Suppose we are having a hive partition table. This table is partitioned by the year of joining. Our requirement is to drop multiple partitions in hive. Here, 1 record belongs to 1 partition as we will store data partitioned by the year of joining. In actual, there will be many records for each partition. If you already have a partitioned table, then skip this step else read this post for creating a table and loading data into it. If you see sample data, we are having 10 partitions of the year from to In case, you want to add multiple partitions in the table, then mention all the partitions in the query like given below:.

Here, we are going to drop partitionand only. Here, I have mentioned all css blur div specific partitions separated by a comma in the query. It will drop all mentioned partitions in a single query. Here, We want to drop all partition above the value of That means we have to drop the partition from the value to In this post, we have seen how we can add multiple partitions as well as drop multiple partitions from the hive table. We can drop multiple specific partitions as well as any range kind of partition.

You must be logged in to post a comment. Drop multiple partitions in Hive In: Hive. Share Tweet LinkedIn. Subscribe to our newsletter. Leave a Reply Cancel reply You must be logged in to post a comment. Load CSV file in hive Requirement If you have comma separated file and you want to create a table in the hive on top of it Split one column into multiple columns in hive Requirement Suppose, you have one table in hive with one column and you want to split this column in This file contains some empty tag.

Partitioning in Hive Requirement Suppose there is a source data, which is required to store in the hive partitioned tableBy using our site, you acknowledge that you have read and understand our Cookie PolicyPrivacy Policyand our Terms of Service. The dark mode beta is finally here. Change your preferences any time. Stack Overflow for Teams is a private, secure spot for you and your coworkers to find and share information.

I have a Hive ver 0. I want to know if there exists a way in Hive by which I can drop partitions for a range of dates say from 'date1' to 'date2'. I have tried the following SQL type queries, but they don't seem to be syntactically correct:. I don't think there is any valid solution to date. I implemented a workaround for this issue using some shell scripts, like for instance:. Obviously the loops should be able to generate the range you want to drop, which might be nontrivial.

In the worst case you will need to use several such shell scripts in order to drop the desired range of dates. Further, please note that in my case the partitions had four keys year, month, day, hour. Learn more. Asked 4 years, 5 months ago. Active 1 year, 10 months ago. Viewed 17k times. Rajeev Atmakuri Rajeev Atmakuri 1 1 gold badge 9 9 silver badges 20 20 bronze badges. Active Oldest Votes. Will make this as the answer. I tried this syntax it worked. Kharthigeyan Kharthigeyan 1 1 silver badge 8 8 bronze badges.

I think this will drop everything on the table? Larger than OR smaller than HakkiBuyukcengiz HakkiBuyukcengiz 3 3 silver badges 15 15 bronze badges.

Hive - Partitioning

What is here date1, date2 and myDate. Say you want to delete between and ? Sign up or log in Sign up using Google. Sign up using Facebook. Sign up using Email and Password. Post as a guest Name. Email Required, but never shown. The Overflow Blog.Most of the keywords are reserved through HIVE in order to reduce the ambiguity in grammar version 1. There are two ways if the user still would like to use those reserved keywords as identifiers: 1 use quoted identifiers, 2 set hive.

It only changes the default parent-directory where new tables will be added for this database. This behaviour is analogous to how changing a table-directory does not move existing partitions to a different location.

To revert to the default database, use the keyword " default " instead of a database name. An error is thrown if a table or view with the same name already exists. See Alter Table below for more information about table comments, table properties, and SerDe properties. By default Hive creates managed tables, where files, metadata and statistics are managed by internal Hive processes.

For details on the differences between managed and external table see Managed vs. External Tables. Hive supports built-in and custom-developed file formats. See CompressedStorage for details on compressed table storage. The following are some of the formats built-in to Hive:. You can create tables with a custom SerDe or using a native SerDe. For more information on SerDes see:.

Hive: Extend ALTER TABLE DROP PARTITION syntax to use all comparators

You must specify a list of columns for tables that use a native SerDe. Refer to the Types part of the User Guide for the allowable column types. A list of columns for tables that use a custom SerDe may be specified but Hive will query the SerDe to determine the actual list of columns for this table.

To use the SerDe, specify the fully qualified class name org. A table can have one or more partition columns and a separate data directory is created for each distinct value combination in the partition columns. This can improve performance on certain kinds of queries. If, when creating a partitioned table, you get this error: "FAILED: Error in semantic analysis: Column repeated in partitioning columns," it means you are trying to include the partitioned column in the data of the table itself.

You probably really do have the column defined. However, the partition you create makes a pseudocolumn on which you can query, so you must rename your table column to something else that users should not query on! Now you want to partition on date.By using our site, you acknowledge that you have read and understand our Cookie PolicyPrivacy Policyand our Terms of Service. The dark mode beta is finally here. Change your preferences any time. Stack Overflow for Teams is a private, secure spot for you and your coworkers to find and share information.

SQL Alter Statement - Add Column, Drop Column, Change Column Datatype

I have a Hive ver 0. I want to know if there exists a way in Hive by which I can drop partitions for a range of dates say from 'date1' to 'date2'.

hive alter table drop column partition

I have tried the following SQL type queries, but they don't seem to be syntactically correct:. I don't think there is any valid solution to date. I implemented a workaround for this issue using some shell scripts, like for instance:. Obviously the loops should be able to generate the range you want to drop, which might be nontrivial. In the worst case you will need to use several such shell scripts in order to drop the desired range of dates. Further, please note that in my case the partitions had four keys year, month, day, hour.

Learn more. Asked 4 years, 5 months ago. Active 1 year, 10 months ago. Viewed 17k times. Rajeev Atmakuri Rajeev Atmakuri 1 1 gold badge 9 9 silver badges 20 20 bronze badges.

Scheduled queries

Active Oldest Votes. Will make this as the answer. I tried this syntax it worked.

hive alter table drop column partition

Kharthigeyan Kharthigeyan 1 1 silver badge 8 8 bronze badges. I think this will drop everything on the table? Larger than OR smaller than HakkiBuyukcengiz HakkiBuyukcengiz 3 3 silver badges 15 15 bronze badges.In Impala, this is primarily a logical operation that updates the table metadata in the metastore database that Impala shares with Hive.

When you do an ALTER TABLE operation, you typically need to perform corresponding physical filesystem operations, such as rewriting the data files to include extra fields, or converting them to a different file format. In CDH 5. For example, you can use Impala to update metadata for a staging table in a non-Parquet file format where the data is populated by Hive.

The exception is renaming a table; for an external table, the underlying data directory is not renamed or moved. For example, you might drop a group of partitions corresponding to a particular date range after the data "ages out" :. For tables with multiple partition keys columns, you can specify multiple conditions separated by commas, and the operation only applies to the partitions that match all the conditions similar to using an AND clause :.

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:. Prior to CDH 5. When Impala processes a cached data block, where the cache replication factor is greater than 1, Impala randomly selects a host that has a cached copy of that data block.

This optimization avoids excessive CPU usage on a single host when the same cached data block is processed multiple times. Cloudera recommends specifying a value greater than or equal to the HDFS block replication factor. For internal tables, this operation physically renames the directory within HDFS that contains the data files; the original directory name no longer exists.

By qualifying the table names with database names, you can use this technique to move an internal table and its associated data directory from one database to another. For example:. To change the owner of a table:. The table owner is originally set to the user who creates the table.

To change the physical location where Impala looks for data files associated with a table or partition:. The path you specify is the full HDFS path where the data files reside, or will be created. Impala does not create any additional subdirectory named after the table. Impala does not move any data files to this new location or change any data files that might already exist in that directory. Specify all the same partitioning columns for the table, with a constant value for each, to precisely identify the single partition affected by the statement:.I have a table in my source database having columns monthid intmonthshort string.

I copy the data of the table daily using nifi and store in hdfs. Now the schema in the source table change to : monthid intmonthlong string ,monthshort string. One option is to delete existing external table and create new table that includes new column. Since this is Hive metadata operation, your data files wont be touched.

Downside is that you will have to execute alter table command to redefine partitions on new table. Support Questions. Find answers, ask questions, and share your expertise.

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hive alter table drop column partition

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hive alter table drop column partition

Coming from Hortonworks? Activate your account here.Am new to hive, We had requirement to add columns to existing hive table. I did that with the help of below command. But in hive documentation, we have alter command to add columns at partition level.

I tried below commands. Have tried below commands as well, but still neither i am able to query newly added column nor able to insert the data. Support Questions. Find answers, ask questions, and share your expertise. Turn on suggestions. Auto-suggest helps you quickly narrow down your search results by suggesting possible matches as you type. Showing results for. Search instead for. Did you mean:. Alert: Welcome to the Unified Cloudera Community. Former HCC members be sure to read and learn how to activate your account here.

All forum topics Previous Next. Adding Column at partition level in hive. Labels: Apache Hive. What does above alter command do when we add columns at partition level? Hive Version - Hive 2. Reply 1, Views. Tags 3. Tags: Data Processing. Already a User? Sign In.