Hive rename column parquet

Hive rename column parquet. If you want to get the file names corresponding to a hive table, the below query will help you. AWS Glue supports using the Parquet format. To enable Hive support while creating a SparkSession in PySpark, you need to use the enableHiveSupport () method. Dec 21, 2020 · One way to complete the above concept in hive query language: select parquet into a non parquet table, do your work to modify the new table, update the new column, etc, then select back into a new parquet table with the new schema. — `DROP COLUMN`: Removes a column from the table. ALTER TABLE table_name CHANGE old_col_name new_col_name new_data_type. Otherwise, it uses default names like partition_0, partition_1, and so on. bdv_table ( registration_dttm timestamp comment 'Registration date', id int comment 'id_for_person', name string comment 'user_name', email string comment 'email address' ) ROW FORMAT SERDE 'parquet. If you are in a code recipe, you'll need to rename your column in your code using select, alias or withColumnRenamed. If the user-defined column name: Syntax: ALTER TABLE table_name CHANGE [COLUMN] col_old To show the columns in the table, the following command uses the SHOW COLUMNS statement. ALTER TABLE EXECUTE supports different commands on a per-connector basis. | monthly_taxi_fleet |. You can also do some of the above with spark or other programming languages. To add columns into partitioned table you need to recreate partitions. serde2. Specifying proper location will save you time whe ndealing with automatically created folders by hive like year=2015/month=12 and it is easier to loop through all of your Jan 11, 2019 · The data is from a Hive table, to be more precise The first table has the properties Serde Library org. test_table(id bigint, place string, total bigint) COMMENT 'This Nov 28, 2017 · In Athena, Tables in parquet are read by names by default. If a particular property was already set, this overrides the old value with the new one. path "/columnname=value/" is always different from path "/columnName=value/" in unix. Jan 8, 2024 · The commands in this article can be used to create or alter an Azure Storage external table in the database from which the command is executed. hadoop. minReaderVersion' = '2', 'delta. The Parquet writer in Spark cannot handle special characters in column names at all, it's unsupported. hive. parquet'; If the file does not end in . | employees2 |. hopefully this should resolve your issue. This gives you the flexibility of reordering the columns in your table or adding new columns in the middle of the table. serde Parquet is a columnar format that is supported by many other data processing systems. Query. ALTER TABLE Statement. For an introduction to the format by the standard authority see, Apache Parquet Documentation Overview. Apr 24, 2019 · alter table table_name change column column_name column_name column_name_type after column_name2; You have to put the column_name twice (or you can change column name) and type of the column. orders; Finally, I double checked the data transformation was correct doing a simple query to myDB. ) and colon (:) yield errors on querying, so they are disallowed in Hive 1. (Older Hive versions just renamed the table in the metastore without moving the HDFS location. parquet'; Figure out which columns/types are in a Parquet file: DESCRIBE SELECT * FROM 'test. The Hive connector detects metastore events and transmits them to Snowflake to keep the external tables synchronized with the Hive metastore. column1 datatype [COMMENT tablecomment], column2 datatype [COMMENT tablecomment], columnN datatype [COMMENT tablecomment]); Example: Mar 23, 2016 · We can use the INPUT__FILE__NAME column. Aug 11, 2023 · But if you are trying to rename a column which is a partition column, it is little difficult and you have to recreate the table with new partition column name. It is needed to set this properties on table: 'delta. We got a request from business Aug 1, 2012 · Here's how to create a hive table with a partition on the column you specified. The ALTER TABLE EXECUTE statement followed by a command and parameters modifies the table according to the specified command and parameters. e, while creating the parquet data itself. edited Dec 24, 2020 at 8:53. 13. ALTER TABLE demo RENAME TO customer; Support was also added for column rename with use of the flag parquet. Jul 5, 2016 · However, some of the JSON events contains spaces in the keys which I want to log and filter/drop such events from the data frame before converting it to Parquet because ;{}()\n\t= are considered special characters in Parquet schema (CatalystSchemaConverter) as listed in [1] below and thus should not be allowed in the column names. Columns are getting renamed however data is getting modified to Null values. This allows users to manage their data in Hive while querying it from Snowflake. So it should be considered a bad practice to rely on case insensitive column names for Hive. AT { REF [ERENCE] | BRANCH } < reference_name> String Optional. like below -. Mar 31, 2018 · @SatyaPavan My original table is something like this:` CREATE EXTERNAL TABLE test_database. Syntax: ALTER TABLE <tablename> ADD COLUMNS (. The file operations need to perform manually corresponding physical filesystem operations. metadata. Newly created partition schema will inherit the table schema. type. SQLContext] = class org. The table refers to the Data Catalog when you run your queries. answered May 19, 2016 at 10:19. df = spark. select a from default. REPLACE COLUMNS can also be used to drop columns. Many options, but in summary: leave Aug 1, 2012 · Here's how to create a hive table with a partition on the column you specified. column. test; ALTER TABLE temp. May 13, 2022 · Let’s try to rename the column Price_in_Usd to Price with comments. Dmitry. Apr 21, 2021 · Use the ALTER command on the table with the CHANGE clause. I have an external table in Hive, the table format is parquet. The following query renames the table from employee to emp. Aug 30, 2018 · ALTER TABLE temp. This feature is available from Hive versions above 0. Hive is a combination of three components: Data files in varying formats, that are typically stored in the Hadoop Distributed File System (HDFS) or in object storage systems such as Amazon S3. access=false that you could set to map schema by column names rather than by column index. Jun 13, 2019 · I'm looking for a way to modify a parquet data table in HIVE to remove some fields. Choose the appropriate approach to load the partitions into the AWS Glue Data Catalog. works and returns data . In the below example we lets set the SerDe to OpenCSVSerde. hive> ALTER TABLE employee RENAME TO emp; JDBC Program. Mar 13, 2016 · 33. Sep 30, 2016 · set spark. Apr 18, 2024 · Applies to: Databricks SQL Databricks Runtime. We will provide an in-depth comparison of their main differences. set parquet. Applies to: Databricks SQL Databricks Runtime. In Hive 0. When this parameter is omitted, the current reference is used. 6, a rename on a managed table moves its HDFS location as well. I have a hive external table in parquet format with following columns: We get the data on daily basis which we ingest into partitions dynamically which are year, month and day. However, next time when I try to read the same parquet table into Spark dataframe, the new column which was added to the parquet table using Hive Alter Table command is not showing up in the df. What are the ways to rename the Athena table columns for parquet file source and still be able to see the data under renamed column after querying? Mar 3, 2015 · I have a quite hefty parquet file where I need to change values for one of the column. Column projection: Columns from the Hive SQL SELECT clause are projected down to the Iceberg readers to reduce the number of columns read. parq'); Use list parameter to read three Apr 28, 2021 · The example mentioned in the link creates a new orders_parquet table called orders_parquet_column_renamed. Apr 24, 2024 · In Spark withColumnRenamed () is used to rename one column or multiple DataFrame column names. ALTER TABLE UNSET is used to drop the table property. #hive. Apr 18, 2014 · location '/my/path/to/parquet'; 6. Apr 21, 2022 · Δ. OR (NOT THE OPTIMISED WAY - won't WORK FOR HUGE DATASETS) read the parquet file using pandas and rename the column for the pandas dataframe. For type changes or renaming columns in Delta Lake see rewrite the data. Using this you can replace a SerDe property or can add a new one. disallow. Spark Session with Hive Enabled. armatita. Jun 21, 2019 · I'm trying to rename a column (date type), but wasn't sure if the syntax was wrong or if this just isn't possible in Spark SQL: brings up this error: org. You can use AWS Glue to read Parquet files from Amazon S3 and from streaming sources as well as write Parquet files to Amazon S3. I am trying to change a column name in an AWS Athena table. Many options, but in summary: leave ALTER TABLE test_all_starscream_types. One way to do this would be to update those values in source text files and recreate parquet file but I'm wond May 11, 2020 · I have an existing External Table called for example YYYYYY that contains n number of columns and this table is loaded daily with partitioned column as extract_date. If you just want to change the column type，not caring about implicit conversions for example,the old columns type is wrong. This function allows user to create a Carbon table from any of the Parquet/Hive/Carbon table. Syntax: ALTER TABLE <current_table_name> RENAME TO <new_table_name>; Command: Let’s rename our table name from the demo to the customer. test REPLACE COLUMNS(user_new string, a string, b string, c string ); Nov 24, 2020 · ALTER TABLE with RENAME is used to change the name of an already existing table in the hive. | employees |. — `SET ALTER TABLE SET command is used for setting the SERDE or SERDE properties in Hive tables. In this solution, we are able to change position of a single column. Sep 11, 2023 · Here are some common subcommands and their descriptions: — `ADD COLUMN`: Adds a new column to the table. new column name emp_id. Case 1: Add new column named new_column. You can set the numrows value for table statistics by changing the TBLPROPERTIES setting for a table or partition. convertMetastoreParquet confuguration to false. Afterwards , you can rename the column as always. | datatypedemo |. Writing the file using IMPALA (preparing the table with HIVE or SPARK previously to avoid complex queries in Impala), due to: Dec 10, 2015 · Hello Experts ! We are looking for a solution in order to create an external hive table to read data from parquet files according to a parquet/avro schema. We have renamed column using hive Alter table change column ( from id to empid) statement and. sql. 6 release) . By default the spark parquet source is using "partition inferring" which means it requires the file path to be partition in Key=Value pairs and the loads happens at the root. ql. Jul 5, 2016 · How can I do such validations in Dataframe on the column names and drop such an event altogether without erroring out the Spark Streaming job. read. access=false but when i want to retrieve data using "select * from tablename" , i am getting the error, Failed with exception java. #Impala. Spark preserves the case of the field name in Dataframe, Parquet Files. This is an old question, but the partition column has to be case sensitive because of the unix filesystem on which it gets stored. Oct 13, 2020 · I´m trying to rename the column name in hive (ORC table) table using alter command. Redshift Spectrum ignores hidden files and files You must store your data on Amazon Simple Storage Service (Amazon S3) buckets as a partition. xiangya. If you are not changing the column name, specify the same column name for both old and new column names. As of version 0. Rename Tables. Jul 16, 2021 · In this post, we’ll look at how to add column comments. For each partitions do Drop then create. temp. Though it is uncommon, we do sometimes change the column names when the situation calls for it. hive> desc test_parquet; OK name string age int dept string salary string city string # Partition Information # col_name data_type comment city string Time taken: 0. You can try this: set hive. parquet, use the read_parquet function: SELECT * FROM read_parquet('test. The SQL select emp_id from xyz is working fine in hive I would to query the table ALTER TABLE name DROP [COLUMN] column_name ALTER TABLE name CHANGE column_name new_name new_type ALTER TABLE name REPLACE COLUMNS (col_spec[, col_spec ]) Rename To… Statement. You can use the => operator for passing named parameter values. -convert_legacy_hive_parquet_utc_timestamps=true. Test select user_a, a, b, c, user_a as user_new from temp. 2. Step 3 – Create a Hive table from PySpark DataFrame. Since the column names are case insensitive in Hive, it showing all the column Aug 18, 2023 · Parquet and Avro are two commonly used data formats. When set to false, Spark SQL will use the Hive SerDe for parquet tables instead of the built in support. 7,026 14 39 41. printSchema output. The Hive connector allows querying data stored in an Apache Hive data warehouse. The JDBC program to rename a table is as follows. When a table is created/accessed using Spark SQL, Case Sensitivity is preserved by Spark storing the details in Table Properties (in hive metastore). table_name. 1 day ago · Examples Read a single Parquet file: SELECT * FROM 'test. | hivedatatypedemo |. the column is added to parquet file, but not exists in a schema in metastore. apache. 0 (see HIVE-10120). Predicate pushdown: Pushdown of the Hive SQL WHERE clause has been implemented so that these filters are used at the Iceberg TableScan level as well as by the Parquet and ORC Readers. What are the ways to rename the Athena table columns for parquet file source and still be able to see the data under renamed column after querying? Parquet is a columnar format that is supported by many other data processing systems. The underlying source data is not affected. The example changes the column o_totalprice name to o_total_price and then runs a query in Athena. In the AWS Glue console, choose Tables in the left navigation pane. SET TABLE PROPERTIES. ) Hive for example has a knob parquet. For each distinct value of the partition key, a subdirectory will be created on HDFS. — `SET TBLPROPERTIES`: Sets table-level properties. dbaglobe. The external table statement defines the table columns, the format of your data files, and the location of your data in Amazon S3. A small example is given below. access SerDe property set to true. Another way of changing the column name is by simply going to AWS Glue -> Select database -> select table -> edit schema -> double click on ALTER TABLE is a logical operation that updates the table metadata in the metastore database that shares with Hive. Spark SQL provides support for both reading and writing Parquet files that automatically preserves the schema of the original data. in other way, how to generate a hive table from a parquet/avro schema ? thanks :) Oct 19, 2018 · I want to add the comment on each column in Hive Parquet table. For Apache Hive-style partitioned paths in key=val style, crawlers automatically populate the column name using the key name. | iotdatademo |. | employees3 |. returns null because it tries to reference column name from parquet schema I think and it doesn't match. parquet. mode' = 'name'. Include the partitioning columns and the root location of partitioned data when you create the table. 2k 9 49 50. com:10000/def> show tables; +----------------------+--+. -use_local_tz_for_unix_timestamp_conversions=true. Oct 26, 2018 · Hive stores the table, field names in lowercase in Hive Metastore. test_rename_columns: REPLACE COLUMNS (`boolean column` BOOLEAN, `date column` INT, `datetime (est)` TIMESTAMP, `datetime column` TIMESTAMP, `decimal column` DECIMAL(38,18), `float column` DOUBLE, `integer column` BIGINT, `key column` STRING, `long column` BIGINT, `money column` DECIMAL(20,2), `string column Hive is case insensitive, while Parquet is not; Hive considers all columns nullable, while nullability in Parquet is significant; Due to this reason, we must reconcile Hive metastore schema with Parquet schema when converting a Hive metastore Parquet table to a Spark SQL Parquet table. ' PARTITIONED BY (date string) STORED AS PARQUET LOCATION 's3 location' ` I dropped this table and created new one like: ` CREATE EXTERNAL TABLE test_database. After executing the Alter statement with comments, the column renamed from price_in_usd to price. If the table is cached, the command clears cached data of the Mar 31, 2022 · I have to change a particular column value PIN to a default value XXXX in all parquet files without changing their names so the _spark_metadata is not disturbed. use-column-names = true and break with the default hive. ALTER TABLE table_name RENAME TO new_table_name; This statement lets you change the name of a table to a different name. use-column-names = false: the column is added to a schema in metastore, but not exists in a parquet file. res3: Class[_ <: org. Refer to Hive SerDe for more information. To change the comment on a table, you can also use COMMENT ON. For example: create table analysis_data stored as parquet as select * from raw_data; Inserted 1000000000 rows in 181. format("parquet")\. ALTER TABLE does not actually rewrite, move, etc, on the actual data files. The ALTER command can also be used to change the column name. Test ADD COLUMNS (user_new string) CASCADE; insert overwrite table temp. minWriterVersion' = '5', 'delta. The AWS documentation indicates that: To make Parquet read by index, which will allow you to rename columns, you must create a table with parquet. Let's see how the user-defined and system-generated column names can be modified. ALTER TABLE schema. spark. mapred. May 1, 2019 · 05-02-2019 12:12 AM. If required, write back the dataframe to a parquet using pandas itself and then progress using spark if required. ALTER TABLE database. lazy. Let’s say you have a large table with a state column and you often required to run analytics-related queries for each state hence, the state column is qualified to be a partition column. metastore. When reading Parquet files, all columns are automatically converted to be nullable for compatibility reasons. ADD new_column INT COMMENT 'new number column'); Case 2: Rename a column new_column to no_of_days. select INPUT__FILE__NAME, name from customer_data; This will give us the file name corresponding to each record. To test the result, SHOW COLUMNS is run again. Alters the schema or properties of a table. parquet'; Create a table from a Parquet file: CREATE TABLE test AS SELECT * FROM 'test. Come to your problem. Here you can change your column name and data type at a time. As I said above, it is implementation-dependent, for example, Impala would not read such parquet tables correctly (fixed in recent Impala 2. — `REPLACE COLUMNS`: Replaces the columns of the table. access . Inserting data from CSV Hive table to Hive Parquet table (Converting to parquet in the process) insert overwrite table myDB. May 7, 2024 · Partition key could be one or multiple columns. Here is the syntax to add comments while creating the table. changes=false; edited May 19, 2016 at 17:55. According to @LostInOverflow's link: Hive is case insensitive, while Parquet is not, so my guess is the following: by using a HiveContext you're probably using some code associated to Apr 25, 2016 · 10. incompatible. col. create table mytable ( col1 int, col2 string) PARTITIONED BY(new_name string); insert into mytable partition (new_name ) select x as col1, y as col2, z as new_name from old May 7, 2024 · Learn how to use Hive ALTER TABLE command to update or drop a partition from a Hive table with examples and tips. Hive query engines: Jun 28, 2019 · There is a separate Hive process that alters the same parquet table to add columns (based on requirements). Andrzej. Here we are not changing the column names so we specify e_id for both old and new column names followed by the data type. If the table is cached, the command Apr 19, 2017 · 1. | tab_name |. access'='true') ALTER TABLE. Is there a way I can change data in a column in the hdfs location either by using spark commands or by using hive commands. alter table new_tbl SET SERDE 'org. lang. Unsupp May 19, 2017 · Alternative to reorder columns is create a view on table. Mar 23, 2016 · We can use the INPUT__FILE__NAME column. and in your spark-submit, you probably use a simple SQLContext. Parquet is a columnar storage format that is great for data analytics, while Avro is a row-oriented format and system used for data serialization. Specifies the reference at which you want to alter the table. Suppose the table is external and the datafiles already contain new columns, do the following: 1. — `CHANGE COLUMN`: Changes the name and data type of a column. 8. 0: jdbc:hive2://cdh-vm. Aug 17, 2017 · how to rename the parquet format table columns i have set the flag parquet. parquet_test . test_table(id string, place string, total string) COMMENT 'This is a test table. table_to_rename rename to new_table_name; edited Jan 7, 2019 at 14:13. Based on the Hive doc below: Rename Table. Parquet column names were previously case sensitive (query had to use column case that matches exactly what was in the metastore), but became case insensitive ( HIVE-7554 ). This command is used to add new columns to the end of existing column. Dec 12, 2016 · Writing the file using HIVE or / and SPARK and suffering the derivated performance problem of setting this two properties. It was created originally for use in Apache Hadoop with systems like Apache Drill, Apache Hive, Apache Impala, and Apache Spark adopting it as a shared standard for high performance data IO. 98s compute stats analysis_data; insert into analysis_data select * from smaller_table_we_forgot_before; Inserted 1000000 rows in 15. In the Hive shell you can run describe employee; and it will show all the columns in the table. Just a design issue we are facing. If you can live without it, you can turn on index access to columns, by specifying. The table is managed but it doesn't matter because I can convert it to external. Normal DDL commands does not affect the table (They cannot be executed). 12 and earlier, only alphanumeric and underscore characters are allowed in table and column names. index. This is beneficial when the user wants to create Carbon table from any other Parquet/Hive table and use the Carbon query engine to query and achieve better query results for cases where Carbon is faster than other file formats. Apr 9, 2017 · 2. column1 datatype [COMMENT tablecomment], column2 datatype [COMMENT tablecomment], columnN datatype [COMMENT tablecomment]); Example: Mar 25, 2019 · In Hive 0. I am trying to add comment as below: create external table parquet_db. LazySimpleSerDe InputFormat org. Metadata about how the data files are mapped to schemas and tables. For example, "ALTER TABLE test_change REPLACE COLUMNS (a int, b int);" will remove column 'c' from test_change's schema. Also the given comments showing in the Describe output. HiveContext. answered Jan 7, 2019 at 13:50. 13 and later, column names can contain any Unicode character (see HIVE-6013), however, dot (. This results in a weird behavior when parquet records are Dec 24, 2017 · This can be done only for tables with a native SerDe (DynamicSerDe, MetadataTypedColumnsetSerDe, LazySimpleSerDe and ColumnarSerDe). Regards. Alter table add columns 2. 053 seconds, Fetched: 10 row(s) hive> ALTER TABLE test_parquet REPLACE COLUMNS (age int,name string, dept string, salary Oct 25, 2017 · # Create parquet Impala table temp with a column a # write parquet file using streaming applicaiton/ map reduce job call parquet schema for that . WITH SERDEPROPERTIES ('parquet. Renamed the column with comments in Hive . Dec 22, 2015 · LOCATION '/user/revathi-prac/'; Now partitioning can be relatively easy done: ALTER TABLE cars ADD PARTITION (year=2015, month=12) LOCATION '/user/revathi-prac/2015/12'. 32s -- Now there are 1001000000 EXECUTE. Is It possible to change a column name without deleting and re-creating the table from scratch ? To define an external table in Amazon Redshift, use the CREATE EXTERNAL TABLE command. Here are three cases, that work when hive. To alter a STREAMING TABLE, use ALTER STREAMING TABLE. access = true. ALTER TABLE SET command is used for setting the table properties. Apache Hive allows us to change the column names similar to many RDBMSs. columnMapping. If you are in a visual recipe, you'll need to rename your column prior to this recipe, for example with By default the spark parquet source is using "partition inferring" which means it requires the file path to be partition in Key=Value pairs and the loads happens at the root. April 18, 2024. The source can be in the scratch directory or in a datalake source. To create a table named PARQUET_TABLE that uses the Parquet format, you would use a command like the following, substituting your own table name, column names, and data types: [impala-host:21000] > create table parquet_table_name (x INT, y STRING) STORED AS PARQUET; In Hive 0. HiveException: java. +----------------------+--+. IOException:org. Apr 8, 2016 · You should try this instead. Table name : xyz. Dec 10, 2015 · After a lot of mistakes, in addition to above explanations, I would add simpler answers. If you don't want to change col_name simply makes old_col_name and new_col_name are same. So if the data on the source side is to be changed where they add a new column and send the batch file, how can we ingest the data. ]table_name (col_name data_type [COMMENT ‘col_comment’],, …) [COMMENT ‘table_comment’] [ROW FORMAT row_format] [FIELDS TERMINATED BY char] [STORED AS file_format Here are three cases, that work when hive. Then you could delete columns too, not just add. It's simple usually to change/modify the exesting table use this syntax in Hive. marc_s. To avoid this, if we assure all the leaf files have identical schema, then we can use. CREATE [EXTERNAL] TABLE [IF NOT EXISTS] [db_name. 1. When writing Parquet files, all columns are automatically converted to be nullable for compatibility reasons. CREATE TABLE employee (employeeId INT, employeeName STRING) PARTITIONED BY (employeeSalary INT); The partition column is specified in the PARTITIONED BY section. An Azure Storage external table references data located in Azure Blob Storage, Azure Data Lake Store Gen1, or Azure Data Lake Store Gen2. Eduardo Yasuda. In this article, we will delve into Parquet and Avro and their key features. Result of the query: The following ALTER TABLE REPLACE COLUMNS command replaces the column names with first_name, last_name, and city. Step 4 – Confirm Hive table is created. This format is a performance-oriented, column-based data format. io. Nov 28, 2016 · 1. Dec 26, 2019 · Recently has been published some modifications which allow to rename columns on DELTA TABLES in Databricks. AnalysisException: ALTER TABLE CHANGE COLUMN is not supported for changing column 'vendor_test_id' with type 'DateType' to 'date_service' with type 'DateType'; The name of the table that you want to alter. parquet_test select * from myDB. Depends on the DataFrame schema, renaming columns might get. The operations that needs to perform manually includes moving The Apache Parquet project provides a standardized open-source columnar storage format for use in data analysis systems. Ok. 16. . The reconciliation rules are: Creating Parquet Tables in Impala. May 5, 2024 · Step 2 – Create PySpark DataFrame. Choose the table created by the crawler, and then choose View Partitions. old column name : id. Apache Arrow is an ideal in-memory Sep 16, 2018 · Change the column names at the source itself, i. OpenCSVSerde'; alter table properties [tblproperties] ALTER TABLE table_name SET TBLPROPERTIES ('prop1'='value1'); Dec 24, 2017 · Hive alter table DDL to rename table and add/replace columns. Redshift Spectrum scans the files in the specified folder and any subfolders. From old_name to new_name. Oct 16, 2020 · So what I would like to do, is to rename the export_date column to export_date_exp. Recreate partitions. ps oq ju rw xb ao kb pn sl cj