[IMPALA-9818] Add fetch size as option to impala shell

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: Impala 4.0.0
• Component/s: Clients
• Epic Color: ghx-label-10
• Assignee: Sahil Takiar
• Reporter: Sahil Takiar
• Created: 02/Jun/20 16:59
• Updated: 15/May/23 12:19
• Resolved: 10/Jun/20 17:52

Description

The impala shell should have an option to control the fetch size (e.g. the number of rows fetched at a time). Currently the value is hard-coded to 1024. Other clients (e.g. JDBC) have similar options (e.g. Statement#setFetchSize).

When result spooling is enabled, setting a higher fetch size can improve performance for clients with a high RTT to/from the Impala coordinator.

Issue Links

• is related to: IMPALA-12142 Default fetch_size of 10240 is suboptimal
• relates to: IMPALA-8656 Support for eagerly fetching and spooling all query result rows