Alter table drop partition hive. So there is a shortcut to drop columns from a hive table.

• Alter table drop partition hive exec. @Reddy The commands below work: Hive does not accept subquery in that DDL clause, but this works: ALTER TABLE myTable DROP PARTITION (date < 'date1') , PARTITION (date >'date2'); It needs literals for 'date1' and 'date2'. Skip to the content. partition. Make table EXTERNAL, DROP, CREATE with new location, run MSCK REPAIR: alter table test_table SET TBLPROPERTIES('EXTERNAL'='TRUE'); drop table test_table; create ADD AND DROP PARTITION ADD PARTITION. Have you defined both yop and mop as part of your create table command. INSERT INTO zdb. alter table table_name drop partition(rep_date < from_unixtime(unix_timestamp(),'yyyy-MM-dd')); This returns an error: Skip to main content. Hive table partition is a way to split a large table into smaller logical tables based on one or more partition keys. partition=true; set hive. ALTER TABLE table_name SET TBLPROPERTIES table_properties; table_properties: : (property_name = property_value, property_name = property_value, ) And your comment. 2. Applies to: Databricks SQL Databricks Runtime Adds, drops, renames, or recovers partitions of a table. In my case worked ALTER TABLE This is overkill when we want to add an occasional one or two partitions to the table. the table is partitioned by the column "day" containing the time the data was transferred to hive in the Have a script or so that send yesterday's value to the the above alter table drop partition command and use = as < or > doesnt work in hive – K S Nidhin. ALTER TABLE table_identifier DROP [ IF EXISTS ] partition_spec [PURGE] Now if . See examples of partitioning on single or multiple columns and how to exclude partition We will use this step’s command if we want to drop some specific partitions from the table. how to drop partition metadata from hive, when partition is drop by using alter drop command. You can update a Hive partition by, for example: ALTER TABLE logs PARTITION(year = 2012, month = 12, day = 18) SET LOCATION 'hdfs://user/darcy/logs/2012/12/18'; This command does not move the old data, nor does it You can use ALTER TABLE DROP PARTITION to drop a partition for a table. You need to use Linux/ Unix to set the variable for the DROP PARTITION date and use it in the ALTER TABLE statement. hive> CREATE TABLE `order_items`( > `order_item_id` int, > `order_item_order_id` int, > `order_item_order_date` So, I figured out the problem: When Spark creates partitions it creates these using user permissions, so in my case for the user dude and the group hdfs. usage . 13. The drop partition will actually move data to the . At work we receive a new file each day that we transfer to hive. mode=nonstrict; insert overwrite table new_table partition(C) select --list columns without deleted from old_table; And finally, after dropping old table, you can rename new one using ALTER TABLE table_name RENAME TO 1) Your table is partitioned that means each existing partition also needs to be updated with new column type. These rows for deletion matches certain conditions, so entire partitions can not be dropped in order to do so. for every partition or in short you can run When using external hive tables, is there a way where I can delete the data within the directory but retain the partitions via a query. The name must be unique within the table. Problem: The newly added columns will show up as null values on the data present in existing partitions. However, if I drop and add the partition, I see the correct data. . g: 1204,1203,1204 When I tried dropping the partition I by mistake typed only dept_key and not "dept_key_partition" this in turn dropped all my partition drop query alter table dept_details drop partition (dept_key=12), its a very strange issue which I am facing. alter table table_name drop PARTITION(update_date >= 20230310); alter table table_name drop PARTITION(update_date >= 20230310, update_date <= 20230320); 参考链接： hive删除分区部分数据 参考链接： Hive分区 To drop a partition from a Hive table, this works: ALTER TABLE foo DROP PARTITION This task is to implement ALTER TABLE DROP PARTITION for all of the comparators, < > <= >= <> = != instead of just for =. You can paste the syntax of create table command by running show create table alt_part and paste the output. my_table; However, while this does move the table's location, the table is empty. The new table properties in the REPLACE TABLE command will be merged with any existing table properties. std_details table. Come to your problem. test_table drop partition (date='${date}'); – kalpesh Commented Jan 24, 2020 at 7:03 The link demonstrates that what is being assigned to a variable is a text, not a query/expression result. Within the spark job when I try to do. If, however, new partitions are directly added to HDFS (manually by hadoop fs -put command), the metastore will not be aware of these partitions. Conversely, if a table has NO_DROP enabled then partitions may be dropped, but with NO_DROP CASCADE partitions cannot be dropped either unless the drop partition command specifies IGNORE PROTECTION. Here is an example. ALTER TABLE table_name DROP [IF 1st approach will work. sparksession. ALTER TABLE table_name DROP IF EXISTS PARTITION. If you are not the owner of the table, then you need the DROP ANY TABLE privilege in order to use the drop_table_partition or truncate_table_partition clause. trash folder. 0). Interestingly, neither hive nor spark are users in the group hdfs; dude is also not part of that group. Steps as below. why - This will recover all the partitions in the directory of a table and The Data Definition Language (DDL) for ALTER TABLE can be found here. /file. Eg. First, we can check what are the columns of our table by describe <table_name>; command. I would like to illustrate more into it. MSCK REPAIR TABLE db. Follow edited Feb 7, 2015 at 23:53. A table in Hive consists of rows and columns, similar to a table in a relational database. Hive will not create the partitions for you this way. If you need these to be dynamic then you can use ' --hivevar date1=xxxxx ' for So there is a shortcut to drop columns from a hive table. By running ALTER TABLE DROP PARTITION you are only deleting the data and metadata for the matching partitions, not the partitioning of the table itself. Just replace the external hdfs file with whichever new file you want (the structure of the replaced file should be the same) and when you do a select * of the previous table, you will notice that it will have the new data and not the old one. Rename Dropping a partition can also be performed using ALTER TABLE tablename DROP jdbc:hive2://127. To automatically detect new partition directories added through Hive or HDFS operations: In Impala 2. Follow answered Sep 24, 2016 at 0:59. Below Uses of Hive ALTER TABLE Command. Improve this question. Syntax. ALTER TABLE RECOVER PARTITIONS is the command that is widely used in Hive to refresh partitions as new partitions are directly added to the file system You can update a Hive partition by, for example: ALTER TABLE logs PARTITION(year = 2012, month = 12, day = 18) SET ALTER TABLE logs DROP IF EXISTS It's simple usually to change/modify the exesting table use this syntax in Hive. Syntax This is a table in hive with partitions. For type changes or renaming columns in Delta Lake see rewrite the data. Fast access to the data; Provides the ability to perform an operation on a smaller dataset; Create Hive Partition Table. alter table table_name drop partition (partition_col<val); . And just to delete data and keep the table structure, use truncate command. ALTER TABLE DROP statement drops the partition of the table. Why do I need to drop and add the partition again after refreshing the Hive metastore? Also, how does MSCK REPAIR TABLE test differ from ALTER TABLE test DROP PARTITION (date='2024') followed by ALTER TABLE test ADD PARTITION (date='2024'), and is one method preferred over the other? Multiple partitions can be dropped with the following syntax: alter table historical_data drop partition (year = 1996 and month between 1 and 6); Please see our ALTER TABLE Statement documentation for more details, the multiple partition drop can be found in section: To drop or alter multiple partitions. To change the comment on a table, you can also use COMMENT ON. field_name. col. The table is partitioned by multiple columns and one of the columns (circle) has spaces in its values(eg "Punjab and Rajasthan"). table In Hive, a partitioned table stores its data in separate subdirectories for each unique combination of partition column values. If you need these to be dynamic then you can use ' --hivevar date1=xxxxx ' for I have 2 types of value in the partition column of string datatype: yyyyMMdd yyyy-MM-dd E. 1+42. To alter a STREAMING TABLE, use ALTER STREAMING TABLE. ALTER TABLE test_tbl REPLACE COLUMNS(ID STRING,NAME STRING,AGE STRING); you have to give the column names which you want to keep in the table Apache Hive ALTER TABLE Command, Syntax, Examples, Rename Hive Table , Add new column to Hive Table, Change Hive Table Column name and Type, Add and Drop Partition using ALTER TABLE Command. 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. ALTER TABLE test_tbl REPLACE COLUMNS(ID STRING,NAME STRING,AGE STRING); you have to give the column names which you want to keep in the table @Vin Yes, you can do that in spark-sql. 56. Instead, per HIVE-1941, we will require users to explicitly declare view partitioning as part of CREATE VIEW, and explicitly manage partition metadata via ALTER VIEW ADD|DROP PARTITION. Partitioning divides a table into sections based on the values of specific columns, such as date, city, and department. This removes the data and metadata for this partition. The table must be in your own schema, or you must have ALTER object privilege on the table, or you must have ALTER ANY TABLE system privilege. Here, we are going to drop partition 2008, 2009 and 2010 only. I am facing a problem with hive default partition (null partition) in hive. 0+ as part of HIVE-11745. 0 and later) 你可以使用 ALTER TABLE DROP PARTITION 删除表的分区。 Hive - Alter Table. Dropping a partition: drop old table and rename new one; Like this: set hive. 56 ALTER TABLE staging_event DROP PARTITION ( did < Hive ALTER TABLE * DROP PARTITION in hive-0. So, only way is to - create a new table with new partitioned column type. Create new external table using partitioning; Insert into new table by selecting from the old table; Drop the new table (external), only table will be dropped but data will be there; Drop the old table; Create the table with original name by pointing to the location under step 2 ALTER TABLE table_name DROP [IF EXISTS] PARTITION partition_spec PURGE; But for External tables have a two-step process to alter table drop partition + removing file. This will be used with the DROP TABLE statement. Exchanging multiple partitions is supported in Hive versions 1. Scenario: Trying to add new columns to an already partitioned Hive table. This allows all of the use cases to be satisfied (while placing more burden on the user, and taking up more metastore space). For some reason the group that hive and spark belong to is called hadoop on our cluster. alter table test drop partition (date_dim>='2014-07-11',date_dim<='2014-07-30') I hope these 2 partitions be deleted: Is there anyway to make hive drop partition as I wish? hive; Share. You can configure using either one // If there is always only one partition alter table part_t drop partition (year=2003,month=1); // If there are multiple partitions, ADD AND DROP PARTITION ADD PARTITION. changes in your hive server, otherwise this operation may fail, throws an exception like The following columns have types incompatible with the existing columns in their respective positions. Make table EXTERNAL, DROP, CREATE with new location, run MSCK REPAIR: alter table test_table SET TBLPROPERTIES('EXTERNAL'='TRUE'); drop table test_table; create Try with alter table id drop partition(cl="cl=18"); (or) by enclosing partition value with single quotes(') also. 0. g. metastore. 6,206 16 16 I'm looking for a way to drop partitions in relation to the current day. incompatible. I don't understand very well the difference between add a column with CASCADE or RESTRICT, in Hive documentation I can see: The CASCADE|RESTRICT clause is available in Hive 1. Eg: If there are partitions for year 2018 and month 10 and before that. How do I drop a column of a partiotioned table in Hive? I have an external table with 4 columns, for example: column_A column_B column_C dt_test - partition I have to drop the column_C, so, I'm try Hive Alter 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 Although I agree with pensz, a slight alteration, you need not drop the table. I will explain the situation briefly here. – K S Nidhin. txt 30/Mar/12 21:48 34 kB Because I noticed that since it was recreated, it need to resync the partitions as below and this results in long time taken as it need to run the ALTER TABLE for all partitions. Simply using a partition_options clause with ALTER TABLE on a partitioned table repartitions the table according to the partitioning scheme defined by the partition_options. The Data Definition Language (DDL) for ALTER TABLE can be found here. set date = 20161201; Alter table test_schema. Additional Prerequisites for Partitioning Operations. Includes step-by-step instructions and examples. Rename a Table. You can do this by setting up below property and then run alter statement. Similarly, multiple partitions for each class can be set by using ADD PARTITION. You can also manually update or drop a Hive partition directly on HDFS using Hadoop commands, if you do so you need to run the MSCK command to synch up HDFS files with Hive Metastore. In this article, we will discuss several helpful commands for altering, updating, and dropping partitions, as well as managing the data associated with Hive tables that store data in Parquet format Using Hive Partition you can divide a table horizontally into multiple sections. You may need to do this as the hive or hdfs user, depending on how your permissions are set up. As a workaround, you can use the AWS Glue API GetPartitions I have a hive table where partition exists on one of the date column, but date column is stored as INT in the format YYYYMMDD. show partitions table table_name; then rename the faulty partition to some other name in correct format of your partition. ALTER TABLE some_table DROP IF EXISTS PARTITION(year = 2012); This command will remove the data and metadata for this partition. Are there any internal/performance difference between the below two statements for creating static partitioning in hive, I have tried both ways and both of them are working without any issues It probably left from your previous table load. The RECOVER This page shows how to create, drop, and truncate Hive tables via Hive SQL (HQL). If it's a managed table, then both will be removed. sandeep rawat sandeep rawat. This clause always begins with PARTITION BY, and follows the same syntax and other rules as apply to the partition_options clause for CREATE TABLE (for more detailed information, see Section Make your table external (in case you define this as a non-external table). Follow the article below to install Hive on Windows 10 via WSL if you don't have available available Hive database to practice Hive SQL: Apache Hive 3. alter table vtc4 The ALTER TABLE statement changes the structure or properties of an existing Impala table. I have 2 types of value in the partition column of string datatype: yyyyMMdd yyyy-MM-dd E. Below are the most common uses of the ALTER TABLE command: You can rename table and column of existing Hive tables. You alter command actually looks like alter table rerank_session_features drop if exists partition (data_date<'select date_sub(date '2019-10-21',19)');. When a partition metadata retention period is specified, Hive will drop Use a method to pull all partitions you want to drop and pass the same into a string and pass the string as a command Initial_string="alter table t drop if exists" As soon as tables are created in the Hive metastore, they are surfaced and available to query in the Unity Catalog federated catalog. You can use the ALTER TABLE REPLACE statement to drop a column. The Exchange Partition feature is implemented as part of HIVE-4095. alter table tbl_nm drop if exists partition (col = ‘value’ , . You can then add dynamic partitions with something REFRESH the table only when I add new data through HIVE or HDFS commands ?That is when I am doing insert into through impala-shell no need for refreshing ?. 2) Overwrite table with required row data. We should use an ALTER TABLE query in such cases. Introduction to Partitioned Tables My understanding is that there is no way from Hive to remove partitions based on missing hdfs directories. 3. Drop the partitions -- when you drop the partitions, data pertained to the partitions will also be dropped as now this table is managed table . If the table is cached, the command clears cached data of the table and all its dependents that refer to it. hql and its contents are: alter. Mark as New; Bookmark; Subscribe; Mute; Subscribe to RSS Feed; Permalink; Print; i am trying to delete a null/HIVE_DEFAULT_PARTITION in from hive external table and also from HDFS directory but i couldn't delete it . ALTER TABLE tableName DROP PARTITION (date >='20190410', date <='20190415'); Learn how to drop a partition from a Hive table with ALTER TABLE. Drop the partitions why - this internally clears up any partition information in the metadata only as this is an external table; ALTER TABLE <table_name> DROP IF EXISTS PARTITION . Syntax An ALTER TABLE command on a partitioned table changes the default settings for future partitions. Let's say you have already run alter Hive provides us the functionality to perform Alteration on the Tables and Databases. Just create a table partitioned by the desired partition key, then execute insert overwrite table from the external table to the new partitioned table (setting hive. Migrating tables in Avro, Parquet, or ORC (Non-ACID) format to Iceberg; Reading the schema of a table. Alternatively remofe those partition folders from HDFS manually, then run MSCK REPAIR – leftjoin. test (col1 STRING, col2 STRING) PARTITIONED BY ALTER TABLE. You cannot change the partitioning scheme on a Hive table. How to recover partitions in easy fashion. Let’s say we have a hive table. This division happens based on a partition key which is just a column in. i have recreated the scenario on end and able to drop the partitions with special characters without using any hex. But for EXTERNAL tables it does not drop data in the filesystem. partition = true; ALTER TABLE table_name PARTITION (partition_column) CHANGE COLUMN old_col new_col data_type; Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about your product, service or employer brand; OverflowAI GenAI features for Teams; OverflowAPI Train & fine-tune LLMs; Labs The future of collective knowledge sharing; About the company Finally, on Hive, transform your table into a EXTERNAL table just to clean its metadata faster, since on the previous step you already deleted its data: ALTER TABLE tablename SET TBLPROPERTIES('EXTERNAL'='TRUE'); ALTER TABLE tablename DROP PARTITION( ALTER TABLE tablename SET TBLPROPERTIES('EXTERNAL'='FALSE'); Is there any way to skip Trash while dropping a partition using the command below from a Managed Table in Hive? ALTER TABLE &lt;table&gt; DROP PARITION (&lt;partition_name&gt;) Similar to what we ALTER TABLE db. insert into the new table from old table. The RECOVER Drop or Delete Hive Partition. there are partition column values 20200301, 2020-03-05, 2020-05-07, 20200701, etc. I already have a Hive partitioned table. Related Articles Altering a table while keeping Iceberg and Hive schemas in sync; Altering the partition schema (updating columns) Altering the partition schema by specifying partition transforms; Truncating a table / partition, dropping a partition. 1 Installation on Windows 10 using Windows Subsystem for Linux ALTER TABLE <table_name> ADD COLUMNS . Ask Question Asked 8 years, 9 months ago. Drop the table. 1. Allow tables to be defined with Hive semantics Dropping partitioned tables is similar to dropping nonpartitioned tables. I have a table in Hive which I would like to drop its partition keys for later using other partition keys. If the table is cached, the command alter table partition_t drop if exists partition (y=20160922 ); then run hive -v -f . 0. ALTER TABLE ADD statement adds partition to the partitioned table. Alteration on table modify’s or changes its metadata and does not affect the actual data available inside the Hive - Partitioning - Hive organizes tables into partitions. mode=nonstrict). sh. Altering the Hive table partitions by reducing the However, if I drop and add the partition, I see the correct data. Tables in Hive are organized into databases and can be managed and queried using the Hive Query Language (HQL), which is similar to SQL. The name of the column to be added. t. 7. mkdir Hive stores a list of partitions for each table in its metastore. Reply. You can think of it this way - Hive stores the data by creating a folder in hdfs with partition column values - Since if you trying to alter the hive partition it means you are trying to change the whole directory structure and data of hive table which is not ALTER TABLE orders DROP PARTITION (dt = '2014-05-14', country = 'IN'), PARTITION (dt = '2014-05-15', country = 'IN'); Notes. You have the right syntax for adding the column ALTER TABLE test1 ADD COLUMNS (access_count1 int);, you just need Do you want dynamic or static partitions? If the table is created with option PARTITIONED BY it will be partitioned. Now, we will learn how to drop some partition or add a new partition to the table in hive. SET hive. Alter Table my_table Drop Partition (date_year, date_month); Alter Table my_table Add Partition (new_col); But as I said earlier both are failing me. Alter Table The table must be configured to automatically synchronize partition metadata with directories or objects on a file system. If you must keep the table partitioned externally Alter hive table add or drop column And this question also suggests same, but users report similar problem to mine, Drop column of hive table stored as orc Am I doing something wrong, or do I just need to copy to a new table? If you want to delete all existing partitions and keep only the new month data, you can use DROP PARTITION command with comparators. Hive> ALTER TABLE std_details ADD PARTITION (std_class=’1’); Once the above statement successfully executed, the partition added to std_db. Among several Hive DDL Commands, here I will be covering the most commonly used DDL commands. DDL commands are used to create databases, tables, modify the structure of the table, and drop the database and tables e. Dropping a partition: 1. 0, and 2. ALTER TABLE table_name CHANGE old_col_name new_col_name new_data_type Here you can change your column name and data type at a time. We divided tables into partitions using Apache Hive. ALTER TABLE command can be used to perform alterations on the tables. In the comments @libjack mentioned a point which is really important. If a particular property was already set, this overrides the old value with the new one. This task assumes you created a partitioned external table named emp_part that stores partitions outside the warehouse. You really cant. Example: DROP SCHEMA hql CASCADE; Output: OK Install Hive database. Syntax Before you proceed make sure you have HiveServer2 started and connected to Hive using Beeline. hql. 2. Attachments. Cloudera Community; date=2022-02-22 | +-----+ alter table mdatetest drop partition (`date`="2022-02-22"); View solution in original post . Created on ‎03-15-2017 09:01 PM - edited ‎09-16-2022 04:15 AM. In this case you can drop the table without removing the data in the directories. Hive is unique in that it will let you define schema on read, altering the definition is just altering the definition it's not changing the data only the table definition. The existing table properties will be updated if changed else they are preserved. You need to recreate the table structure. For further help regarding hive ql, check language manual of hive . sql(""" alter table table_name drop In this post let us learn how to drop partition in hive using examples . Anyway, that means hive You really cant. alter table partition_t drop if exists partition. Ok. When the command is executed, the source table's partition I've created a hive table with two partition columns say col 1 and col2, now for some analytical purpose I wish to delete the col2 partition. Kara. So, I have used the following command to truncate the table : hive> truncate table abc; But, it is throwing me an er Skip to main content. But it will not apply to existing partitions, unless that specific command supports the CASCADE option -- but that's not the case for SET SERDEPROPERTIES; compare with column management for instance. I need to drop partitions keeping last If the hive table is external then the drop partition will only remove the reference in the metastore, leaving the filesystem data intact. Contributor. After creating a partitioned table, Hive does not update metadata about corresponding objects or directories on the file system that you add or drop. If any partition in a table has NO_DROP enabled, the table cannot be dropped either. Let’s create a partition table and load data from the CSV file. Partition columns creates physical folders to partition & store the data. kindly help figure - 336688. Partitioning is defined when the table is created. This can also be used for deleting certain partitions. The location of parquet file is in Amazon S3. there are partition column values 20200301, 2020-03-05, 2020-05-07, 20200701, We can't add __HIVE_DEFAULT_PARTITION__(as this is an reserved key word in hive) to the hive table but we can solve this issue using workaround. If you don't want to change col_name simply makes old_col_name and new_col_name are same. ALTER TABLE table_name DROP [IF EXISTS] PARTITION partition_spec; hdfs dfs -rm -r <partition file path> I hope this gives some insights here. Solved: Hi guys, i am trying some hive partitions but i am getting the following errors. I need to drop specific rows from a Hive table, which is partitioned. Hive Alter Table - Learn Hive in simple and easy steps from basic to advanced concepts with clear examples including Introduction, Architecture, Installation, Data Types, Create Database, DROP TABLE [IF EXISTS] table_name [PURGE]; If you don't use purge the table goes to a Trash directory, from there the table can be recovered after drop it. ALTER TABLE Table DROP IF EXISTS PARTITION (source_key = 'heaven' , date >= '2020-05-01' , date < '2020-11-30' ); DROP TABLE statement always drops partitions metadata for both MANAGED and EXTERNAL tables because partitions can not exist without table. cc @aakulov The schema and partition spec will be replaced if changed. The fully qualified name of the field to be added to an existing column. Alter Table/Partition Compact Each month the data is added incrementally to the table so the next partition added would be '2020-05'. You will have to run 2 separate queries (calling the hive Scenario: Trying to add new columns to an already partitioned Hive table. recover partitions: MSCK [REPAIR] TABLE tablename; The equivalent command on Amazon Elastic MapReduce (EMR)'s version of Hive is: ALTER TABLE tablename RECOVER PARTITIONS; This will add Hive partitions The EXCHANGE PARTITION command will move a partition from a source table to target table and alter each table's metadata. If we want to change the name of an existing table, we can rename that table by using the following signature: - So, I figured out the problem: When Spark creates partitions it creates these using user permissions, so in my case for the user dude and the group hdfs. Share. (CDH 5. For example, let‘s say we have a massive table Let's suppose I have two hive tables, table_1 and table_2. ALTER TABLE SET command is used for setting the SERDE or SERDE properties in Hive tables. etc sequence. I used this and it worked fine. Without CASCADE, if you want to change old partitions to include the new columns, you'll need to DROP the old partitions first and then fill them, INSERT OVERWRITE without the DROP won't work, because the metadata won't update to the new default metadata. It’s simple to run queries on slices of data when you use partition. If the table is cached, ALTER TABLE SET command is used for setting the SERDE or SERDE properties in Hive tables. truncate table my_table; // Deletes all data, but keeps partitions in metastore alter table my_table drop partition(p_col > 0) // does not work from spark Below command to add the partition to the table already created earlier. If we want to change the name of an existing table, we can rename that table by using the following signature: - ALTER TABLE table_name [PARTITION partition_spec] CHANGE [COLUMN] col_old_name col_new_name column_type [COMMENT col_comment] [FIRST|AFTER column_name] [CASCADE|RESTRICT]; As this is an external table, you can drop the table and re-create again with specific changes. I use: ALTER TABLE table_2 ADD PARTITION (col=val) LOCATION [table_1_location] Now, table_2 will have the Simply using a partition_options clause with ALTER TABLE on a partitioned table repartitions the table according to the partitioning scheme defined by the partition_options. ALTER TABLE TABLE1 ADD COLUMNS Try ALTER TABLE DROP PARTITION (Code='2021-06-25',date='Adjustment'). there is a double-column called _c1 and such columns are created by the hive itself when we moving data from one table to another. I am able to delete specific partition using ALTER statement as follow : The command should work. So you must ALTER each and every existing partition with this kind You can use drop command to delete meta data and actual data from HDFS. Here is the scenario : Have 'n' partitions on existing external table 't' Dropped table 't' Recreated table 't' // Note : same table but with excluding some column; How to recover the 'n' partitions that existed for table 't' in step #1 ? I can manually alter table to add 'n' partition by writing some After creating a partitioned table, Hive does not update metadata about corresponding objects or directories on the file system that you add or drop. This would have to rewrite the complete dataset since partitions are mapped to folders in HDFS/S3/FileSystem. I have Hive table partitioned based on date yyyy-mm-dd. Alter hive table add or drop column. Managing partitions is not supported for Delta Lake tables. ALTER TABLE table_identifier DROP [IF EXISTS] partition_spec [PURGE] Parameters. Stack Overflow. alter table test drop if exists partition (data_updated='NO'); Finally Worked for Me and did some work around. This partition delete is done every month to retain only the last 24 months data. changes in One way to dynamically pass date to the hiveql statement is by using hive variables, let assume we have hive script named alter. Add a new partition in hive external table and update the existing partition to column of the table to non-partition column Load 7 more related questions Show fewer related questions Finally Worked for Me and did some work around. Modified 8 years, 9 months ago. hive> ALTER TABLE test. disallow. Trash/Current directory if Trash is configured You can not change the partition column in hive infact Hive does not support alterting of partitioning columns. you need to add partition. . ALTER TABLE ExternalExample ADD PARTITION . type. 1) Create Temp table with same columns. To create a partitioned table in Hive, you can use the PARTITIONED BY clause along with the CREATE TABLE statement. To avoid modifying the table's schema and partitioning, use INSERT OVERWRITE instead of REPLACE TABLE. but somehow when data is ingested into the hive table something went wrong and partition is showing _hive_default_partition_ or in my understanding it is null partition. Using partition, it is easy to query a portion of the data. It provides SQL like commands to alter the table. CREATE TABLE ramesh. The ALTER TABLE DROP PARTITION statement does not provide a single syntax for dropping all partitions at once or support filtering criteria to specify a range of partitions to drop. As most of my tables have daily partition, this would significantly increase the number of partitions over time. When I am writing my drop partitions like ALTER TABLE TABLE1 DROP IF EXISTS PARTITION (TBL_DATE >= 20160910), then it I am trying to drop hive partitions in hive table using following command in hive-0. As others have noted CASCADE will change the metadata for all partitions. Clearly this is going to fail. Options. Hive expects a static date value (e. Table Level: If you don't use purge, How to recover partitions in easy fashion. I have to drop and recreate the table for the data to show up. The MSCK REPAIR TABLE command was designed to manually add partitions that are added to or removed from the file system, but are not present in the Hive metastore. Learn how to use ALTER TABLE command to change or delete Hive partitions that store data in HDFS subdirectories. Query is : ALTER TABLE maineventslog ADD COLUMNS (test_column int) I have resolved the issue, since my table contains plenty of partitions its taking time, with less number of partitions i am able to add column with 'cascade' . Community; Training; Partners; Support; Cloudera Community. From this table I want to drop the column Dob. However, this keyword should be used with caution since if a table or partition is accidentally deleted, it cannot be retrieved. When purge keyword is added it will skip the . The partition metadata in the Hive metastore becomes stale after corresponding objects/directories are added or deleted. final. Alter external table as internal table -- by changing the TBL properties as external =false. Hive table can have one or multiple partition keys . Dropping Add a new partition in hive external table and update the existing partition to column of the table to non-partition column Load 7 more related questions Show fewer related questions Multiple partitions can be dropped with the following syntax: alter table historical_data drop partition (year = 1996 and month between 1 and 6); Please see our Dropping Columns # The following SQL drops two columns c1 and c2 from table my_table. ALTER TABLE PARTITION. Solution: One of the workaround can be copying/moving the data in a temporary location,dropping the partition, adding back the data and then adding back the partition. ) alter table int_test drop if exists partition So there is a shortcut to drop columns from a hive table. DROP PARTITION. i have been to some other post regarding the same issue and i I found other simple solution for this issue, Simply find faulty partition from partition list by using command. To identify a certain partition, each table in the hive can have one or more partition keys. I wanna write a shell script that will drop partitions for multiple tables in hive that have partitions greater than 10 days, How to write a shell script that will alter tables drop partitions in hive for more than 10 days for multiple tables(by importing a hql file) Ask Question Asked 2 years, 7 months ago. 4,937 1 1 gold badge 21 21 silver badges 39 39 bronze badges. In Hive, we can perform modifications in the existing table like changing the table name, column name, comments, and table properties. I needed to add a new column to the table, so i used ALTER to add the column like below. Applies to: Databricks SQL Databricks Runtime Alters the schema or properties of a table. How can the ALTER command be framed to drop the partitions with values older than 24 months. Hive - Alter Table. If table is MANAGED, then DROP TABLE will delete table and partitions metadata and data in table location as well, all the table location including What is the way to automatically update the metadata of Hive partitioned tables? What to be done if a lot of partitioned data were deleted from HDFS (without the execution of alter table drop partition commad execution). 0 and later, IGNORE PROTECTION not available 2. This clause always begins with PARTITION BY, and follows the same syntax and other rules as apply to the partition_options clause for CREATE TABLE (for more detailed information, see Section Now I have some partitions already added e. Hive ALTER TABLE command is used to update or drop a partition from a Hive Metastore and HDFS location (managed table). my_table SET LOCATION '/some_loc'; followed by. Create EXTERNAL table using updated DDL with types changed and with the same LOCATION. 2, 1. Anyway, that means hive DROP PARTITION. The easiest way that I see is drop your partitions base on conditions like this. I need to drop part Dropping Columns # The following SQL drops two columns c1 and c2 from table my_table. Correct. Use CASCADE option to drop all the objects in the database too. 2nd approach (MSCK repair): MSCK REPAIR will not work if you change table location because partitions are mounted to old locations outside table location. partition=true and hive. Basically I want the column - col2 to be removed from the partitioned column list, but I should not lose the data in col2. I want to drop the partitions that are older than 24 months. You need to synchronize the metastore and the Drop table (only metadata will be removed). my_table; I see the partitions, but the are referencing the old location. i have been to some other post regarding the same issue and i I've created a hive table with two partition columns say col 1 and col2, now for some analytical purpose I wish to delete the col2 partition. Unless FIRST or AFTER name are specified the column or field will be appended at the end. Solved: Hi All, Below is the hive table partitions(three level partitions) I have. I have a hive table, I want to add column into it. In Impala, this is primarily a logical operation that updates the table metadata in the metastore The schema and partition spec will be replaced if changed. ALTER TABLE table_name CHANGE old_col_name new_col_name new_data_type Here you can change I had a similar issue, but my partition key was in timestamp format and I accidentally created a partition with a string value. ALTER TABLE ADD|REPLACE COLUMNS with CASCADE command changes the columns of a table's metadata, and cascades the same change to all the partition metadata. 7, Hive 1. dynamic. i am trying to delete a null/HIVE_DEFAULT_PARTITION in from hive external table and also from HDFS directory but i couldn't delete it . ALTER TABLE employee DROP PARTITION (entry_date>'2021-03-14',entry_date<'2021-12-16'); Dropping all the partitions. Hive DDL Database Commands. You can add new column to the table. You can use ALTER TABLE with DROP PARTITION option to drop a partition for a table. Drop Partitions 删除分区 ALTER TABLE table_name DROP [IF EXISTS] PARTITION partition_spec [, PARTITION partition_spec,] [IGNORE PROTECTION] [PURGE];-- (Note: PURGE available in Hive 1. 6,322 How can i delete all data and drop all partitions from a Hive table, using Spark 2. , 'YYYY-MM-DD') in the DROP PARTITION statement, not a function call. Create again the table with the new schema (Partition value as a string). The data is actually moved to the We have created partitioned tables, inserted data into them. Altering a table while keeping Iceberg and Hive schemas in sync; Altering the partition schema (updating columns) Altering the partition schema by specifying partition transforms; Truncating a table / partition, dropping a partition. Please note I dont want to drop the table and recreate it. Why do I need to drop and add the partition again after refreshing the Hive metastore? Also, how does MSCK ADD AND DROP PARTITION ADD PARTITION. Refer to Differences between Hive External and Internal (Managed) Tables to understand the differences Is there any way to skip Trash while dropping a partition using the command below from a Managed Table in Hive? ALTER TABLE &lt;table&gt; DROP PARITION (&lt;partition_name&gt;) Similar to what we @Reddy The commands below work: Hive does not accept subquery in that DDL clause, but this works: ALTER TABLE myTable DROP PARTITION (date < 'date1') , PARTITION (date >'date2'); It needs literals for 'date1' and 'date2'. You need to synchronize the metastore and the Make sure no other process is writing to the table. This guide will help you to rank 1 on Google for the keyword 'alter ALTER TABLE table_name DROP partition_spec, partition_spec, 用户可以用 ALTER TABLE DROP PARTITION 来删除分区。分区的元数据和数据将被一并删除。例： ALTER TABLE This chapter explains how to alter the attributes of a table such as changing its table name, changing column names, adding columns, and deleting or replacing columns. In Hive, tables are used to store structured data in a tabular format. drop partition first (alter table drop partition) then mkdir then show partitions. patch. Alter Table Drop partitions 201804 / 201611 / 201705 Add newly merged partitions back to Original table ( having new updates ) I need to automate this scripts - Can you please suggest how to put above logic in hive QL or spark - Speacifically Identify partitions and drop them from original table. Then I tried: ALTER TABLE tablename RENAME COLUMN old_name TO new_name Syntax: RENAME COLUMN is only supported Purge in Apache Hive aids in the permanent deletion of data. Oracle Database processes a DROP TABLE statement for a partitioned table in the same way that it processes You cannot drop column directly from a table using command ALTER TABLE table_name drop col_name; The only way to drop column is using replace command. MSCK REPAIR is a resource-intensive query and Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about You cannot add a column with a default value in Hive. I tried: ALTER TABLE tablename CHANGE COLUMN old_name new_name Syntax: Renaming column is not supported in Hive-style ALTER COLUMN, please run RENAME COLUMN instead. Example: I have created partition table with cl as partition column stringtype. Syntax: ALTER TABLE table_name DROP PARTITION partition_specifaction; Example: ALTER TABLE CitiesList hive> ALTER TABLE sales drop if exists partition (year = 2020, quarter = 1), partition (year = 2020, quarter = 2); Here is how we dynamically pick partitions to drop. Below command to add the partition to the table already created earlier. Delete target partitions. I have a hive main table and data ingestion is happening to that table everyday. how to alter hive table partition Labels: Labels: Apache Hadoop; Apache Hive; Hortonworks Data Platform (HDP) bshah1. Add a comment | It's simple usually to change/modify the exesting table use this syntax in Hive. Improve this answer. ALTER TABLE This post will go through how to remove a table partition. Prerequisites . Refresh hive metadata to read the partitions again. This clause always copy the data in that partition to some other location in hdfs. 1:10000> ALTER TABLE zipcodes DROP IF EXISTS PARTITION Solution: alter table myTable drop partition (unix_timestamp('date1','yyyy-MM-dd')>unix_timestamp(myDate,‌ 'yyyy-MM-dd'),unix_t‌ imestamp('date2','yy‌ yy-MM To drop partitions with a Range filter, use below syntax. c. I have a table with partitions like below : TABLE logs PARTITION(year = 2019, month = 06, day = 18) partitions 'year', 'month' and 'day' are in string format. In hive catalog, you need to ensure disable hive. It is a way of dividing a table into related parts based on the values of partitioned columns such as date, city, and department. Here is the scenario : Have 'n' partitions on existing external table 't' Dropped table 't' Recreated table 't' // Note : same table but with excluding some column; How to recover the 'n' partitions that existed for table 't' in step #1 ? I can manually alter table to add 'n' partition by writing some I would like to delete multiple partitions in Hive table. Sort By Name; Sort By Date; Ascending; Descending; HIVE-2908. I tried adding column separately, which worked. We can modify multiple numbers of properties associated with the table schema in the Hive. ALTER TABLE table DROP PARTITION(yr_no=__HIVE_DEFAULT_PARTITION__); ALTER TABLE table DROP PARTITION(yr_no<1); First command complained since the column is int and 2nd complained about the syntax < Is there a simple way to drop it on yr_no=HIVE_DEFAULT_PARTITION or Hive table partition is a way to split a large table into smaller logical tables based on one or more partition keys. drop the old table; rename new table to old table. Parameters. Here is the example of creating partitions at multiple levels. ALTER TABLE is used to add, rename, drop partitions; SHOW PARTITIONS is used to show the partitions of the table; MSCK REPAIR is used to synch Hive Metastore with the HDFS data. Search. The cache will be lazily filled when the next time the table or the dependents are accessed. Your best bet at this point will be to recreate the table without the partitioning. You can have multiple tables sit on top of the same data without issues, it doesn't mean a table definition change in one affects the other. The RECOVER 1st approach will work. If the table is cached, the command clears cached data of the table and You can just drop it if you want it*/ ALTER TABLE original_table RENAME TO old_table; /*rename partitioned_table to original_table*/ ALTER TABLE partitioned_table When I am trying to rename all partition columns in an existing table for date range of one year which are partitioned - this is what I am getting. I think that's what you should do. The RECOVER ALTER TABLE table_name DROP [IF EXISTS] PARTITION partition_spec PURGE; But for External tables have a two-step process to alter table drop partition + removing file. trash folder gets full your Simply using a partition_options clause with ALTER TABLE on a partitioned table repartitions the table according to the partitioning scheme defined by the partition_options. I have a spark job (Scala) which writes time-series data onto Hadoop over which there is an external table in Hive. The new table Recovering Table Partitions . ADD AND DROP PARTITION ADD PARTITION. Hive's ALTER TABLE DROP PARTITION statement doesn't directly accept DATE_ADD or similar functions inside the partition specification. This table is a MANAGED - 160024 In this post let us learn how to drop partition in hive using examples . column_identifier. What is the way to syncup the Hive metatdata? hive; partitioning; Share. When I do show partitions db. You can add new partition or drop the existing partition using Hive alter command. External and internal tables. Lets I need to drop specific rows from a Hive table, which is partitioned. In my case, I used ALTER table table_name partition (date_flag Drop 3 partitions from original table. ctnto ljlb mxgy dwlio rhstb xine jxii ctm srhud sbmc