DROP TABLE IF EXISTS hql.customer PURGE; Underlying data in HDFS will be purged directly and table cannot be restored. In our example, we are not specifying any database name so hive will use its default database. Apache Hive is not designed for online transaction processing and does not offer real-time queries and row level updates and deletes. 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To automatically detect new partition directories added through Hive or HDFS operations: In Impala 2.3 and higher, the RECOVER PARTITIONS clause scans a partitioned table to detect if any new partition directories were added outside of Impala, such as by Hive ALTER TABLE statements or by hdfs dfs or hadoop fs commands. ]table_name[PURGE] IF EXISTS clause: The optional IF EXISTSclause makes the statement succeed whether or not the table exists. DROP TABLE Examples. You can use the below command to drop the table. If you use the DELETE statement to remove all the rows in a table, the table still exists until it is removed with the DROP TABLE statement. If it is an external table then the table entry will delete it from metastore but the data is … Syntax: TRUNCATE [TABLE] table_name [PARTITION partition_spec]; partition_spec: : (partition_column = partition_col_value, partition_column = partition_col_value, ...) TRUNCATE state is used to truncate a table or partitions in a table. It can be a normal table or an external table; Hive treats both in the same manner, irrespective of their types. If PURGE is not specified then the data is actually moved to the .Trash/current directory. hive> DROP DATABASE IF EXISTS userdb; DROP TABLE command in the hive is used to drop a table inside the hive. Its syntax is as follows: DROP DATABASE StatementDROP (DATABASE|SCHEMA) [IF EXISTS] database_name [RESTRICT|CASCADE]; The following queries are used to drop a database. The syntax is as follows: DROP TABLE [IF EXISTS] table_name; Please use ide.geeksforgeeks.org, generate link and share the link here. hive – if exists. Drops the table and all the data associated with it in the Hive metastore. Below are the steps to launch a hive on your local system. DROP table command removes the metadata and data for a particular table. However, the latest version of Apache Hive supports ACID transaction, but using ACID transaction on table with huge amount of data may kill the performance of Hive server. How Does Namenode Handles Datanode Failure in Hadoop Distributed File System? This chapter describes how to drop a table in Hive. Truncate table. For non-Hive tables and partitions, Spark already behaves as if the PURGE option was set, so there's no need to do anything. The DROP TABLE statement in Hive deletes the data for a particular table and remove all metadata associated with it from Hive metastore. Steps and Examples, hive> alter table t drop if exists partition (p=1),partition (p=2) FAILED Execution Error, return code 1 from org.apache.hadoop.hive.ql.exec. (For example, if an abnormal server exit occurs after removal of the table from the storage engine but … DROP TABLE in Hive. What is Schema On Read and Schema On Write in Hadoop? The RECOVER PARTITIONS clause automatically recognizes any … Drop or Delete Hive Partition. ALTER TABLE some_table DROP IF EXISTS PARTITION (year = 2012); This command will remove the data and metadata for this partition. The same limitation exists currently for "ALTER TABLE ... DROP PARTITION" so should probably also be covered by this change. Let us assume std_db is the database created by the user needs to dropped. By using our site, you If PURGE is specified, then data is lost completely. Log In. DROP TABLE Syntax DROP TABLE [IF EXISTS] table_name [PURGE]; DATABSE and SCHEMA can be used interchangeably in Hive as both refer to the same. Below example drops an employee table from Hive metastore. Hive> DROP DATABASE IF EXISTS std_db CASCADE; CASCADE will be used to delete all table… So basically, for the hive drop table to have the data, the data file is a prerequisite. The hive DROP TABLE statement comes with a PURGE option. Also removes the underlying HDFS data files for internal tables, although not for external tables. Syntax: DROP TABLE [IF EXISTS] [db_name. DROP TABLE command in the hive is used to drop a table inside the hive. Apache Hive Installation and Configuring MySql Metastore for Hive, Apache Hive - Getting Started With HQL Database Creation And Drop Database, Apache Hive Installation With Derby Database And Beeline. Deletes the table and removes the directory associated with the table from the file system if the table is not EXTERNAL table. You can use PURGE option to delete data file as well along with partition mentadata but it works only in INTERNAL/MANAGED tables ALTER TABLE table_name DROP [IF EXISTS] PARTITION partition_spec PURGE; External Tables have a two step process to alterr table drop partition + removing file The data is actually moved to the .Trash/Current directory if Trash is configured (and PURGE is not specified). To perform the below operation make sure your hive is running. When you drop a range-, hash-, or list-partitioned table, then the database drops all the table partitions. We will dive deep into table properties in future chapters. If it is an internal table then the table and data will complete delete. It can be a normal table (stored in Metastore) or an external table (stored in local file system); Hive treats both in the same manner, irrespective of their types. The hive DROP TABLE statement comes with a PURGE option. Hive Drop Table - The DROP TABLE statement is used to drop an existing table in a database.The SQL DROP TABLE statement allows you to remove or delete a table from the SQL database. If the client supports it (Hive >= 0.14.0 according to the Hive docs), we should allow that option to be defined. $ DROP TABLE IF EXISTS employee; DROP TABLE [IF EXISTS] table_name [PURGE]; -- (Note: PURGE available in Hive 0.14.0 and later) DROP TABLE removes metadata and data for this table. Drop Database is a statement that drops all the tables and deletes the database. The DROP TABLE statement removes a table definition and all the table's data, metadata, and indexes. Using partitions, we can query the portion of the data. ALTER TABLE ADD PARTITION in Hive. From the other hand when I do the same thing at the impala editor everything works fine. void: dropFunction (String db ... , boolean purge, boolean retainData) Drop one or many partitions in the given table, assuming they exist. Hive DELETE FROM Table Alternative. Hive will remove all of its data and metadata from the hive meta-store. Hive is very much capable such that it can query petabytes of records stored inside the hive table. Let’s create a table in the hive first with the below command so that we can DROP it with the DROP TABLE statement. The syntax of IF EXISTS is as follows: drop table if exists table_name hive – PURGE. Hive will remove all of its data and metadata from the hive meta-store. IF EXISTS can also be useful for dropping tables in unusual circumstances under which there is an entry in the data dictionary but no table managed by the storage engine. DROP TABLE employee; With the help of the below command, all the content of the data table will be removed permanently because I have used the PURGE option with the DROP TABLE command. Drop the specified database, if it exists. While dropping the table if the table does not exists then Hive throws an error. For now we can learn how to add new table property in the hive. Impala "drop table" fails with Hive Metastore exception. The tables in the hive are used for storing data in tabular format(structured). Apache hive is a data warehousing tool that we use to manage our structure data on Hadoop. When you drop a table from Hive Metastore, it removes the table/column data and their metadata. Data is usually moved to .Trash/Current directory if Trash is configured. Drop or Delete Hive Partition You can use ALTER TABLE with DROP PARTITION option to drop a partition for a table. Please write to us at contribute@geeksforgeeks.org to report any issue with the above content. Writing code in comment? Experience. 4. The same limitation exists currently for "ALTER TABLE ... DROP PARTITION" so should probably also be covered by this change. Hive Drop Table - Learn Hive in simple and easy steps from basic to advanced concepts with clear examples including Introduction, Architecture, Installation, Data Types, Create Database, Use Database, Alter Database, Drop Database, Tables, Create Table, Alter Table, Load Data to Table, Insert Table, Drop Table, Views, Indexes, Partitioning, Show, Describe, Built-In Operators, Built-In Functions Drop Table is used to Drop the table from a Hive database. Type: Bug ... Metastore log file shows that "DELETE FROM `PARTITION_KEYS` WHERE `TBL_ID`=?" In addition, we can use the Alter table add partition command to add the new partitions for a table. To use ACID transaction, one must create a table … Please Improve this article if you find anything incorrect by clicking on the "Improve Article" button below. Example 2 - Error that occurs when using DROP TABLE without the IF EXISTS clause You can use ALTER TABLE with DROP PARTITION option to drop a partition for a table. In case if the PURGE option is mentioned the data will be completely lost and cannot be recovered later but if not mentioned then data will move to .Trash/current directory. Details. XML Word Printable JSON. Below is the command to check. jdbc:hive2://>DROP TABLE employee2; jdbc:hive2://>DROP TABLE emp.employee2; jdbc:hive2://>DROP TABLE IF EXISTS employee2 PURGE; Conclusion. If you use the DELETE statement to remove all the rows in a table, the table still exists until it is removed with the DROP TABLE statement. If we want the statement to succeed even if the table is not present then we need to use “IF EXISTS”. DROP TABLE. An exception is thrown if the table does not exist. When you will drop/delete the table form the hive database, the table entry will delete it from hive metastore. Removes an Impala table. The below syntax can be used to delete the database. We use cookies to ensure you have the best browsing experience on our website. Example: For non-Hive tables, as far as I can understand, "PURGE" is the current behavior of Spark. Alter table statement is used to change the table structure or properties of an existing table in Hive. DROP TABLE [IF EXISTS] table_name [PURGE]; Usage of DROP Table command in Hive . If you drop a composite-partitioned table, then all the partitions and subpartitions are also dropped. Export. For non-Hive tables, as far as I can understand, "PURGE" is the current behavior of Spark. When you drop a table from Hive Metastore, it removes the table/column data and their metadata. In case of an external table, only the associated metadata information is removed from the metastore database. Create an external table to store the CSV data, configuring the table so you can drop it along with the data. DROP TABLE IF EXISTS Vehicles PURGE; CREATE TABLE Vehicles (route VARCHAR (3), deviation SMALLINT) COMMENT ' 1-7.05.2019 public transportation vehicles (Olsztyn/Poland)' PARTITIONED BY(day TINYINT) CLUSTERED BY (route) INTO 4 BUCKETS: STORED AS ORC; INSERT OVERWRITE TABLE Vehicles PARTITION(day) Parameters: db ... Returns the user name which is used as owner for Hive table. If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to contribute@geeksforgeeks.org. When you delete a file/folder it is not removed permanently . Let us assume that the database name is userdb. We can drop the table in hive with simple SQL like a command. Types of Drop Table in Hive. version When I have a table at my sqoop schema and want to delete it, I go to HIVE editor (through HUE) and key in the following command DROP TABLE IF EXISTS schemaName.tblName PURGE; After that the table disappeared form the gui of HUE (sqoop table list, metastore list) but the actual files of the table were not deleted from the HDFS. CREATE EXTERNAL TABLE IF NOT EXISTS names_text( a INT, b STRING) ROW FORMAT DELIMITED FIELDS TERMINATED BY ',' STORED AS TEXTFILE LOCATION 's3a://andrena' TBLPROPERTIES ('external.table.purge'='true'); hive (maheshmogal)> ALTER TABLE emp SET TBLPROPERTIES('auto.purge'='true'); OK Time taken: 0.313 seconds hive (maheshmogal)> Dropping Table In Hive. The DROP TABLE statement removes a table definition and all the table's data, metadata, and indexes. There's currently code that explicitly disables the "PURGE" flag when dropping a table: That flag is necessary in certain situations where the table data cannot be moved to the trash (which will be tried unless "PURGE" is requested). Sum of even and odd numbers in MapReduce using Cloudera Distribution Hadoop(CDH), Difference Between Hadoop 2.x vs Hadoop 3.x, Hadoop - Schedulers and Types of Schedulers, Hadoop Streaming Using Python - Word Count Problem, Write Interview In this article, I am using DATABASE but you can use SCHEMA instead. Hive support for PURGE was added in 0.14 (for tables) and 1.2 (for partitions), so the code reflects that: trying to use the option with older versions of Hive … If the client supports it (Hive >= 0.14.0 according to the Hive docs), we should allow that option to be defined. In this article, we are going to see how to drop tables in the hive, what happens when the table is dropped and all things related to the drop table in the hive. DROP DATABASE was added in Hive 0.6. Why this is happened & how can I drop/remove a table from hive … Drop Table Statement. See your article appearing on the GeeksforGeeks main page and help other Geeks.
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