[IMPALA-5641] mem-estimate should never be less than mem-reservation

• Type: Bug
• Status: Resolved
• Priority: Critical
• Resolution: Fixed
• Fix Version/s: Impala 2.10.0
• Component/s: Frontend
• Labels: resource-management
• Target Version: Impala 2.10.0
• Epic Color: ghx-label-9
• Assignee: Tim Armstrong
• Reporter: Tim Armstrong
• Created: 10/Jul/17 21:52
• Updated: 22/Aug/17 15:39
• Resolved: 22/Aug/17 15:39

Description

Once we switch over to the new buffer pool, the mem-reservation is a hard floor for the actual memory consumption. The planner's resource profiles should reflect this, instead of reporting things like this:

02:HASH JOIN [LEFT OUTER JOIN]
|  hash predicates: 2 + a.id = b.id - 2
|  fk/pk conjuncts: assumed fk/pk
|  other join predicates: a.int_col <= b.bigint_col + 97, a.int_col >= 0 + b.bigint_col
|  other predicates: CAST(b.double_col AS DECIMAL(3,2)) > 11.1
|  mem-estimate=15.68KB mem-reservation=136.00MB