Hive insert into partitioned table

1. How do I load data into a dynamic partitioned table in Hive?
2. How will you insert data from non-partitioned table to partitioned table in Hive?
3. What does insert overwrite with partition do in Hive?
4. How do I add multiple partitions in Hive?
5. Does SQL insert overwrite?
6. How dynamic partitions are added to a Hive managed table?
7. What is Hive dynamic partitioning?
8. What is the disadvantage of using too many partitions in Hive tables?
9. How do I copy a partitioned table in hive?
10. How can I see partitions in hive?
11. What does MSCK repair table do?
12. Does Hive support insert update and delete?
13. Does Hive support insert?
14. Can a Hive table have multiple partitions?
15. How do I choose a partition column in Hive?
16. Can we use two columns in partition by?

How do I load data into a dynamic partitioned table in Hive?

For dynamic partitioning, you have to use INSERT ... SELECT query (Hive insert). Inserting data into Hive table having DP, is a two step process. Create staging table in staging database in hive and load data into that table from external source such as RDBMS, document database or local files using Hive load.

How will you insert data from non-partitioned table to partitioned table in Hive?

You can use this command to create that: hive> INSERT INTO TABLE Y PARTITION(state) SELECT * from X; Here you should ensure that the partition column is the last column of the non-partitioned table.

What does insert overwrite with partition do in Hive?

INSERT OVERWRITE is used to replace any existing data in the table or partition and insert with the new rows. When working with the partition you can also specify to overwrite only when the partition exists using the IF NOT EXISTS option.

How do I add multiple partitions in Hive?

hive>alter table alt_part add partition(yop=2013,mop=9) location '/user/revathi-prac/partitions/dec21/yop=2013/mop=9';

Does SQL insert overwrite?

The INSERT OVERWRITE statement overwrites the existing data in the table using the new values. The inserted rows can be specified by value expressions or result from a query.

How dynamic partitions are added to a Hive managed table?

In dynamic partitioning of hive table, the data is inserted into the respective partition dynamically without you having explicitly create the partitions on that table. When specifying the dynamic partition, keep in mind that you should not use high cardinality column as that will create lot of sub-directories.

What is Hive dynamic partitioning?

Dynamic partitioning is the strategic approach to load the data from the non-partitioned table where the single insert to the partition table is called a dynamic partition.

What is the disadvantage of using too many partitions in Hive tables?

Limitations: Having large number of partitions create number of files/ directories in HDFS, which creates overhead for NameNode as it maintains metadata. It may optimize certain queries based on where clause, but may cause slow response for queries based on grouping clause.

How do I copy a partitioned table in hive?

CREATE new_table AS SELECT * FROM original_table WHERE (conditions); However, because the original table is so big, I have to iterate through this query via the partitions. My current solution is to write a shell script that iterates through all partitions and runs a separate query for each partition.

How can I see partitions in hive?

The general syntax for showing partitions is as follows: SHOW PARTITIONS [db_name.] table_name [PARTITION(partition_spec)];

What does MSCK repair table do?

MSCK REPAIR TABLE recovers all the partitions in the directory of a table and updates the Hive metastore. When creating a table using PARTITIONED BY clause, partitions are generated and registered in the Hive metastore. ... User needs to run MSCK REPAIR TABLE to register the partitions.

Does Hive support insert update and delete?

Though Hive latest versions support ACID transactions like Update and Delete records, Hive doesn't enable them by default hence you can't perform Delete or Update operations. ... Transaction tables can be created, update, and read from only the ACID Transaction Manager session.

Does Hive support insert?

INSERT ... VALUES, UPDATE, DELETE, and MERGE SQL statements are supported in Apache Hive 0.14 and later. The INSERT ... VALUES statement enable users to write data to Apache Hive from values provided in SQL statements.

Can a Hive table have multiple partitions?

In Hive, partitioning is supported for both managed and external tables in the table definition as seen below. As you can see, multi-column partition is supported (REGION/COUNTRY).

How do I choose a partition column in Hive?

The ideal choice is to have state as partitioning column as partitioning creates distinct folders based on distinct values. Hence number of folders = number of states and so the metadata information storage to Namenode would be less.

Can we use two columns in partition by?

No. Partition by clause allows multiple columns.