[CALCITE-832] General optimization rules for Limit

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Duplicate
• Assignee: Julian Hyde
• Reporter: Wei Xue
• Created: 07/Aug/15 18:22
• Updated: 07/Aug/15 19:28
• Resolved: 07/Aug/15 19:28

Description

1. LimitUnionRule:
Rule that applies to a Limit on top of a Union. The original Limit won't go away after applying this rule, but additional Limit nodes will be created on top of each child of Union, so that these children produce less rows and Limit can be further optimized for children Rels.

2. LimitJoinRule:
Rule that applies to a Limit on top of an OUTER Join. The original Limit won't go away after applying this rule, but additional Limit node(s) will be created on top of the outer-side child (or children if it's a FULL OUTER Join). This will have impact on the cost of modified child node(s) as well as that of the join node itself (among different join algorithms).

Issue Links

• duplicates: CALCITE-831 Rules to push down limits