[CASSANDRA-14512] DESCRIBE behavior is broken for Virtual Keyspaces/Tables (CQLSH)

• Type: Bug
• Status: Resolved
• Priority: Normal
• Resolution: Duplicate
• Fix Version/s: 4.0-alpha4, 4.0
• Component/s: Legacy/CQL, Legacy/Observability
• Labels: virtual-tables
• Severity: Normal
• Assignee: Benjamin Lerer
• Reporter: Benjamin Lerer

Authors

Benjamin Lerer

• Created: 12/Jun/18 09:06
• Updated: 15/May/20 08:54
• Resolved: 09/Apr/20 09:01

Description

The DESCRIBE command in CQLSH does not work properly for virtual keyspaces/tables.

1. For the DESCRIBE KEYSPACES the virtual keyspaces are correctly added to the list but for DESCRIBE TABLES only the non virtual tables are displayed.
2. DESCRIBE system_views return the error: 'system_views' not found in keyspaces. Similar error for DESCRIBE system_virtual_schema.
3. DESCRIBE KEYSPACE system_views or DESCRIBE KEYSPACE system_virtual_schema return the error: 'NoneType' object has no attribute 'export_for_schema'

The DESCRIBE TABLE command works fine but the output might be confusing as it is a CREATE statement.

cqlsh> DESCRIBE TABLE system_virtual_schema.tables;

CREATE TABLE system_virtual_schema.tables (
    comment text,
    keyspace_name text,
    table_name text,
    PRIMARY KEY (keyspace_name, table_name)
) WITH CLUSTERING ORDER BY (table_name ASC)
    AND compaction = {'class': 'None'}
    AND compression = {};

I would be in favor or replacing the CREATE TABLE by a VIRTUAL TABLE. cnlwsu, iamaleksey What do you think?

Issue Links

• duplicates: CASSANDRA-14872 Update to version of python driver and update cqlsh to use driver metadata for virtual tables
• links to: Blocked by PYTHON-992