Known issues and limitations

This section lists known issues and limitations that you might run into while using the Data Warehouse service.

General Known Issues in Data Warehouse service

There are no known issues.

Data Analytics Studio (DAS) in Data Warehouse service

DWX-1287: Reports do not get updated for any new queries.
Problem: You may not see any data for a report for any new queries that you run. This can happen, especially, for the last one day's report.
Workaround: N/A
DWX-929: DAS UI displays the internal JDBC URL.
Problem: DAS displays the internal JDBC URL on its About page instead of the correct JDBC URL to use to connect to the data warehouse.
Workaround: To copy the correct JDBC URL to use to connect to the data warehouse, in the Data Warehouse service Overview page, go to Virtual Warehouse > , and then click Copy JDBC URL.
DWX-951: You cannot configure any users for DAS in Data Warehouse service.
Problem: Currently, you cannot configure non-administrative users in DAS. All users, by default, are administrative (admin) users.
Workaround: Presently, there is no workaround for this issue.
EAR-9981: DAS cannot parse certain characters in strings and comments.
Problem: DAS cannot parse semicolons (;) and double hyphens (--) in strings and comments. For example if you have a semicolon in a query such as the following, the query might fail:

SELECT * FROM properties WHERE prop_value = "name1;name2";
           
Queries with double hyphens (--) might also fail. For example:

SELECT * FROM test WHERE option = '--name';
             
Workaround: If a semicolon is present in a comment, then remove the semicolon before running the query or remove the comment entirely. For example:

SELECT * FROM test; -- SELECT * FROM test;
             
Should be changed to:

SELECT * FROM test; /* comment; comment */
             
In the same manner, remove any double-hyphens before running queries to avoid failure in DAS.
Older versions of Google Chrome browser might cause issues.
Problem: You might experience problems while using faceted search in older versions of the Google Chrome browser.
Workaround: Use the latest version (71.x or later) of Google Chrome.
BUG-94611: Visual Explain for the same query shows different graphs.
Problem: Visual Explain for the same query shows different graphs on the Compose page and the Query Details page.
Workaround: N/A

Database Catalog

There are no known issues.

Hive 3 in Data Warehouse service

Result caching:
This feature is limited to 10 GB.
Data caching:
This feature is limited to 200 GB per compute node, multiplied by the total number of compute nodes.
DWX-1703: Cloudera Data Warehouse environment deletion fails intermittently
Problem: Intermittently, when you delete a Cloudera Data Warehouse environment it causes the Amazon CloudFormation stack to fail with a SecurityGroup dependency violation.
Workaround: Perform the following steps:
  1. Manually delete the SecurityGroup and any associated stale elastic network interfaces (ENIs) by using the AWS Management Console.
  2. Re-delete the Cloudera Data Warehouse environment.
DWX-1952: Cloned Hive Virtual Warehouses do not have query executors or query coordinators
Problem: When you clone an existing Hive Virtual Warehouse, it is created with only HiveServer and Data Analytics Studio (DAS) application container groups (Kubernetes pods). This means that the cloned Virtual Warehouse cannot execute queries.
Workaround:

To manually add query executors and query coordinators to the cloned Hive Virtual Warehouse:

  1. Click the options menu on the cloned Virtual Warehouse, and then select Edit:



  2. In the Virtual Warehouse edit page, change a value, such as the AutoSuspend Timeout setting, and then click Apply:



    This causes the Data Warehouse service to create query executors and query coordinators so you can execute queries on the cloned Virtual Warehouse.

Impala in Data Warehouse service

Data caching:
This feature is limited to 200 GB per compute node, multiplied by the total number of compute nodes.
Default file format changed to Parquet.
In CDP 1.0, the default file format for Impala was changed from text to Parquet. When you create a table, the default format for that table data is now Parquet unless you specify the STORED AS clause. For more information see the What's New in Apache Impala: Default File Format Changed to Parquet.
Global INVALIDATE METADATA statement is not supported.
Global use of the INVALIDATE METADATA statement is not supported and if it is used in scripts, they will exit on error without providing a warning. To use INVALIDATE METADATA, you must specify a table. For example:
INVALIDATE METADATA <table_name>;
ORC table support is disabled by default
If you use an Impala Virtual Warehouse to query ORC tables, the queries might fail.
Sessions with Impala continue to run for 15 minutes after the connection is disconnected.
When a connection to Impala is disconnected, the session continues to run for 15 minutes in case so the user or client can reconnect to the same session again by presenting the session_token. After 15 minutes, the client must re-authenticate to Impala to establish a new connection.