[OAK-937] Query engine index selection tweaks: shortcut and hint

• Type: Improvement
• Status: Closed
• Priority: Critical
• Resolution: Fixed
• Fix Version/s: 1.7.6, 1.8.0
• Component/s: query
• Labels: performance
• Epic Link: Query performance improvements
• Assignee: Thomas Mueller
• Reporter: Alex Deparvu
• Created: 31/Jul/13 16:11
• Updated: 31/Jul/22 10:36
• Resolved: 18/Aug/17 09:39

Description

This issue covers 2 different changes related to the way the QueryEngine selects a query index:

Firstly there could be a way to end the index selection process early via a known constant value: if an index returns a known value token (like -1000) then the query engine would effectively stop iterating through the existing index impls and use that index directly.

Secondly it would be nice to be able to specify a desired index (if one is known to perform better) thus skipping the existing selection mechanism (cost calculation and comparison). This could be done via certain query hints [0].

[0] http://en.wikipedia.org/wiki/Hint_(SQL)

Issue Links

• is related to: OAK-4888 Warn or fail queries above a configurable cost value