[IMPALA-5081] Expose IR optimization level via query option

• Type: Improvement
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: Impala 4.4.0
• Component/s: Backend
• Labels: codegen
• Target Version: Product Backlog
• Epic Color: ghx-label-7
• Assignee: Michael Smith
• Reporter: Michael Ho
• Created: 16/Mar/17 21:47
• Updated: 24/Oct/23 05:00
• Resolved: 23/Oct/23 21:18

Description

Certain queries may spend a lot of time in the IR optimization. Currently, there is a start-up option to disable optimization in LLVM. However, it may be of inconvenience to users to have to restart the entire Impala cluster to just use that option. This JIRA aims at exploring exposing a query option for users to choose the optimization level for a given query (e.g. we can have a level which just only have a dead code elimination pass or no optimization at all).

Issue Links

• is related to: IMPALA-12314 Revisit pre-compiled IR at O1
• is related to: IMPALA-2651 codegen overhead can be high