[IMPALA-4418] Extra blank lines in query result

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: Impala 2.5.0
• Fix Version/s: Impala 2.10.0
• Component/s: Clients
• Labels: newbie
• Assignee: Vincent Tran
• Reporter: Matyas Orhidi
• Created: 02/Nov/16 15:47
• Updated: 24/Aug/17 16:58
• Resolved: 16/Jun/17 11:46

Description

Adding a leading comment line before the 'use <dbname>' command causing unwanted extra blank lines in the query result. Below are the steps to reproduce the problem:

[root@morhidi-572-sec-1 ~]# myimpala -V -f sample.sql --print_header --output_delimiter='|' -B -o result.csv
Connected to morhidi-572-sec-2.gce.cloudera.com:21000
Server version: impalad version 2.5.0-cdh5.7.2 RELEASE (build 1140f8289dc0d2b1517bcf70454bb4575eb8cc70)
Query: -- comment
use default
Fetched 0 row(s) in 0.01s
Query: select * from sample_07 limit 10
Fetched 10 row(s) in 0.14s

The two extra blank lines can be seen before the query header:

[root@morhidi-572-sec-1 ~]# cat result.csv 


code|description|total_emp|salary
00-0000|All Occupations|134354250|40690
11-0000|Management occupations|6003930|96150
11-1011|Chief executives|299160|151370
11-1021|General and operations managers|1655410|103780
11-1031|Legislators|61110|33880
11-2011|Advertising and promotions managers|36300|91100
11-2021|Marketing managers|165240|113400
11-2022|Sales managers|322170|106790
11-2031|Public relations managers|47210|97170
11-3011|Administrative services managers|239360|76370

The problem is caused by the leading – comment in the script, and can be seen only when 'use <dbname>' is issued before the query:

[root@morhidi-572-sec-1 ~]# cat sample.sql 
-- comment
use default;
select * from sample_07 limit 10;
[root@morhidi-572-sec-1 ~]#