[IGNITE-4510] SQL: co-located query may calculate target partition in advance in some cases

• Type: Task
• Status: Closed
• Priority: Major
• Resolution: Duplicate
• Affects Version/s: 1.8
• Component/s: sql
• Labels: sql-performance
• Assignee: Unassigned
• Reporter: Vladimir Ozerov
• Created: 29/Dec/16 09:50
• Updated: 12/Feb/19 09:35
• Resolved: 12/Feb/19 09:35

Description

Consider the following SQL query with distributedJoins=false:

SELECT ... 
FROM Employee e
    INNER JOIN Department d on d.id = e.dept_id
WHERE e.dept_id = ?

If dept_id is affinity key, and this should be certainly so in case of non-colocated joins (otherwise query will return incorrect result), then we can do the following:
1) Determine partition for this affinity key.
2) Send query execution request to this partition only.

Same technique can be applied to WHERE e.dept_id IN (?, ...) case.

Issue Links

• contains: IGNITE-4523 Allow distributed SQL query execution over explicit set of partitions
• is blocked by: IGNITE-4509 SQL: query with condition on affinity columns and without joins and subqueries should go to affinity node only
• relates to: IGNITE-4517 Add ability to execute SQL queries on certain partition(s)