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From "Tim Armstrong (Code Review)" <ger...@cloudera.org>
Subject [Impala-ASF-CR] IMPALA-4302,IMPALA-2379: constant expr arg fixes
Date Mon, 07 Nov 2016 17:46:32 GMT
Hello Internal Jenkins, Dan Hecht,

I'd like you to reexamine a change.  Please visit

    http://gerrit.cloudera.org:8080/4838

to look at the new patch set (#7).

Change subject: IMPALA-4302,IMPALA-2379: constant expr arg fixes
......................................................................

IMPALA-4302,IMPALA-2379: constant expr arg fixes

This patch fixes two issues around handling of constant expr args.
The patches are combined because they touch some of the same code
and depend on some of the same memory management cleanup.

First, it fixes IMPALA-2379, where constant expr args were not visible
to UDAFs. The issue is that the input exprs need to be opened before
calling the UDAF Init() function.

Second, it avoids overhead from repeated evaluation of constant
arguments for ScalarFnCall expressions on both the codegen'd and
interpreted paths. A common example is an IN predicate with a
long list of constant values.

The interpreted path was inefficient because it always evaluated all
children expressions. Instead in this patch constant args are
evaluated once and cached. The memory management of the AnyVal*
objects was somewhat nebulous - adjusted it so that they're allocated
from ExprContext::mem_pool_, which has the correct lifetime.

The codegen'd path was inefficient only with varargs - with fixed
arguments the LLVM optimiser is able to infer after inlining that
the expressions are constant and remove all evaluation. However,
for varargs it stores the vararg values into a heap-allocated buffer.
The LLVM optimiser is unable to remove these stores because they
have a side-effect that is visible to code outside the function.

The codegen'd path is improved by evaluating varargs into an automatic
buffer that can be optimised out. We also make a small related change
to bake the string constants into the codegen'd code.

Testing:
Ran exhaustive build.

Added regression test for IMPALA-2379 and MemPool test for aligned
allocation. Added a test for in predicates with constant strings.

Perf:
Added a targeted query that demonstrates the improvement. Also manually
validated the non-codegend perf. Also ran TPC-H and targeted perf
queries locally - didn't see any significant changes.

+--------------------+-------------------------------+-----------------------+--------+-------------+------------+-----------+----------------+-------------+-------+
| Workload           | Query                         | File Format           | Avg(s) | Base
Avg(s) | Delta(Avg) | StdDev(%) | Base StdDev(%) | Num Clients | Iters |
+--------------------+-------------------------------+-----------------------+--------+-------------+------------+-----------+----------------+-------------+-------+
| TARGETED-PERF(_20) | primitive_filter_in_predicate | parquet / none / none | 1.19   | 9.82
       | I -87.85%  |   3.82%   |   0.71%        | 1           | 10    |
+--------------------+-------------------------------+-----------------------+--------+-------------+------------+-----------+----------------+-------------+-------+

(I) Improvement: TARGETED-PERF(_20) primitive_filter_in_predicate [parquet / none / none]
(9.82s -> 1.19s [-87.85%])
+--------------+------------+----------+----------+------------+-----------+----------+----------+------------+--------+--------+-----------+
| Operator     | % of Query | Avg      | Base Avg | Delta(Avg) | StdDev(%) | Max      | Base
Max | Delta(Max) | #Hosts | #Rows  | Est #Rows |
+--------------+------------+----------+----------+------------+-----------+----------+----------+------------+--------+--------+-----------+
| 01:AGGREGATE | 14.39%     | 155.88ms | 214.61ms | -27.37%    |   2.68%   | 163.38ms | 227.53ms
| -28.19%    | 1      | 1      | 1         |
| 00:SCAN HDFS | 85.60%     | 927.46ms | 9.43s    | -90.16%    |   4.49%   | 1.01s    | 9.50s
   | -89.42%    | 1      | 13.77K | 14.05K    |
+--------------+------------+----------+----------+------------+-----------+----------+----------+------------+--------+--------+-----------+

Change-Id: I45c3ed8c9d7a61e94a9b9d6c316e8a53d9ff6c24
---
M be/src/benchmarks/in-predicate-benchmark.cc
M be/src/codegen/gen_ir_descriptions.py
M be/src/codegen/llvm-codegen.cc
M be/src/codegen/llvm-codegen.h
M be/src/exec/partitioned-aggregation-node.cc
M be/src/exprs/agg-fn-evaluator.cc
M be/src/exprs/aggregate-functions-ir.cc
M be/src/exprs/anyval-util.cc
M be/src/exprs/anyval-util.h
M be/src/exprs/case-expr.cc
M be/src/exprs/expr-context.h
M be/src/exprs/expr.cc
M be/src/exprs/expr.h
M be/src/exprs/hive-udf-call.cc
M be/src/exprs/in-predicate.h
M be/src/exprs/literal.cc
M be/src/exprs/scalar-fn-call.cc
M be/src/exprs/scalar-fn-call.h
M be/src/exprs/utility-functions-ir.cc
M be/src/runtime/free-pool-test.cc
M be/src/runtime/free-pool.h
M be/src/runtime/mem-pool-test.cc
M be/src/runtime/mem-pool.cc
M be/src/runtime/mem-pool.h
M be/src/testutil/test-udas.cc
M be/src/udf/udf-internal.h
M be/src/udf/udf-test-harness.cc
M be/src/udf/udf.cc
M be/src/udf/udf.h
M be/src/util/bit-util.h
M testdata/workloads/functional-query/queries/QueryTest/exprs.test
M testdata/workloads/functional-query/queries/QueryTest/uda.test
A testdata/workloads/targeted-perf/queries/primitive_filter_in_predicate.test
M tests/query_test/test_udfs.py
34 files changed, 576 insertions(+), 358 deletions(-)


  git pull ssh://gerrit.cloudera.org:29418/Impala-ASF refs/changes/38/4838/7
-- 
To view, visit http://gerrit.cloudera.org:8080/4838
To unsubscribe, visit http://gerrit.cloudera.org:8080/settings

Gerrit-MessageType: newpatchset
Gerrit-Change-Id: I45c3ed8c9d7a61e94a9b9d6c316e8a53d9ff6c24
Gerrit-PatchSet: 7
Gerrit-Project: Impala-ASF
Gerrit-Branch: master
Gerrit-Owner: Tim Armstrong <tarmstrong@cloudera.com>
Gerrit-Reviewer: Dan Hecht <dhecht@cloudera.com>
Gerrit-Reviewer: Internal Jenkins
Gerrit-Reviewer: Michael Ho
Gerrit-Reviewer: Tim Armstrong <tarmstrong@cloudera.com>

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