[JENA-111] Improving TopN optimization in case of an intermediate OpModifier

• Type: Improvement
• Status: Closed
• Priority: Minor
• Resolution: Done
• Fix Version/s: Jena 2.11.0
• Component/s: ARQ
• Labels: arq optimization
• Assignee: Paolo Castagna
• Reporter: Sara Magliacane
• Created: 06/Sep/11 17:20
• Updated: 01/Feb/15 19:11
• Resolved: 01/Feb/15 19:11

Description

In the TopN optimization (Jena-89) it would be useful to handle also the case in which there are some other OpModifiers (I think they are the only category of Ops that can be in that position in the tree) between Slice and Order By, for example OpProject:

(slice _1
(project ?s ...
(order by <condition>

->
(project ?s ...
(top 1 <condition>

Issue Links

• is blocked by: JENA-114 Enabling slice(0,N)-project-order optimization cause "open iterator" warnings.
• is related to: JENA-89 Avoid a total sort for ORDER BY + LIMIT queries