[IMPALA-10894] Pushing down predicates in reading "original files" of ACID tables

• Type: Improvement
• Status: Resolved
• Priority: Critical
• Resolution: Fixed
• Fix Version/s: Impala 4.1.0
• Epic Link: ORC Performance
• Epic Color: ghx-label-9
• Assignee: Quanlong Huang
• Reporter: Quanlong Huang
• Created: 29/Aug/21 11:10
• Updated: 28/Sep/21 14:03
• Resolved: 28/Sep/21 14:03

Description

“Original files” don't store special ACID columns. We generate the row id by using the row index of the file. The orc reader doesn't provide interfaces for retrieving the row index of a row in the file. When predicates are pushed down into the orc reader, the returned batch will skip some rows. So we can't calculate the actual row index in file using its index in the batch.

Currently we skip pushing down predicates in reading such files.