[IMPALA-11444] Wrong results in reading wide rows from ORC

• Type: Bug
• Status: Resolved
• Priority: Blocker
• Resolution: Fixed
• Affects Version/s: Impala 3.4.0, Impala 3.4.1
• Fix Version/s: Impala 3.4.2
• Component/s: Backend
• Labels: correctness
• Epic Color: ghx-label-7
• Assignee: Quanlong Huang
• Reporter: Quanlong Huang
• Created: 19/Jul/22 03:41
• Updated: 05/Feb/24 07:52
• Resolved: 19/Jul/22 11:02

Description

The bug only exists in 3.4 branches where we have IMPALA-9228 and is missing IMPALA-9469.

When reading from a wide table with tuple size larger than 4096 bytes (4KB), the orc scanner produces wrong results. The issue can be reproduced using the attached CreateTable stmt and the ORC file.

$ bin/impala-shell.sh --quiet -f create-table-512cols.sql
$ bin/impala-shell.sh -B --quiet -q 'show table stats orc_tbl_512cols'
-1	0	0B	NOT CACHED	NOT CACHED	ORC	false	hdfs://localhost:20500/test-warehouse/orc_tbl_512cols
$ hdfs dfs -put widerow_512cols.orc hdfs://localhost:20500/test-warehouse/orc_tbl_512cols
$ bin/impala-shell.sh -q 'refresh orc_tbl_512cols'

Then run the following query:

$ bin/impala-shell.sh -B -q "select * from orc_tbl_512cols where col0 = '1'"

The result should be only one row with all values as '1'. However, we get one rwo with all values as '1024'.

Issue Links

• links to: Code Review