[ASTERIXDB-2286] Parallel Sort Optimization

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Done
• Affects Version/s: 0.9.4
• Fix Version/s: 0.9.4.2
• Component/s: COMP - Compiler, FUN - Functions, HYR - Hyracks
• Labels: triaged
• Assignee: Ali Alsuliman
• Reporter: Ali Alsuliman
• Created: 15/Feb/18 06:29
• Updated: 12/Apr/19 03:42
• Resolved: 12/Apr/19 03:42

Description

The current plan for queries with ORDER BY clauses consists of two phases; sorting the data locally in each partition and then sort-merging the data in one single partition. Even though the local sort happens in parallel, this effort is wasted by the fact that the merge is happening at one partition. It is desired to remove the merge step and do a true parallel sort where data is range-partitioned across the cluster.