Miscellaneous

How Hive read data from HDFS?

How Hive read data from HDFS?

​Moving Data from HDFS to Hive Using an External Table

  1. Move .CSV data into HDFS:
  2. Create an external table.
  3. Create the ORC table.
  4. Insert the data from the external table to the Hive ORC table.

How do I import data into Hive?

Loading data into Hive Table

  1. Using Insert Command. We can load data into a table using Insert command in two ways. One Using Values command and other is using queries.
  2. Using Load. You can load data into a hive table using Load statement in two ways.
  3. Using HDFS command.

How do I import a CSV file from HDFS to Hive?

Hive LOAD CSV File from HDFS

  1. Create a data file (for our example, I am creating a file with comma-separated columns)
  2. Now use the Hive LOAD command to load the file into the table.

Does Hive work with HDFS?

Apache Hive is an open source data warehouse software for reading, writing and managing large data set files that are stored directly in either the Apache Hadoop Distributed File System (HDFS) or other data storage systems such as Apache HBase.

How do I import a text file into Hive?

You can load the text file into a textfile Hive table and then insert the data from this table into your sequencefile. Now load into the sequence table from the text table: insert into table test_sq select * from test_t; Can also do load/insert with overwrite to replace all.

How do I import CSV data into Hive table?

For the purpose of a practical example, this tutorial will show you how to import data from a CSV file into an external table.

  1. Step 1: Prepare the Data File. Create a CSV file titled ‘countries.csv’: sudo nano countries.csv.
  2. Step 2: Import the File to HDFS. Create an HDFS directory.
  3. Step 3: Create an External Table.

How do I import a CSV file into Hive table?

There is another way of enabling this,

  1. use hadoop hdfs -copyFromLocal to copy the . csv data file from your local computer to somewhere in HDFS, say ‘/path/filename’
  2. enter Hive console, run the following script to load from the file to make it as a Hive table.

How do I view table contents in Hive?

There are three ways to describe a table in Hive.

  1. To see table primary info of Hive table, use describe table_name; command.
  2. To see more detailed information about the table, use describe extended table_name; command.
  3. To see code in a clean manner use describe formatted table_name; command to see all information.

How do I display table data in Hive?

Accessing RCFile-Format Hive Tables

  1. Start the hive command line and create a Hive table stored in RCFile format: $ HADOOP_USER_NAME=hdfs hive.
  2. Insert the data from the sales_info table into sales_info_rcfile :
  3. Query the sales_info_rcfile Hive table to verify that the data was loaded correctly:
  4. Query the external table:

Which Hive command will load data from an HDFS file directory to the table?

LOAD DATA INPATH
hive> LOAD DATA INPATH ‘/user/myname/kv2. txt’ OVERWRITE INTO TABLE invites PARTITION (ds=’2008-08-15′); The above command will load data from an HDFS file/directory to the table.

How do I import csv data into Hive table?

Which tool is required to import data from any database to Hive?

You can test the Apache Sqoop import command and then execute the command to import relational database tables into Hive. You enter the Sqoop import command on the command line of your Hive cluster to import data from a data source to Hive. You can test the import statement before actually executing it.