The describe statement in Impala is used to give the description of the table. The result of this statement contains the information about a table such as the column names and their data types.
Following is the syntax of the Impala describe statement.
Describe table_name;
For example, assume we have a table named customer in Impala, with the following data −
ID NAME AGE ADDRESS SALARY --- --------- ----- ----------- ----------- 1 Ramesh 32 Ahmedabad 20000 2 Khilan 25 Delhi 15000 3 Hardik 27 Bhopal 40000 4 Chaitali 25 Mumbai 35000 5 kaushik 23 Kota 30000 6 Komal 22 Mp 32000
You can get the description of the customer table using the describe statement as shown below −
[quickstart.cloudera:21000] > describe customer;
On executing the above query, Impala fetches the metadata of the specified table and displays it as shown below.
Query: describe customer +---------+--------+---------+ | name | type | comment | +---------+--------+---------+ | id | int | | | name | string | | | age | int | | | address | string | | | salary | bigint | | +---------+--------+---------+ Fetched 5 row(s) in 0.51s
Open Impala Query editor and type the describe statement in it and click on the execute button as shown in the following screenshot.
After executing the query, if you scroll down and select the Results tab, you can see the metadata of the table as shown below.