Hive Partitions. All Rights Reserved. 09:53 AM, But this is not a suitable solution for production environment, Find answers, ask questions, and share your expertise. With the below alter script, we provide the exact partitions we would like to delete. Let’s discuss Apache Hive partiti… First two partitions are incorrect partitions created due to a bug in my insert hive script. One possible approach mentioned in HIVE-1079 is to infer view partitions automatically based on the partitions of the underlying tables. What is the difference between Hive internal tables and external tables? Then check mysql again, it is gone finally. The Hive tutorial explains about the Hive partitions. Natasha is a Content Manager at SpringPeople. La sintaxis siguiente se utiliza para eliminar una partición: ALTER TABLE table_name DROP [IF EXISTS] PARTITION partition_spec, PARTITION partition_spec,...; La siguiente consulta se utiliza para eliminar una partición: In addition, we can use the Alter table add partition command to add the new partitions for a table. ALTER TABLE table_identifier DROP [IF EXISTS] partition_spec [PURGE] Parameters. Drop or Delete Hive Partition You can use ALTER TABLE with DROP PARTITION option to drop a partition for a table. See HIVE-874 and HIVE-17824 for more Our requirement is to drop multiple partitions in hive. Re: Hive : Drop Partitions : How to drop Date partitions containing non-date values? In the last few articles, we have covered most of the details of Partitioning in Hive. The only difference is when you drop a partition on internal table the data gets dropped as well, but when you drop a partition on external table the data remains as is. DROP TABLE IF EXISTS specific_columns; OK Time taken: 0.008 seconds CREATE TABLE specific_columns AS SELECT driverId, eventTime, eventType FROM truck_events_subset; WARNING: Hive-on-MR is deprecated in Hive 2 and may not be available in the future versions. Drop multiple partitions in Hive Suppose we are having a hive partition table. Here is how we dynamically pick partitions to drop. 2. Below is the hive table partitions(three level partitions) I have. This can be achieved as below. 1. Created Most of it is the raw data but a significant amount is the final product of many data enrichment processes. 2. 10:53 AM, Created The SYNC PARTITIONS option is equivalent to calling both ADD and DROP PARTITIONS. Syntax. Given below are the advantages expressed. Without partitioning, any query on the table in Hive will read the entire data in the table. Let us create a table to manage “Wallet expenses”, which any digital wallet channel may have to track customers’ spend behavior, having the following columns: In order to track monthly expenses, we want to create a partitioned table with columns month and spender. DROP IF EXISTS PARTITION(month_partitionkey = ‘__HIVE_DEFAULT_PARTITION__’); Another amazing day. ‎03-16-2017 If a property was already set, overrides the old value with the new one. ‎03-21-2017 Create table. alter table historical_data drop partition (year < 1995, last_name like 'A%'); This technique can also be used to change the file format of groups of partitions, as part of an ETL pipeline that periodically consolidates and rewrites the underlying data files in a different file format: Hive Insert into Partition Table. You can learn more about Hive External Table here. The corrected date is under hdfs://user/svc_account/fixed_date/2020/2. Syntax Drop multiple partitions With the below alter script, we provide the exact partitions we would like to delete. DROP PARTITION. I tried multiple ALTER table DROP partitions, but nothing worked for me. Partitioning allows Hive to run queries on a specific set of data in the table based on the value of partition column used in the query. Later some days, i found this and i want to drop these two partitions somehow. Alter external table as internal table -- by changing the TBL properties as external =false. However, depending on on the partition column type, you might not be able to drop those partitions due to restrictions in the Hive code. The following query is used to drop a partition: hive > ALTER TABLE employee DROP [IF EXISTS] > PARTITION (Class=’6’); Author Bio. Below script drops all partitions from sales table with year greater than 2019. Column - source_system is of STRING data type. DROP VIEW IF EXISTS English_class; DROP TABLE command cannot be used to drop a view if the EXISTS clause works similarly for tables. Here is the alter command to update the partition of the table sales. It will not work if you use the same value displayed above to drop it, even if Hive says OK. hive> alter table… Hadoop Notes My notes on Hadoop, Cloud, and other BigData technologies hive> ALTER TABLE employee PARTITION (year=’1203’) > RENAME TO PARTITION (Yoj=’1203’); Eliminar una partición. Please help me with the options if any to create external partitions and during a reload we are supposed to drop those partitions as well. Partitioning is also one of the core strategies to improve query performance in a hive. Hive : Drop Partitions : How to drop Date partitions containing non-date values? Partitioning is the optimization technique in Hive which improves the performance significantly. How to skip the first line or header when reading a file in Hive? Partition keys are basic elements for determining how the data is stored in the table. Let’s say you had an issue with the way the data was loaded into a partition and now you have found a way to fix the data and fixed it. This column got inserted with '${hiveconf:reporting_date}' value instead of '2016-12-09'. For an external table, If you are trying to drop a partition and as-well would like to delete the data. Collectively we have seen a wide range of problems, implemented some innovative and complex (or simple, depending on how you look at it) big data solutions on cluster as big as 2000 nodes. ALTER TABLE some_table DROP IF EXISTS PARTITION(year = 2012); This command will remove the data and metadata for this partition. Column - break_type is of STRING data type. SHOW PARTITIONS table_name [PARTITION(partition_spec)] [WHERE where_condition] [ORDER BY column_list] [LIMIT rows]; Conclusion. hive> alter table testpart drop partition (partcol=3); Dropped the partition partcol=3 OK Time taken: 0.751 seconds 5. For example, if we need only 5 columns from a table of 50 columns, we can create a view. HIVE-2922 PartitionSpec should have a API for getting partition filter string instead of using toString() Open HIVE-8804 Hive: Extend DROP PARTITION syntax to use all comparators with date partition Created Let’s see a few variations of drop partition. So today we learnt how to show partitions in Hive Table. ALTER TABLE some_table DROP IF EXISTS PARTITION (year = 2012); This command will remove the data and metadata for this partition. 2 ALTER Table Drop Partition in Hive ALTER TABLE ADD PARTITION in Hive Alter table statement is used to change the table structure or properties of an existing table in Hive. We know that Hive will create a partition with value “__HIVE_DEFAULT_PARTITION__” when running in dynamic partition mode and the value for the partition key is “null” value. If we have a large table then queries may take long time to … CREATE TABLE test (col1 string) PARTITIONED BY (p1 int) ROW FORMAT DELIMITED FIELDS TERMINATED BY '\001' STORED AS TEXTFILE; INSERT OVERWRITE TABLE test PARTITION (p1) SELECT code, IF(salary > 60000, 100, null) as p1 FROM default.sample_07; hive> SHOW PARTITIONS test; OK p1=100 p1=__HIVE_DEFAULT_PARTITION__ Time taken: 0.124 seconds, Fetched: 2 row(s) hive> ALTER TABLE test DROP partition … Also the use of where limit order by clause in Partitions which is introduced from Hive 4.0.0. Advantages of Views. Partitioning is one of the important topics in the Hive. Instead of loading each partition with single SQL statement as shown above, which will result in writing lot of SQL statements for huge no of partitions, Hive supports dynamic partitioning with which we can add any number of partitions with single SQL execution. As mentioned earlier, inserting data into a partitioned Hive table is quite different compared to relational databases. However, with the help of CLUSTERED BY clause and optional SORTED BY clause in CREATE TABLE statement we can create bucketed tables. My personal opinion about the decision to save so many final-product tables in the HDFS is that it’s a bad pr… Partitioning in Hive 32 . ‎08-21-2017 Dynamic Partitioning in Hive. Example: CREATE TABLE IF NOT EXISTS hql.customer(cust_id INT, name STRING, created_date DATE) COMMENT … Drops the partition of the table. Let’s say you had an issue with the way the data was loaded into a partition and now you have found a way to fix the data and fixed it. You must specify the partition column in your insert command. Column - reporting_date is of DATE data type. This is fairly easy to do for use case #1, but potentially very difficult for use cases #2 and #3. Moreover, we can create a bucketed_user table with above-given requirement with the help of the below HiveQL.CREATE TABLE bucketed_user( firstname VARCHAR(64), lastname VARCHAR(64), address STRING, city VARCHAR(64),state VARCHAR(64), post STRI… Can anyone please help me? It is a common use case in your production jobs or Hive scripts to update or drop a Hive partition from your table. partition_spec.