Cloudera Impala Query UI

The Cloudera Impala Query UI application enables you to perform queries on Apache Hadoop data stored in HDFS or HBase using Cloudera Impala. For information about Cloudera Impala, see Installing and Using Cloudera Impala. You can create, run, and manage queries, and download the results in a Microsoft Office Excel worksheet file or a comma-separated values file.

Cloudera Impala Query UI Installation and Configuration

The Cloudera Impala Query UI application is one of the applications installed as part of Hue. For information about installing and configuring Hue, see the Hue Installation manual..

The Cloudera Impala Query UI assumes an existing Cloudera Impala installation. The Hue installation instructions include the configuration necessary for Impala. You can view the current configuration from the Settings tab.

Starting Cloudera Impala Query UI

Click the Cloudera Impala Query UI icon (image) in the navigation bar at the top of the Hue browser page.

Managing Databases, Tables, and Partitions

You can create databases, tables, partitions, and load data by executing Hive data manipulation statements in the Beeswax application.

You can also use the Metastore Manager application to manage the databases, tables, and partitions and load data.

When you change the metastore using one of these applications, you must click the Refresh button under METASTORE CATALOG in the pane to the left of the Query Editor to make the metastore update visible to the Cloudera Impala server.

Installing Example Queries and Tables

image Note: You must be a superuser to perform this task.

  1. Click image. The Quick Start Wizard opens.
  2. Click Step 2: Examples.
  3. Click Cloudera Impala Query UI.

Query Editor

The Query Editor view lets you create queries in the Cloudera Impala Query Language, which is based on the Hive Standard Query Language (HiveQL) and described in the Cloudera Impala Language Reference topic in Installing and Using Cloudera Impala.

You can name and save your queries to use later.

When you submit a query, you can either wait for the query to complete, or return later to find the queries in the History view.

In the box to the left of the Query field, you can select a database, override the default Cloudera Impala settings, enable users to enter parameters at run-time. See Advanced Query Settings for details on using these settings.

Creating Queries

  1. In the Query Editor window, type a query or multiple queries separated by a semicolon ";". To be presented with a drop-down of autocomplete options, type CTRL+spacebar when entering a query.
  2. To save your query and advanced settings to use again later, click Save As, enter a name and description, and then click OK. To save changes to an existing query, click Save.

Loading Queries into the Query Editor

  1. Do one of the following:

  2. Click a query name. The query is loaded into the Query Editor.

Running Queries

image Note: To run a query, you must be logged in to Hue as a user that also has a Unix user account on the remote server.

  1. To execute a portion of the query, highlight one or more query statements.
  2. Click Execute. The Query Results window appears with the results of your query.
  3. If there are multiple statements in the query, click Next in the Multi-statement query pane to execute the remaining statements.

Advanced Query Settings

The pane to the left of the Query Editor lets you specify the following options:

DATABASEThe database containing the table definitions.
SETTINGSOverride the Cloudera Impala default settings. To configure a new setting:
  1. Click Add.
  2. For Key, enter a Hive or Hadoop configuration variable name.
  3. For Value, enter the value you want to use for the variable. For example, to override the directory where structured Hive query logs are created, you would enter hive.querylog.location for Key, and a path for Value.
To view the default settings, click the Settings tab at the top of the page.
PARAMETERIZATIONIndicate that a dialog box should display to enter parameter values when a query containing the string $parametername is executed. Enabled by default.
METASTORE CATALOGRefresh metadata. It is best to refresh metadata after making changes to databases such as adding or dropping a table.

Viewing Query History

You can view the history of queries that you have run previously. Results for these queries are available for one week or until Hue is restarted.

  1. Click History. A list of your saved and unsaved queries displays in the Query History window.
  2. To display the queries for all users, click Show everyone's queries. To display your queries only, click Show my queries.
  3. To display the automatically generated actions performed on a user's behalf, click Show auto actions. To display user queries again, click Show user queries.

Viewing, Editing, Copying, and Deleting Saved Queries

You can view a list of saved queries of all users by clicking My Queries and then selecting either Recent Saved Queries or Recent Run Queries tab to display the respective queries or clicking Saved Queries. You can copy any query, but you can edit, delete, and view the history of only your own queries.

Edit

  1. Click Saved Queries. The Queries window displays.
  2. Check the checkbox next to the query and click Edit. The query displays in the Query Editor window.
  3. Change the query and then click Save. You can also click Save As, enter a new name, and click OK to save a copy of the query.

Copy

  1. Click Saved Queries. The Queries window displays.
  2. Check the checkbox next to the query and click Copy. The query displays in the Query Editor window.
  3. Change the query as necessary and then click Save. You can also click Save As, enter a new name, and click OK to save a copy of the query.

Copy in Query History

  1. Click History. The Query History window displays.
  2. To display the queries for all users, click Show everyone's queries. The queries for all users display in the History window.
  3. Click the query you want to copy. A copy of the query displays in the Query Editor window.
  4. Change the query, if necessary, and then click Save As, enter a new name, and click OK to save the query.

Delete

  1. Click Saved Queries. The Queries window displays.
  2. Check the checkbox next to the query and click Delete.
  3. Click Yes to confirm the deletion.