarding copyright ownership. + The ASF licenses this file to You under the Apache License, Version 2.0 + (the "License"); you may not use this file except in compliance with + the License. You may obtain a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + + Unless required by applicable law or agreed to in writing, software + distributed under the License is distributed on an "AS IS" BASIS, + WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + See the License for the specific language governing permissions and + limitations under the License. +--- + +### Description + +The `TRANSFORM` clause is used to specify a Hive-style transform (`SELECT TRANSFORM`/`MAP`/`REDUCE`) +query specification to transform the input by running a specified script. Users can +plug in their own custom mappers or reducers in the data stream by using features natively supported +in the Spark SQL. In order to run a custom mapper script `map_script` or a custom +reducer script `reduce_script` the user can issue the command which uses the `TRANSFORM` +clause to embed the mapper or the reducer scripts. + +### Syntax + +```sql +SELECT { TRANSFORM ( named_expression [ , ... ] ) | MAP named_expression [ , ... ] | REDUCE named_expression [ , ... ] } + [ rowFormat ] + [ RECORDWRITER recordWriter_class ] + USING script [ AS ( [ col_name [ col_type ] ] [ , ... ] ) ] + [ rowFormat ] Review comment: Probably, `[ rowFormat ]` -> `[ ROW FORMAT row_format ]` ########## File path: docs/sql-ref-syntax-qry-select-transform.md ########## @@ -0,0 +1,254 @@ +--- +layout: global +title: TRANSFORM +displayTitle: TRANSFORM +license: | + Licensed to the Apache Software Foundation (ASF) under one or more + contributor license agreements. See the NOTICE file distributed with + this work for additional information regarding copyright ownership. + The ASF licenses this file to You under the Apache License, Version 2.0 + (the "License"); you may not use this file except in compliance with + the License. You may obtain a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + + Unless required by applicable law or agreed to in writing, software + distributed under the License is distributed on an "AS IS" BASIS, + WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + See the License for the specific language governing permissions and + limitations under the License. +--- + +### Description + +The `TRANSFORM` clause is used to specify a Hive-style transform (`SELECT TRANSFORM`/`MAP`/`REDUCE`) +query specification to transform the input by running a specified script. Users can +plug in their own custom mappers or reducers in the data stream by using features natively supported +in the Spark SQL. In order to run a custom mapper script `map_script` or a custom +reducer script `reduce_script` the user can issue the command which uses the `TRANSFORM` +clause to embed the mapper or the reducer scripts. + +### Syntax + +```sql +SELECT { TRANSFORM ( named_expression [ , ... ] ) | MAP named_expression [ , ... ] | REDUCE named_expression [ , ... ] } + [ rowFormat ] + [ RECORDWRITER recordWriter_class ] + USING script [ AS ( [ col_name [ col_type ] ] [ , ... ] ) ] + [ rowFormat ] Review comment: `rowFormat` -> `row_format` ########## File path: docs/sql-ref-syntax-qry-select-transform.md ########## @@ -0,0 +1,254 @@ +--- +layout: global +title: TRANSFORM +displayTitle: TRANSFORM +license: | + Licensed to the Apache Software Foundation (ASF) under one or more + contributor license agreements. See the NOTICE file distributed with + this work for additional information regarding copyright ownership. + The ASF licenses this file to You under the Apache License, Version 2.0 + (the "License"); you may not use this file except in compliance with + the License. You may obtain a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + + Unless required by applicable law or agreed to in writing, software + distributed under the License is distributed on an "AS IS" BASIS, + WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + See the License for the specific language governing permissions and + limitations under the License. +--- + +### Description + +The `TRANSFORM` clause is used to specify a Hive-style transform (`SELECT TRANSFORM`/`MAP`/`REDUCE`) +query specification to transform the input by running a specified script. Users can +plug in their own custom mappers or reducers in the data stream by using features natively supported +in the Spark SQL. In order to run a custom mapper script `map_script` or a custom +reducer script `reduce_script` the user can issue the command which uses the `TRANSFORM` +clause to embed the mapper or the reducer scripts. + +### Syntax + +```sql +SELECT { TRANSFORM ( named_expression [ , ... ] ) | MAP named_expression [ , ... ] | REDUCE named_expression [ , ... ] } + [ rowFormat ] + [ RECORDWRITER recordWriter_class ] + USING script [ AS ( [ col_name [ col_type ] ] [ , ... ] ) ] + [ rowFormat ] + [ RECORDREADER recordReader_class ] +``` + +While `rowFormat` are defined as +```sql +{ ROW FORMAT SERDE serde_class [ WITH SERDEPROPERTIES serde_props ] | Review comment: `WITH SERDEPROPERTIES serde_props` -> `WITH SERDEPROPERTIES (k1=v1, k2=v2, ... )` ########## File path: docs/sql-ref-syntax-qry-select-transform.md ########## @@ -0,0 +1,254 @@ +--- +layout: global +title: TRANSFORM +displayTitle: TRANSFORM +license: | + Licensed to the Apache Software Foundation (ASF) under one or more + contributor license agreements. See the NOTICE file distributed with + this work for additional information regarding copyright ownership. + The ASF licenses this file to You under the Apache License, Version 2.0 + (the "License"); you may not use this file except in compliance with + the License. You may obtain a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + + Unless required by applicable law or agreed to in writing, software + distributed under the License is distributed on an "AS IS" BASIS, + WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + See the License for the specific language governing permissions and + limitations under the License. +--- + +### Description + +The `TRANSFORM` clause is used to specify a Hive-style transform (`SELECT TRANSFORM`/`MAP`/`REDUCE`) +query specification to transform the input by running a specified script. Users can +plug in their own custom mappers or reducers in the data stream by using features natively supported +in the Spark SQL. In order to run a custom mapper script `map_script` or a custom +reducer script `reduce_script` the user can issue the command which uses the `TRANSFORM` +clause to embed the mapper or the reducer scripts. + +### Syntax + +```sql +SELECT { TRANSFORM ( named_expression [ , ... ] ) | MAP named_expression [ , ... ] | REDUCE named_expression [ , ... ] } + [ rowFormat ] + [ RECORDWRITER recordWriter_class ] + USING script [ AS ( [ col_name [ col_type ] ] [ , ... ] ) ] + [ rowFormat ] + [ RECORDREADER recordReader_class ] +``` + +While `rowFormat` are defined as +```sql +{ ROW FORMAT SERDE serde_class [ WITH SERDEPROPERTIES serde_props ] | + ROW FORMAT DELIMITED + [ FIELDS TERMINATED BY fields_terminated_char [ ESCAPED BY escapedBy ] ] + [ COLLECTION ITEMS TERMINATED BY collectionItemsTerminatedBy ] + [ MAP KEYS TERMINATED BY keysTerminatedBy ] Review comment: `keysTerminatedBy ` -> `map_key_terminated_char` ########## File path: docs/sql-ref-syntax-qry-select-transform.md ########## @@ -0,0 +1,254 @@ +--- +layout: global +title: TRANSFORM +displayTitle: TRANSFORM +license: | + Licensed to the Apache Software Foundation (ASF) under one or more + contributor license agreements. See the NOTICE file distributed with + this work for additional information regarding copyright ownership. + The ASF licenses this file to You under the Apache License, Version 2.0 + (the "License"); you may not use this file except in compliance with + the License. You may obtain a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + + Unless required by applicable law or agreed to in writing, software + distributed under the License is distributed on an "AS IS" BASIS, + WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + See the License for the specific language governing permissions and + limitations under the License. +--- + +### Description + +The `TRANSFORM` clause is used to specify a Hive-style transform (`SELECT TRANSFORM`/`MAP`/`REDUCE`) +query specification to transform the input by running a specified script. Users can +plug in their own custom mappers or reducers in the data stream by using features natively supported +in the Spark SQL. In order to run a custom mapper script `map_script` or a custom +reducer script `reduce_script` the user can issue the command which uses the `TRANSFORM` +clause to embed the mapper or the reducer scripts. + +### Syntax + +```sql +SELECT { TRANSFORM ( named_expression [ , ... ] ) | MAP named_expression [ , ... ] | REDUCE named_expression [ , ... ] } + [ rowFormat ] + [ RECORDWRITER recordWriter_class ] + USING script [ AS ( [ col_name [ col_type ] ] [ , ... ] ) ] + [ rowFormat ] + [ RECORDREADER recordReader_class ] +``` + +While `rowFormat` are defined as +```sql +{ ROW FORMAT SERDE serde_class [ WITH SERDEPROPERTIES serde_props ] | + ROW FORMAT DELIMITED + [ FIELDS TERMINATED BY fields_terminated_char [ ESCAPED BY escapedBy ] ] + [ COLLECTION ITEMS TERMINATED BY collectionItemsTerminatedBy ] Review comment: `collectionItemsTerminatedBy` -> `collection_items_terminated_char` see: https://github.com/apache/spark/blame/master/docs/sql-ref-syntax-ddl-create-table-hiveformat.md#L46 ########## File path: docs/sql-ref-syntax-qry-select-transform.md ########## @@ -0,0 +1,254 @@ +--- +layout: global +title: TRANSFORM +displayTitle: TRANSFORM +license: | + Licensed to the Apache Software Foundation (ASF) under one or more + contributor license agreements. See the NOTICE file distributed with + this work for additional information regarding copyright ownership. + The ASF licenses this file to You under the Apache License, Version 2.0 + (the "License"); you may not use this file except in compliance with + the License. You may obtain a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + + Unless required by applicable law or agreed to in writing, software + distributed under the License is distributed on an "AS IS" BASIS, + WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + See the License for the specific language governing permissions and + limitations under the License. +--- + +### Description + +The `TRANSFORM` clause is used to specify a Hive-style transform (`SELECT TRANSFORM`/`MAP`/`REDUCE`) +query specification to transform the input by running a specified script. Users can +plug in their own custom mappers or reducers in the data stream by using features natively supported +in the Spark SQL. In order to run a custom mapper script `map_script` or a custom +reducer script `reduce_script` the user can issue the command which uses the `TRANSFORM` +clause to embed the mapper or the reducer scripts. + +### Syntax + +```sql +SELECT { TRANSFORM ( named_expression [ , ... ] ) | MAP named_expression [ , ... ] | REDUCE named_expression [ , ... ] } + [ rowFormat ] + [ RECORDWRITER recordWriter_class ] + USING script [ AS ( [ col_name [ col_type ] ] [ , ... ] ) ] + [ rowFormat ] + [ RECORDREADER recordReader_class ] +``` + +While `rowFormat` are defined as +```sql +{ ROW FORMAT SERDE serde_class [ WITH SERDEPROPERTIES serde_props ] | + ROW FORMAT DELIMITED + [ FIELDS TERMINATED BY fields_terminated_char [ ESCAPED BY escapedBy ] ] + [ COLLECTION ITEMS TERMINATED BY collectionItemsTerminatedBy ] + [ MAP KEYS TERMINATED BY keysTerminatedBy ] + [ LINES TERMINATED BY linesSeparatedBy ] Review comment: `linesSeparatedBy ` -> `row_terminated_char` ########## File path: docs/sql-ref-syntax-qry-select-transform.md ########## @@ -0,0 +1,254 @@ +--- +layout: global +title: TRANSFORM +displayTitle: TRANSFORM +license: | + Licensed to the Apache Software Foundation (ASF) under one or more + contributor license agreements. See the NOTICE file distributed with + this work for additional information regarding copyright ownership. + The ASF licenses this file to You under the Apache License, Version 2.0 + (the "License"); you may not use this file except in compliance with + the License. You may obtain a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + + Unless required by applicable law or agreed to in writing, software + distributed under the License is distributed on an "AS IS" BASIS, + WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + See the License for the specific language governing permissions and + limitations under the License. +--- + +### Description + +The `TRANSFORM` clause is used to specify a Hive-style transform (`SELECT TRANSFORM`/`MAP`/`REDUCE`) +query specification to transform the input by running a specified script. Users can +plug in their own custom mappers or reducers in the data stream by using features natively supported +in the Spark SQL. In order to run a custom mapper script `map_script` or a custom +reducer script `reduce_script` the user can issue the command which uses the `TRANSFORM` +clause to embed the mapper or the reducer scripts. + +### Syntax + +```sql +SELECT { TRANSFORM ( named_expression [ , ... ] ) | MAP named_expression [ , ... ] | REDUCE named_expression [ , ... ] } + [ rowFormat ] + [ RECORDWRITER recordWriter_class ] + USING script [ AS ( [ col_name [ col_type ] ] [ , ... ] ) ] + [ rowFormat ] + [ RECORDREADER recordReader_class ] +``` + +While `rowFormat` are defined as +```sql +{ ROW FORMAT SERDE serde_class [ WITH SERDEPROPERTIES serde_props ] | + ROW FORMAT DELIMITED + [ FIELDS TERMINATED BY fields_terminated_char [ ESCAPED BY escapedBy ] ] + [ COLLECTION ITEMS TERMINATED BY collectionItemsTerminatedBy ] + [ MAP KEYS TERMINATED BY keysTerminatedBy ] + [ LINES TERMINATED BY linesSeparatedBy ] + [ NULL DEFINED AS nullDefinedAs ] } +``` + +### Parameters + +* **named_expression** + + An expression with an assigned name. In general, it denotes a column expression. + + **Syntax:** `expression [AS] [alias]` + +* **row_format** + + Spark uses the `SERDE` clause to specify a custom SerDe for one table. Otherwise, use the `DELIMITED` clause to use the native SerDe and specify the delimiter, escape character, null character and so on. + +* **serde_class** + + Specifies a fully-qualified class name of a custom SerDe. + +* **serde_props** + + A list of key-value pairs that is used to tag the SerDe definition. + +* **FIELDS TERMINATED BY** + + Used to define a column separator. + +* **COLLECTION ITEMS TERMINATED BY** + + Used to define a collection item separator. + +* **MAP KEYS TERMINATED BY** + + Used to define a map key separator. + +* **LINES TERMINATED BY** + + Used to define a row separator. + +* **NULL DEFINED AS** + + Used to define the specific value for NULL. + +* **ESCAPED BY** + + Used for escape mechanism. + +* **RECORDREADER** + + Specifies a custom RecordReader for one table. + +* **RECORDWRITER** + + Specifies a custom RecordWriter for one table. + +* **recordReader_class** + + Specifies a fully-qualified class name of a custom RecordReader. A default value is `org.apache.hadoop.hive.ql.exec.TextRecordReader`. + +* **recordWriter_class** + + Specifies a fully-qualified class name of a custom RecordWriter. A default value is `org.apache.hadoop.hive.ql.exec.TextRecordWriter`. + +* **script** + + Specifies a command to process data. + +### Serde behavior Review comment: `Serde` -> `SerDe ` ########## File path: docs/sql-ref-syntax-qry-select-transform.md ########## @@ -0,0 +1,254 @@ +--- +layout: global +title: TRANSFORM +displayTitle: TRANSFORM +license: | + Licensed to the Apache Software Foundation (ASF) under one or more + contributor license agreements. See the NOTICE file distributed with + this work for additional information regarding copyright ownership. + The ASF licenses this file to You under the Apache License, Version 2.0 + (the "License"); you may not use this file except in compliance with + the License. You may obtain a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + + Unless required by applicable law or agreed to in writing, software + distributed under the License is distributed on an "AS IS" BASIS, + WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + See the License for the specific language governing permissions and + limitations under the License. +--- + +### Description + +The `TRANSFORM` clause is used to specify a Hive-style transform (`SELECT TRANSFORM`/`MAP`/`REDUCE`) +query specification to transform the input by running a specified script. Users can +plug in their own custom mappers or reducers in the data stream by using features natively supported +in the Spark SQL. In order to run a custom mapper script `map_script` or a custom +reducer script `reduce_script` the user can issue the command which uses the `TRANSFORM` +clause to embed the mapper or the reducer scripts. + +### Syntax + +```sql +SELECT { TRANSFORM ( named_expression [ , ... ] ) | MAP named_expression [ , ... ] | REDUCE named_expression [ , ... ] } + [ rowFormat ] + [ RECORDWRITER recordWriter_class ] + USING script [ AS ( [ col_name [ col_type ] ] [ , ... ] ) ] + [ rowFormat ] + [ RECORDREADER recordReader_class ] Review comment: `recordReader_class` -> `record_reader_class ` ########## File path: docs/sql-ref-syntax-qry-select-transform.md ########## @@ -0,0 +1,254 @@ +--- +layout: global +title: TRANSFORM +displayTitle: TRANSFORM +license: | + Licensed to the Apache Software Foundation (ASF) under one or more + contributor license agreements. See the NOTICE file distributed with + this work for additional information regarding copyright ownership. + The ASF licenses this file to You under the Apache License, Version 2.0 + (the "License"); you may not use this file except in compliance with + the License. You may obtain a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + + Unless required by applicable law or agreed to in writing, software + distributed under the License is distributed on an "AS IS" BASIS, + WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + See the License for the specific language governing permissions and + limitations under the License. +--- + +### Description + +The `TRANSFORM` clause is used to specify a Hive-style transform (`SELECT TRANSFORM`/`MAP`/`REDUCE`) +query specification to transform the input by running a specified script. Users can +plug in their own custom mappers or reducers in the data stream by using features natively supported +in the Spark SQL. In order to run a custom mapper script `map_script` or a custom +reducer script `reduce_script` the user can issue the command which uses the `TRANSFORM` +clause to embed the mapper or the reducer scripts. + +### Syntax + +```sql +SELECT { TRANSFORM ( named_expression [ , ... ] ) | MAP named_expression [ , ... ] | REDUCE named_expression [ , ... ] } + [ rowFormat ] + [ RECORDWRITER recordWriter_class ] Review comment: `recordWriter_class` -> `record_writer_class ` ########## File path: docs/sql-ref-syntax-qry-select-transform.md ########## @@ -0,0 +1,254 @@ +--- +layout: global +title: TRANSFORM +displayTitle: TRANSFORM +license: | + Licensed to the Apache Software Foundation (ASF) under one or more + contributor license agreements. See the NOTICE file distributed with + this work for additional information regarding copyright ownership. + The ASF licenses this file to You under the Apache License, Version 2.0 + (the "License"); you may not use this file except in compliance with + the License. You may obtain a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + + Unless required by applicable law or agreed to in writing, software + distributed under the License is distributed on an "AS IS" BASIS, + WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + See the License for the specific language governing permissions and + limitations under the License. +--- + +### Description + +The `TRANSFORM` clause is used to specify a Hive-style transform (`SELECT TRANSFORM`/`MAP`/`REDUCE`) +query specification to transform the input by running a specified script. Users can +plug in their own custom mappers or reducers in the data stream by using features natively supported +in the Spark SQL. In order to run a custom mapper script `map_script` or a custom +reducer script `reduce_script` the user can issue the command which uses the `TRANSFORM` +clause to embed the mapper or the reducer scripts. + +### Syntax + +```sql +SELECT { TRANSFORM ( named_expression [ , ... ] ) | MAP named_expression [ , ... ] | REDUCE named_expression [ , ... ] } + [ rowFormat ] + [ RECORDWRITER recordWriter_class ] + USING script [ AS ( [ col_name [ col_type ] ] [ , ... ] ) ] + [ rowFormat ] + [ RECORDREADER recordReader_class ] +``` + +While `rowFormat` are defined as +```sql +{ ROW FORMAT SERDE serde_class [ WITH SERDEPROPERTIES serde_props ] | + ROW FORMAT DELIMITED + [ FIELDS TERMINATED BY fields_terminated_char [ ESCAPED BY escapedBy ] ] Review comment: `escapedBy ` -> `escaped_char` ########## File path: docs/sql-ref-syntax-qry-select-transform.md ########## @@ -0,0 +1,254 @@ +--- +layout: global +title: TRANSFORM +displayTitle: TRANSFORM +license: | + Licensed to the Apache Software Foundation (ASF) under one or more + contributor license agreements. See the NOTICE file distributed with + this work for additional information regarding copyright ownership. + The ASF licenses this file to You under the Apache License, Version 2.0 + (the "License"); you may not use this file except in compliance with + the License. You may obtain a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + + Unless required by applicable law or agreed to in writing, software + distributed under the License is distributed on an "AS IS" BASIS, + WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + See the License for the specific language governing permissions and + limitations under the License. +--- + +### Description + +The `TRANSFORM` clause is used to specify a Hive-style transform (`SELECT TRANSFORM`/`MAP`/`REDUCE`) +query specification to transform the input by running a specified script. Users can +plug in their own custom mappers or reducers in the data stream by using features natively supported +in the Spark SQL. In order to run a custom mapper script `map_script` or a custom +reducer script `reduce_script` the user can issue the command which uses the `TRANSFORM` +clause to embed the mapper or the reducer scripts. + +### Syntax + +```sql +SELECT { TRANSFORM ( named_expression [ , ... ] ) | MAP named_expression [ , ... ] | REDUCE named_expression [ , ... ] } + [ rowFormat ] + [ RECORDWRITER recordWriter_class ] + USING script [ AS ( [ col_name [ col_type ] ] [ , ... ] ) ] + [ rowFormat ] + [ RECORDREADER recordReader_class ] +``` + +While `rowFormat` are defined as +```sql +{ ROW FORMAT SERDE serde_class [ WITH SERDEPROPERTIES serde_props ] | + ROW FORMAT DELIMITED + [ FIELDS TERMINATED BY fields_terminated_char [ ESCAPED BY escapedBy ] ] + [ COLLECTION ITEMS TERMINATED BY collectionItemsTerminatedBy ] + [ MAP KEYS TERMINATED BY keysTerminatedBy ] + [ LINES TERMINATED BY linesSeparatedBy ] + [ NULL DEFINED AS nullDefinedAs ] } Review comment: `nullDefinedAs` -> `null_char` -- This is an automated message from the Apache Git Service. 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