DongLiang-0 commented on code in PR #1828: URL: https://github.com/apache/doris-website/pull/1828#discussion_r1919524659
########## docs/sql-manual/sql-functions/table-valued-functions/hdfs.md: ########## @@ -24,139 +24,117 @@ specific language governing permissions and limitations under the License. --> -## HDFS - -### Name - -hdfs - -### Description +## Description HDFS table-valued-function(tvf), allows users to read and access file contents on S3-compatible object storage, just like accessing relational table. Currently supports `csv/csv_with_names/csv_with_names_and_types/json/parquet/orc` file format. -#### syntax +## Syntax ```sql -hdfs( - "uri" = "..", - "fs.defaultFS" = "...", - "hadoop.username" = "...", - "format" = "csv", - "keyn" = "valuen" - ... +HDFS( + "uri" = "<uri>", + "fs.defaultFS" = "<fs_defaultFS>", + "hadoop.username" = "<hadoop_username>", + "format" = "<format>", + [, "<optional_property_key>" = "<optional_property_value>" [, ...] ] ); ``` -**parameter description** - -Related parameters for accessing hdfs: - -- `uri`: (required) hdfs uri. If the uri path does not exist or the files are empty files, hdfs tvf will return an empty result set. -- `fs.defaultFS`: (required) -- `hadoop.username`: (required) Can be any string, but cannot be empty. -- `hadoop.security.authentication`: (optional) -- `hadoop.username`: (optional) -- `hadoop.kerberos.principal`: (optional) -- `hadoop.kerberos.keytab`: (optional) -- `dfs.client.read.shortcircuit`: (optional) -- `dfs.domain.socket.path`: (optional) - -Related parameters for accessing HDFS in HA mode: - -- `dfs.nameservices`: (optional) -- `dfs.ha.namenodes.your-nameservices`: (optional) -- `dfs.namenode.rpc-address.your-nameservices.your-namenode`: (optional) -- `dfs.client.failover.proxy.provider.your-nameservices`: (optional) - -File format parameters: - -- `format`: (required) Currently support `csv/csv_with_names/csv_with_names_and_types/json/parquet/orc/avro` -- `column_separator`: (optional) default `\t`. -- `line_delimiter`: (optional) default `\n`. -- `compress_type`: (optional) Currently support `UNKNOWN/PLAIN/GZ/LZO/BZ2/LZ4FRAME/DEFLATE/SNAPPYBLOCK`. Default value is `UNKNOWN`, it will automatically infer the type based on the suffix of `uri`. - - The following 6 parameters are used for loading in json format. For specific usage methods, please refer to: [Json Load](../../../data-operate/import/import-way/load-json-format.md) - -- `read_json_by_line`: (optional) default `"true"` -- `strip_outer_array`: (optional) default `"false"` -- `json_root`: (optional) default `""` -- `json_paths`: (optional) default `""` -- `num_as_string`: (optional) default `false` -- `fuzzy_parse`: (optional) default `false` - - The following 2 parameters are used for loading in csv format: - -- `trim_double_quotes`: Boolean type (optional), the default value is `false`. True means that the outermost double quotes of each field in the csv file are trimmed. -- `skip_lines`: Integer type (optional), the default value is 0. It will skip some lines in the head of csv file. It will be disabled when the format is `csv_with_names` or `csv_with_names_and_types`. - -other kinds of parameters: - -- `path_partition_keys`: (optional) Specifies the column names carried in the file path. For example, if the file path is /path/to/city=beijing/date="2023-07-09", you should fill in `path_partition_keys="city,date"`. It will automatically read the corresponding column names and values from the path during load process. -- `resource`：（optional）Specify the resource name. Hdfs Tvf can use the existing Hdfs resource to directly access Hdfs. You can refer to the method for creating an Hdfs resource: [CREATE-RESOURCE](../../sql-statements/Data-Definition-Statements/Create/CREATE-RESOURCE.md). This property is supported starting from version 2.1.4. - -:::tip Tip -To directly query a TVF or create a VIEW based on that TVF, you need to have usage permission for that resource. To query a VIEW created based on TVF, you only need select permission for that VIEW. -::: - -### Examples - -Read and access csv format files on hdfs storage. - -```sql -MySQL [(none)]> select * from hdfs( - "uri" = "hdfs://127.0.0.1:842/user/doris/csv_format_test/student.csv", - "fs.defaultFS" = "hdfs://127.0.0.1:8424", - "hadoop.username" = "doris", - "format" = "csv"); -+------+---------+------+ -| c1 | c2 | c3 | -+------+---------+------+ -| 1 | alice | 18 | -| 2 | bob | 20 | -| 3 | jack | 24 | -| 4 | jackson | 19 | -| 5 | liming | 18 | -+------+---------+------+ -``` - -Read and access csv format files on hdfs storage in HA mode. - -```sql -MySQL [(none)]> select * from hdfs( - "uri" = "hdfs://127.0.0.1:842/user/doris/csv_format_test/student.csv", - "fs.defaultFS" = "hdfs://127.0.0.1:8424", - "hadoop.username" = "doris", - "format" = "csv", - "dfs.nameservices" = "my_hdfs", - "dfs.ha.namenodes.my_hdfs" = "nn1,nn2", - "dfs.namenode.rpc-address.my_hdfs.nn1" = "nanmenode01:8020", - "dfs.namenode.rpc-address.my_hdfs.nn2" = "nanmenode02:8020", - "dfs.client.failover.proxy.provider.my_hdfs" = "org.apache.hadoop.hdfs.server.namenode.ha.ConfiguredFailoverProxyProvider"); -+------+---------+------+ -| c1 | c2 | c3 | -+------+---------+------+ -| 1 | alice | 18 | -| 2 | bob | 20 | -| 3 | jack | 24 | -| 4 | jackson | 19 | -| 5 | liming | 18 | -+------+---------+------+ -``` - -Can be used with `desc function` : - -```sql -MySQL [(none)]> desc function hdfs( - "uri" = "hdfs://127.0.0.1:8424/user/doris/csv_format_test/student_with_names.csv", - "fs.defaultFS" = "hdfs://127.0.0.1:8424", - "hadoop.username" = "doris", - "format" = "csv_with_names"); -``` - -### Keywords - - hdfs, table-valued-function, tvf - -### Best Practice - - For more detailed usage of HDFS tvf, please refer to [S3](./s3.md) tvf, The only difference between them is the way of accessing the storage system. +## Required Parameters Review Comment: 在可选参数下面加了这样一段描述了 ``` ## 可选参数 (Optional Parameters) 上述语法中的 `optional_property_key` 可以按需从以下列表中选取对应的参数，`optional_property_value` 则为该参数的值 `` -- This is an automated message from the Apache Git Service. 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