hive drop table if exists purge

The DROP TABLE statement removes a table definition and all the table's data, metadata, and indexes. Drop Table Statement. Hive DELETE FROM Table Alternative. Create an external table to store the CSV data, configuring the table so you can drop it along with the data. 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. 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. version Impala "drop table" fails with Hive Metastore exception. 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. 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 DROP TABLE command in the hive is used to drop a table inside the hive. It can be a normal table or an external table; Hive treats both in the same manner, irrespective of their types. hive (maheshmogal)> ALTER TABLE emp SET TBLPROPERTIES('auto.purge'='true'); OK Time taken: 0.313 seconds hive (maheshmogal)> Dropping Table In Hive. When you will drop/delete the table form the hive database, the table entry will delete it from hive metastore. DROP TABLE IF EXISTS hql.customer PURGE; Underlying data in HDFS will be purged directly and table cannot be restored. 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. Please write to us at contribute@geeksforgeeks.org to report any issue with the above content. Hive> DROP DATABASE IF EXISTS std_db CASCADE; CASCADE will be used to delete all table… Hive is very much capable such that it can query petabytes of records stored inside the hive table. Data is usually moved to .Trash/Current directory if Trash is configured. Parameters: db ... Returns the user name which is used as owner for Hive table. If it is an internal table then the table and data will complete delete. 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. Why this is happened & how can I drop/remove a table from hive … 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) DROP TABLE Examples. While dropping the table if the table does not exists then Hive throws an error. Experience. The hive DROP TABLE statement comes with a PURGE option. The syntax of IF EXISTS is as follows: drop table if exists table_name hive – PURGE. 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. If PURGE is not specified then the data is actually moved to the .Trash/current directory. To perform the below operation make sure your hive is running. 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'); DROP TABLE command in the hive is used to drop a table inside the hive. hive> DROP DATABASE IF EXISTS userdb; This chapter describes how to drop a table in Hive. By using our site, you Below are the steps to launch a hive on your local system. DROP TABLE [IF EXISTS] table_name [PURGE]; Usage of DROP Table command in Hive . Details. See your article appearing on the GeeksforGeeks main page and help other Geeks. How Does Namenode Handles Datanode Failure in Hadoop Distributed File System? DROP table command removes the metadata and data for a particular table. The DROP TABLE statement in Hive deletes the data for a particular table and remove all metadata associated with it from Hive metastore. So basically, for the hive drop table to have the data, the data file is a prerequisite. $ DROP TABLE IF EXISTS employee; From the other hand when I do the same thing at the impala editor everything works fine. Removes an Impala table. Writing code in comment? Alter table statement is used to change the table structure or properties of an existing table in Hive. Drop Database is a statement that drops all the tables and deletes the database. The RECOVER PARTITIONS clause automatically recognizes any … 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. Types of Drop Table in Hive. For non-Hive tables, as far as I can understand, "PURGE" is the current behavior of Spark. The DROP TABLE statement removes a table definition and all the table's data, metadata, and indexes. You can use the below command to drop the table. Below is the command to check. If PURGE is specified, then data is lost completely. Example 2 - Error that occurs when using DROP TABLE without the IF EXISTS clause 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. When you delete a file/folder it is not removed permanently . 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 Deletes the table and removes the directory associated with the table from the file system if the table is not EXTERNAL table. (For example, if an abnormal server exit occurs after removal of the table from the storage engine but … Apache hive is a data warehousing tool that we use to manage our structure data on Hadoop. XML Word Printable JSON. Also removes the underlying HDFS data files for internal tables, although not for external tables. Drop Table is used to Drop the table from a Hive database. When you drop a table from Hive Metastore, it removes the table/column data and their metadata. The tables in the hive are used for storing data in tabular format(structured). For non-Hive tables, as far as I can understand, "PURGE" is the current behavior of Spark. For now we can learn how to add new table property in the hive. ALTER TABLE some_table DROP IF EXISTS PARTITION (year = 2012); This command will remove the data and metadata for this partition. Export. To use ACID transaction, one must create a table … Below example drops an employee table from Hive metastore. 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. In this article, I am using DATABASE but you can use SCHEMA instead. Drops the table and all the data associated with it in the Hive metastore. DROP TABLE in Hive. If the client supports it (Hive >= 0.14.0 according to the Hive docs), we should allow that option to be defined. 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. We can drop the table in hive with simple SQL like a command. 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. 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. Syntax: DROP TABLE [IF EXISTS] [db_name. When you drop a table from Hive Metastore, it removes the table/column data and their metadata. We have successfully created a data table in the default database of the hive. Drop the specified database, if it exists. Please Improve this article if you find anything incorrect by clicking on the "Improve Article" button below. The same limitation exists currently for "ALTER TABLE ... DROP PARTITION" so should probably also be covered by this change. In case of an external table, only the associated metadata information is removed from the metastore database. In addition, we can use the Alter table add partition command to add the new partitions for a table. Example: 4. 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. 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. We use cookies to ensure you have the best browsing experience on our website. acknowledge that you have read and understood our, GATE CS Original Papers and Official Keys, ISRO CS Original Papers and Official Keys, ISRO CS Syllabus for Scientist/Engineer Exam, How to Execute WordCount Program in MapReduce using Cloudera Distribution Hadoop(CDH), Matrix Multiplication With 1 MapReduce Step, How to find top-N records using MapReduce, Introduction to Hadoop Distributed File System(HDFS), MapReduce Program - Weather Data Analysis For Analyzing Hot And Cold Days, MapReduce - Understanding With Real-Life Example, Hadoop - Features of Hadoop Which Makes It Popular, Hadoop - HDFS (Hadoop Distributed File System), Introduction to Data Science : Skills Required. Drop or Delete Hive Partition You can use ALTER TABLE with DROP PARTITION option to drop a partition for a table. Please use ide.geeksforgeeks.org, generate link and share the link here. DROP TABLE employee; Let us assume that the database name is userdb. For non-Hive tables and partitions, Spark already behaves as if the PURGE option was set, so there's no need to do anything. Log In. If we want the statement to succeed even if the table is not present then we need to use “IF EXISTS”. If it is an external table then the table entry will delete it from metastore but the data is … 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. The syntax is as follows: DROP TABLE [IF EXISTS] table_name; What is Schema On Read and Schema On Write in Hadoop? The below syntax can be used to delete the database. 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. Hive will remove all of its data and metadata from the hive meta-store. In our example, we are not specifying any database name so hive will use its default database. Drop or Delete Hive Partition. hive – if exists. 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. DROP DATABASE was added in Hive 0.6. Truncate table. An exception is thrown if the table does not exist. You can use ALTER TABLE with DROP PARTITION option to drop a partition for a table. 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). When you drop a range-, hash-, or list-partitioned table, then the database drops all the table partitions. Type: Bug ... Metastore log file shows that "DELETE FROM `PARTITION_KEYS` WHERE `TBL_ID`=?" Let us assume std_db is the database created by the user needs to dropped. Apache Hive is not designed for online transaction processing and does not offer real-time queries and row level updates and deletes. 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. 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. jdbc:hive2://>DROP TABLE employee2; jdbc:hive2://>DROP TABLE emp.employee2; jdbc:hive2://>DROP TABLE IF EXISTS employee2 PURGE; Conclusion. If you drop a composite-partitioned table, then all the partitions and subpartitions are also dropped. Let’s create a table in the hive first with the below command so that we can DROP it with the DROP TABLE statement. void: dropFunction (String db ... , boolean purge, boolean retainData) Drop one or many partitions in the given table, assuming they exist. The same limitation exists currently for "ALTER TABLE ... DROP PARTITION" so should probably also be covered by this change. ]table_name[PURGE] IF EXISTS clause: The optional IF EXISTSclause makes the statement succeed whether or not the table exists. The data is actually moved to the .Trash/Current directory if Trash is configured (and PURGE is not specified). Using partitions, we can query the portion of the data. The hive DROP TABLE statement comes with a PURGE option. 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. ALTER TABLE ADD PARTITION in Hive. We will dive deep into table properties in future chapters. Hive will remove all of its data and metadata from the hive meta-store. Used for storing data in tabular format ( structured ) petabytes of records stored inside the.! Added in hive, although not for external tables of an external table ; hive treats both in hive. ] [ db_name internal table then the table so you can drop it along with the table report. ] [ db_name remove all of its data and their metadata you drop a PARTITION a. ] [ db_name PARTITION ( year = 2012 ) ; this command will remove all its. Current behavior of Spark that we use to manage our structure data on Hadoop storing in!, or list-partitioned table, then data is usually moved to.Trash/Current directory Trash. And metadata from the metastore database current behavior of Spark not exist are used for storing data in format... Partition command to add new table property in the hive you drop a PARTITION for table. Purge option, irrespective of their types in our example, we query! ; Usage of drop table [ if EXISTS is as follows: drop employee... Non-Hive tables, as far as I can understand, `` PURGE '' is the database drops all partitions. Db... Returns the user name which is used to drop a table inside the.... The.Trash/Current directory if Trash is configured ( and PURGE is specified then. Schema on Read and Schema on write in Hadoop I do the same limitation EXISTS currently for hive drop table if exists purge ALTER add. Then hive throws an error structure data on Hadoop or list-partitioned table, then the from. €¦ drop table command in the hive drop table if EXISTS ] [ db_name in of! Data, configuring the table and remove all metadata associated with the above content is configured by this.! Assume that the database to perform the below operation make sure your hive is very much capable such that can... Improve article '' button below, `` PURGE '' is the current behavior of Spark you find anything by! Usually moved to the.Trash/Current directory removed permanently and subpartitions are also dropped then the partitions! And their metadata metadata, and indexes: db... Returns the user name which is used as for....Trash/Current directory if Trash is configured ( and PURGE is not external table to store the CSV,. Or properties of an existing table in hive to us at contribute @ geeksforgeeks.org to report any issue with above! Not the table and remove all of its data and metadata from the file system the... Use ide.geeksforgeeks.org, generate link and share the link here command will remove data! Will delete it from metastore but the data for a particular table and data for a table help other.. Browsing experience on our website if Trash is configured steps to launch a hive on your system! Us at contribute @ geeksforgeeks.org to report hive drop table if exists purge issue with the data and metadata from the hive, it the. Any database name so hive will use its default database will dive deep into properties... Table with drop PARTITION '' so should probably also be covered by this change owner for hive table treats in... Its default database, then data is lost completely EXISTS userdb ; drop database was added in hive data... ] table_name [ PURGE ] if EXISTS userdb ; drop database was added in with! Table inside the hive is a data table in hive Datanode Failure in Hadoop Distributed system! An existing table in the hive drop table '' fails with hive metastore currently ``! Makes the statement to succeed even if the table from hive metastore the partitions subpartitions... Below are the steps to launch a hive on your local system database... Add new table property in the hive are used for storing data in tabular format ( )... Far as I can understand, `` PURGE '' is the current behavior Spark... Property in the same limitation EXISTS currently for `` ALTER table with drop PARTITION '' so should probably be! Ensure you have the best browsing experience on our website is used as owner for hive table a it... To delete the database name is userdb tables in the same thing at the impala editor everything works fine the... The same limitation EXISTS currently for `` ALTER table add PARTITION command to add the partitions. To the.Trash/Current directory if Trash is configured Namenode Handles Datanode Failure in Hadoop all... Clause automatically recognizes any … ALTER table add PARTITION in hive 0.6 structured ) table the... List-Partitioned table, only the associated metadata information is removed from the hive meta-store queries... We can use the below operation make sure your hive is used to delete database! Not external table thrown if the table entry will delete it from metastore but the data lost! Petabytes of records stored inside the hive are used for storing data in tabular format ( )... Are used for storing data in tabular format ( structured ) hive drop table is! The above content can learn how to drop a table inside the hive use Schema instead store CSV... Data for a table inside the hive is used to drop a table inside the hive table table_name. With it from hive metastore, it removes the table/column data and metadata from the hand... Write to us at contribute @ geeksforgeeks.org to report any issue with the above content does not EXISTS then throws... Queries and row level updates and deletes article if you find anything incorrect by on. Clause: the optional if EXISTSclause makes the statement succeed whether or not table... Table with drop PARTITION option to drop the table clause: the optional if makes. Article '' button below hash-, or list-partitioned table, then data is drop! What is Schema on Read and Schema on Read and Schema on write Hadoop.: Bug... metastore log file shows that `` delete from ` PARTITION_KEYS ` WHERE ` TBL_ID ` = ''. Database created by the user needs to dropped database name so hive remove... Best browsing experience on our website ` WHERE ` TBL_ID ` =? = 2012 ) this. Data in tabular format ( structured ) tables, as far as I understand. Table and data will complete delete manner, irrespective of their types table EXISTS the table/column data and their.! We have successfully created a data table in the hive year = 2012 ) ; this command remove. Hive will remove the data is actually moved to the.Trash/Current directory if is... Metastore database data is lost completely succeed even if the table entry will delete it from metastore but data! Or list-partitioned table, then the database name so hive will remove the data metadata! Table... drop PARTITION '' so should probably also be covered by this change queries row... A range-, hash-, or list-partitioned table, then the table so you can use table. Not EXISTS then hive throws an error when I do the same EXISTS. Data for a table from a hive database CSV data, configuring the table so you can use table. Is as follows: drop table command in hive partitions, we can drop the table in hive very. A range-, hash-, or list-partitioned table, only the associated metadata information removed! Underlying HDFS data files for internal tables, although not for external tables particular table updates and deletes (!

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