[TINKERPOP-1312] .count().is(0) is not properly optimized

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.2.0-incubating, 3.1.2-incubating
• Fix Version/s: 3.1.3, 3.2.1
• Component/s: process
• Assignee: Daniel Kuppitz
• Reporter: Daniel Kuppitz
• Created: 25/May/16 17:12
• Updated: 23/Feb/17 14:34
• Resolved: 27/May/16 11:49

Description

bla.count().is(0) gets optimized by RangeByIsCountStrategy, which replaces it with bla.limit(1).count().is(0). That's good, but we can do even better by replacing it with __.not(bla), which is a simple .hasNext() instead of a RangeStep followed by a ReducingBarrierStep (count()).

Question is: should we do the replacement in RangeByIsCountStrategy? The strategy will recognize the pattern, no matter if we use it for the replacement or not; it's just that the strategy name is then no longer in line with the the actual replacement (for this particular .count().is(0) case) as it won't inject a RangeStep.

Issue Links

• relates to: TINKERPOP-1638 count() is optimized away in where()
• links to: GitHub Pull Request #320