hive show specific partitions
"PARTITIONS" stores the information of Hive table partitions. Today, we are going to learn about partitions in Hive. Hive Tutorial: What are Hive Partitions and How to create them. You can designate the HDFS directory that holds the data files for a specific partition. Use the following commands to show partitions in Hive: The following command will list all the partitions present in the Sales table: Copy Show partitions The following command will list a specific partition of the Sales table: Copy Show partitions Sales The following command will list a . To , Hive partitioning can be used for improving the performance of a very specific set of queries, as long as the partitions are aligned with the attributes used in the queries’ filters. Dropping Partitions. It is a way of dividing a table into related parts based on the values of partitioned columns such as date, city, and dep To show the partitions in a table and list them in a specific order, see the Listing Partitions for a Specific Table section on the Querying AWS Glue Data Catalog page. Hive Partitions is a way to organizes tables into partitions by dividing tables into different parts based on partition keys. Let’s discuss some benefits and limitations of Apache Hive Partitioning-a) Hive Partitioning Advantages. Hive Partitioning – Advantages and Disadvantages. "SDS" stores the information of storage location, input and output formats, SERDE etc. We looked at the basics of creating a database, creating tables, loading data, querying data in the table and viewing the schema structure of the tables. Partitioning in Hive distributes execution load horizontally. This is used to list a specific partition of a table. The mechanism that lets queries skip certain partitions during a query is known as partition pruning. A highly suggested safety measure is putting Hive into strict mode, which prohibits queries of partitioned tables without a WHERE clause that filters on partitions. How to do it… Use the following commands to show partitions in Hive: The following command will list all the partitions present in the Sales table: Show partitions Sales; The following command will list a specific partition of the Sales table: To view the contents of a partition, see the Query the Data section on the Partitioning Data page. MSCK REPAIR is a resource-intensive query and using it to add single partition is not recommended especially when you huge number of partitions. 7. In partition faster execution of queries with the low volume of data takes place. In addition, the new target table is created using a specific SerDe and a storage format independent of the source tables in the SELECT statement. Hive - Partitioning - Hive organizes tables into partitions. MSCK REPAIR is a useful command and it had saved a lot of time for me. Partition keys are basic elements for determining how the data is stored in the table. Drop partitions:-hive# alter table partition_table drop partition(dt>'0') purge; //it will drop all the partitions (or) you can drop specific partition by mentioning as dt='2017-10-30'(it will drop only 2017-10-30 partition) INFO : Dropped the partition dt=2017-10-30 INFO : Dropped the partition dt=2017-10-31 No rows affected (0.132 seconds) J. Configure Hive to allow partitions-----However, a query across all partitions could trigger an enormous MapReduce job if the table data and number of partitions are large. Both "TBLS" and "PARTITIONS" have a foreign key referencing to SDS(SD_ID). Hive metastore 0.13 on MySQL Root Cause: In Hive Metastore tables: "TBLS" stores the information of Hive tables. Hive Facts Conclusion. SHOW PARTITIONS: ... issue a REFRESH table_name statement so that Impala recognizes any partitions or new data added through Hive. Partition is helpful when the table has one or more Partition keys. In the previous posts we learned about Hive as a Data Warehouse on top of HDFS data. Solution: 1.