Does Hive Support Update?

Does Hive support transaction?

Transactions in Hive are introduced in Hive 0.13, but they only partially fulfill the ACID properties like atomicity, consistency, durability, at the partition level.

Transactions are provided at the row-level in Hive 0.14.

The different row-level transactions available in Hive 0.14 are as follows: Insert..

Can we update data in Hadoop?

You need updates in Hadoop. Performing data updates in Hadoop is hard. … HDFS files are immutable, meaning you cannot edit a file after it has been written. Hive very recently added, and Pig does not (yet) provide an update command, much less a merge statement.

How can you tell if a table is internal or external in hive?

For external tables Hive assumes that it does not manage the data. Managed or external tables can be identified using the DESCRIBE FORMATTED table_name command, which will display either MANAGED_TABLE or EXTERNAL_TABLE depending on table type.

When would you choose to create an external Hive table?

Use EXTERNAL tables when:The data is also used outside of Hive. … Data needs to remain in the underlying location even after a DROP TABLE. … You want to use a custom location such as ASV.Hive should not own data and control settings, dirs, etc., you have another program or process that will do those things.More items…•

How do I get the difference between two tables in hive?

Hive query to compare 2 tables Number of distinct records can be found using the following query: select count(*) from (select distinct * from table1) if DC1 and DC2 are not equal, the tables are not identical. 3: Now get the number of records obtained by performing a union on the 2 tables.

Is hive a NoSQL database?

Hive and HBase are two different Hadoop based technologies . Hive is a SQL-like engine that runs MapReduce jobs, and HBase is a NoSQL key/value database on Hadoop. But just as Google can be used for search and Facebook for social networking, Hive can be used for analytical queries while HBase for real-time querying.

In which mode HiveServer2 accepts just real thrift calls in hive?

In remote mode HiveServer2 only accepts valid Thrift calls – even in HTTP mode, the message body contains Thrift payloads.

How do I edit a file in HDFS?

Get the original file from HDFS to the local filesystem, modify it and then put it back on HDFS.hdfs dfs -get /user/hduser/myfile.txt.vi myfile.txt #or use any other tool and modify it.hdfs dfs -put -f myfile.txt /user/hduser/myfile.txt.

Why hive is not a database?

No, we cannot call Apache Hive a relational database, as it is a data warehouse which is built on top of Apache Hadoop for providing data summarization, query and, analysis. … Hive is read-based and therefore not support transaction processing that typically involves a high percentage of write operations.

Where are external tables stored in hive?

External tables are stored outside the warehouse directory. They can access data stored in sources such as remote HDFS locations or Azure Storage Volumes. Whenever we drop the external table, then only the metadata associated with the table will get deleted, the table data remains untouched by Hive.

What is difference between external table and managed table in hive?

Managed tables are Hive owned tables where the entire lifecycle of the tables’ data are managed and controlled by Hive. External tables are tables where Hive has loose coupling with the data. … If a Managed table or partition is dropped, the data and metadata associated with that table or partition are deleted.

Is Hadoop ACID compliant?

Hadoop itself has no concept of transactions (or even records, for that matter), so it clearly isn’t an ACID-compliant system. Thinking more specifically about data storage and processing projects in the entire Hadoop ecosystem, none of them is fully ACID-compliant, either.

Can we truncate external table in hive?

If we want to remove particular row from Hive meta store Table we use DELETE but if we want to delete all the rows from HIVE table we can use TRUNCATE. if you had created a TABLE with EXTERNAL keyword then you can NOT remove all the rows because all data resides outside of Hive Meta store. …

What is the use of Hive in Hadoop?

Apache Hive is a data warehouse software project built on top of Apache Hadoop for providing data query and analysis. Hive gives an SQL-like interface to query data stored in various databases and file systems that integrate with Hadoop.

How do I check my hive Metastore version?

If you are using beeline to connect to hive, then ! dbinfo will give all the underlying database details and in the output getDatabaseProductVersion will have the hive database version. We can also get the version by looking at the version of the hive-metastore jar file.

Does hive require Hadoop?

1 Answer. Hive provided JDBC driver to query hive like JDBC, however if you are planning to run Hive queries on production system, you need Hadoop infrastructure to be available. Hive queries eventually converts into map-reduce jobs and HDFS is used as data storage for Hive tables.

Can we update hive external table?

You can not have latest data in the query output . Other is external table in which hive will not copy its data to internal warehouse . So whenever you fire query on table then it retrieves data from the file. SO you can even have the latest data in the query output.

What is the latest version of Hive?

The latest stable release for hive came in 2019 August that is in use. There are various versions which was released for HIVE, making it more stable and function enhancement….Top 7 Versions of HiveVersion 0.9. Hive version 0.9. … Version 0.10. … Version 0.11. … Version 0.12. … Version 0.13. … Version 1.0. … Version 1.2.

Is hive schema on read?

Hive enforces schema during read time.

How do you perform CRUD in hive?

You can set these configuration in hive-site. xml (after setting restart Hive ) for ever or via terminal….HIVE CRUD Operation How to Check Hive Version? HIVE CREATE TABLE. HIVE INSERT INTO TABLE. HIVE SELECT. HIVE UPDATE. HIVE DELETE FROM TABLE.

How do I run a compaction in hive?

Use the accompanying hive query to perform compaction….Approach to enable compaction on Non-Transactional tablesFind out the list of all partitions which holds more than 5 files, this can be done by using the hive virtual column ‘input__file__name’.Set the reducer size to define approximate file size.More items…•