impala-reviews mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Zach Amsden (Code Review)" <>
Subject [Impala-ASF-CR] IMPALA-5003: Constant propagation in scan nodes
Date Thu, 06 Apr 2017 00:17:55 GMT
Zach Amsden has posted comments on this change.

Change subject: IMPALA-5003: Constant propagation in scan nodes

Patch Set 16:

File testdata/workloads/functional-planner/queries/PlannerTest/constant-propagation.test:

Line 159:  select count(*) from
> There's still a question as to whether we should impose a limit on the size
I'll probably just re-use the same rule.

Line 245: (coalesce(NULL, T.int_col) + random() * T.tinyint_col = 100 OR
> This is the current intended behavior. See the bottom of hdfs.test planner 
It is fixable.  I think this is because the resulting Expr ends up with no SlotRefs, and as
a result conjunct.isBoundBySlotIds(partitionSlots_) returns true, which is questionable. 
Changing that would have deep consequences, but we can always build something to collect all
the SlotRefs from an Expr and validate they are a non-empty subset of partitionSlots_

Line 289: where l_partkey < l_suppkey and c.c_nationkey = 10 and o_orderkey = o_shippriority
and l_suppkey = 10 and o_shippriority = c_nationkey
> long line

Line 335: 00:SCAN HDFS [functional.alltypes]
> Why not an EmptySetNode?
bool_col = null is stripped from conjunct evaluation.  bool_col IS null is not.  I am guessing
because 10 = null => null and 10 IS NULL => false.

Is this behavior incorrect?  It certainly is suspect, but there are some comments about how
conjunct evaluation treats null conditions specially and I wasn't sure which was the correct
behavior here.

To view, visit
To unsubscribe, visit

Gerrit-MessageType: comment
Gerrit-Change-Id: I79750a8edb945effee2a519fa3b8192b77042cb4
Gerrit-PatchSet: 16
Gerrit-Project: Impala-ASF
Gerrit-Branch: master
Gerrit-Owner: Zach Amsden <>
Gerrit-Reviewer: Alex Behm <>
Gerrit-Reviewer: Dan Hecht <>
Gerrit-Reviewer: Marcel Kornacker <>
Gerrit-Reviewer: Zach Amsden <>
Gerrit-HasComments: Yes

View raw message