[IMPALA-2176] Inconsistency in the handling of SET commands by the Impala shell

• Type: Bug
• Status: Resolved
• Priority: Minor
• Resolution: Cannot Reproduce
• Affects Version/s: Impala 2.3.0
• Component/s: Clients
• Labels: shell
• Target Version: Product Backlog
• Assignee: Unassigned
• Reporter: Andre Araujo
• Created: 04/Aug/15 23:48
• Updated: 11/Jun/18 19:30
• Resolved: 11/Jun/18 19:30

Description

The Impala shell handle SET commands in two different ways:

• Locally, if the line starts with the keyword SET (e.g. "SET EXPLAIN_LEVEL=3")
• As a query, if the lines starts with a comment (e.g. "-- dummy comment\nSET EXPLAIN_LEVEL=3")

In the first case above the shell keeps the state of the set options locally and passes that to the Beeswax service as a configuration object. In the second case, the whole statement (comments included) are sent to the Impala frontend as a query.

The inconsistency in handling SET statements, causes the Impala shell local configuration to go out-of-sync with the Impala frontend's, as shown below:

[poti:21000] > set explain_level=3;
EXPLAIN_LEVEL set to 3
[poti:21000] > -- this one executes as a query
             > set explain_level=2;
Query: --
set explain_level=2

Fetched 0 row(s) in 0.27s
[poti:21000] > set;
Query options (defaults shown in []):
...
	EXPLAIN_LEVEL: 3
...
[poti:21000] > -- again, this executes as a query
             > set;
Query: --
set
+---------------------------------+-------+
| option                          | value |
+---------------------------------+-------+
...
| EXPLAIN_LEVEL                   | 2     |
...
+---------------------------------+-------+
Fetched 31 row(s) in 0.01s
[poti:21000] >