[Impala-ASF-CR] IMPALA-10445: Adjust NDV's scale with query option
Impala Public Jenkins has posted comments on this change. ( http://gerrit.cloudera.org:8080/17306 ) Change subject: IMPALA-10445: Adjust NDV's scale with query option .. Patch Set 17: Verified+1 -- To view, visit http://gerrit.cloudera.org:8080/17306 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-MessageType: comment Gerrit-Change-Id: I1669858a6e8252e167b464586e8d0b6cb0d0bd50 Gerrit-Change-Number: 17306 Gerrit-PatchSet: 17 Gerrit-Owner: fifteencai Gerrit-Reviewer: Aman Sinha Gerrit-Reviewer: Impala Public Jenkins Gerrit-Reviewer: Qifan Chen Gerrit-Reviewer: Quanlong Huang Gerrit-Reviewer: fifteencai Gerrit-Comment-Date: Wed, 21 Apr 2021 08:45:56 + Gerrit-HasComments: No
[Impala-ASF-CR] IMPALA-10445: Adjust NDV's scale with query option
Impala Public Jenkins has submitted this change and it was merged. ( http://gerrit.cloudera.org:8080/17306 ) Change subject: IMPALA-10445: Adjust NDV's scale with query option .. IMPALA-10445: Adjust NDV's scale with query option This is a new way to control NDV's scale. Since IMPALA-2658, we can trade memory for more accurate estimation by setting larger `scale` in SQL function NDV(, ). However the use of larger NDV scale requires the modification of SQL queries which may not be practical in certain applications: - Firstly, SQL writers are reluctant to lower that scale. They prone to fill up the scale, which will make the cluster unstable. Especially when there are `group by`s with high cardinalities. So it is wiser to let cluster admin other than sql writer choose appropriate scale. - Secondly, In some application scenarios, queries are stored in DBs. In a BI system, for example, rewriting thousands of SQLs is risky. In this commit, we introduced a new Query Option `DEFAULT_NDV_SCALE` with the following semantics: 1. The allowed value is in the range [1..10]; 2. Previously, the scale used in NDV() functions was fixed at 2. Now the scale is provided by the newly added query options. 3. It does not influence the NDV scale for SQL function NDV(, ) in which the NDV scale is provided by the 2nd argument . We also refactored method `Analyze` to make sure APPX_COUNT_DISTINCT can work with this query option. After this, cluster admins can substitute `count(distinct )` with `ndv(, scale)`. Implementation details: - The default value of DEFAULT_NDV_SCALE is 2, so we won't change the default ndv behavior. - We port `CountDistinctToNdv` transform logic from `SelectStmt.analyze()` to `ExprRewriter`, making it compatible with further rewrite rules. - The newly added rewrite rule `DefaultNdvScaleRule` is applied after `CountDistinctToNdvRule`. Usage: To set a default ndv scale: ``` SET DEFAULT_NDV_SCALE = 10; ``` To unset: ``` SET DEFAULT_NDV_SCALE = 2; ``` Here are test results of a typical workload (cardinality=40,090,650): ++ | Metric| Count Distinct |NDV2|NDV5|NDV10 | ++ | Memory(GB) | 3.83 |1.84|1.85| 1.89 | | Duration(s) | 182.89| 30.22|29.72 | 29.24 | | ErrorRate |0% |1.8%|1.17% | 0.06% | ++ Testing: 1) Added 3 unit test cases in `ExprRewriteRulesTest`. 2) Added 5 unit test cases in `ExprRewriterTest`. 3) Ran all front-end unit test, passed. 4) Added a new query-option test. Change-Id: I1669858a6e8252e167b464586e8d0b6cb0d0bd50 Reviewed-on: http://gerrit.cloudera.org:8080/17306 Reviewed-by: Impala Public Jenkins Tested-by: Impala Public Jenkins --- M be/src/service/query-options-test.cc M be/src/service/query-options.cc M be/src/service/query-options.h M common/thrift/ImpalaService.thrift M common/thrift/Query.thrift M fe/src/main/java/org/apache/impala/analysis/Analyzer.java M fe/src/main/java/org/apache/impala/analysis/SelectStmt.java A fe/src/main/java/org/apache/impala/rewrite/CountDistinctToNdvRule.java A fe/src/main/java/org/apache/impala/rewrite/DefaultNdvScaleRule.java M fe/src/test/java/org/apache/impala/analysis/ExprRewriteRulesTest.java M fe/src/test/java/org/apache/impala/analysis/ExprRewriterTest.java 11 files changed, 314 insertions(+), 34 deletions(-) Approvals: Impala Public Jenkins: Looks good to me, approved; Verified -- To view, visit http://gerrit.cloudera.org:8080/17306 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-MessageType: merged Gerrit-Change-Id: I1669858a6e8252e167b464586e8d0b6cb0d0bd50 Gerrit-Change-Number: 17306 Gerrit-PatchSet: 18 Gerrit-Owner: fifteencai Gerrit-Reviewer: Aman Sinha Gerrit-Reviewer: Impala Public Jenkins Gerrit-Reviewer: Qifan Chen Gerrit-Reviewer: Quanlong Huang Gerrit-Reviewer: fifteencai
[Impala-ASF-CR] IMPALA-10445: Adjust NDV's scale with query option
Impala Public Jenkins has posted comments on this change. ( http://gerrit.cloudera.org:8080/17306 ) Change subject: IMPALA-10445: Adjust NDV's scale with query option .. Patch Set 17: Code-Review+2 -- To view, visit http://gerrit.cloudera.org:8080/17306 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-MessageType: comment Gerrit-Change-Id: I1669858a6e8252e167b464586e8d0b6cb0d0bd50 Gerrit-Change-Number: 17306 Gerrit-PatchSet: 17 Gerrit-Owner: fifteencai Gerrit-Reviewer: Aman Sinha Gerrit-Reviewer: Impala Public Jenkins Gerrit-Reviewer: Qifan Chen Gerrit-Reviewer: Quanlong Huang Gerrit-Reviewer: fifteencai Gerrit-Comment-Date: Wed, 21 Apr 2021 03:01:44 + Gerrit-HasComments: No
[Impala-ASF-CR] IMPALA-10445: Adjust NDV's scale with query option
Impala Public Jenkins has posted comments on this change. ( http://gerrit.cloudera.org:8080/17306 ) Change subject: IMPALA-10445: Adjust NDV's scale with query option .. Patch Set 17: Build started: https://jenkins.impala.io/job/gerrit-verify-dryrun/7088/ DRY_RUN=false -- To view, visit http://gerrit.cloudera.org:8080/17306 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-MessageType: comment Gerrit-Change-Id: I1669858a6e8252e167b464586e8d0b6cb0d0bd50 Gerrit-Change-Number: 17306 Gerrit-PatchSet: 17 Gerrit-Owner: fifteencai Gerrit-Reviewer: Aman Sinha Gerrit-Reviewer: Impala Public Jenkins Gerrit-Reviewer: Qifan Chen Gerrit-Reviewer: Quanlong Huang Gerrit-Reviewer: fifteencai Gerrit-Comment-Date: Wed, 21 Apr 2021 03:01:45 + Gerrit-HasComments: No
[Impala-ASF-CR] IMPALA-10445: Adjust NDV's scale with query option
Quanlong Huang has posted comments on this change. ( http://gerrit.cloudera.org:8080/17306 ) Change subject: IMPALA-10445: Adjust NDV's scale with query option .. Patch Set 16: Code-Review+2 > Hi, Can we merge this patch now? Yes. Thanks for the feature! Looking forward to more contributions from you! -- To view, visit http://gerrit.cloudera.org:8080/17306 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-MessageType: comment Gerrit-Change-Id: I1669858a6e8252e167b464586e8d0b6cb0d0bd50 Gerrit-Change-Number: 17306 Gerrit-PatchSet: 16 Gerrit-Owner: fifteencai Gerrit-Reviewer: Aman Sinha Gerrit-Reviewer: Impala Public Jenkins Gerrit-Reviewer: Qifan Chen Gerrit-Reviewer: Quanlong Huang Gerrit-Reviewer: fifteencai Gerrit-Comment-Date: Wed, 21 Apr 2021 03:00:54 + Gerrit-HasComments: No
[Impala-ASF-CR] IMPALA-10445: Adjust NDV's scale with query option
fifteencai has posted comments on this change. ( http://gerrit.cloudera.org:8080/17306 ) Change subject: IMPALA-10445: Adjust NDV's scale with query option .. Patch Set 16: Hi, Can we merge this patch now? -- To view, visit http://gerrit.cloudera.org:8080/17306 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-MessageType: comment Gerrit-Change-Id: I1669858a6e8252e167b464586e8d0b6cb0d0bd50 Gerrit-Change-Number: 17306 Gerrit-PatchSet: 16 Gerrit-Owner: fifteencai Gerrit-Reviewer: Aman Sinha Gerrit-Reviewer: Impala Public Jenkins Gerrit-Reviewer: Qifan Chen Gerrit-Reviewer: Quanlong Huang Gerrit-Reviewer: fifteencai Gerrit-Comment-Date: Wed, 21 Apr 2021 01:03:51 + Gerrit-HasComments: No
[Impala-ASF-CR] IMPALA-10445: Adjust NDV's scale with query option
Quanlong Huang has posted comments on this change. ( http://gerrit.cloudera.org:8080/17306 ) Change subject: IMPALA-10445: Adjust NDV's scale with query option .. Patch Set 16: Code-Review+1 LGTM. Give +1 first in case others want to have a look. -- To view, visit http://gerrit.cloudera.org:8080/17306 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-MessageType: comment Gerrit-Change-Id: I1669858a6e8252e167b464586e8d0b6cb0d0bd50 Gerrit-Change-Number: 17306 Gerrit-PatchSet: 16 Gerrit-Owner: fifteencai Gerrit-Reviewer: Aman Sinha Gerrit-Reviewer: Impala Public Jenkins Gerrit-Reviewer: Qifan Chen Gerrit-Reviewer: Quanlong Huang Gerrit-Reviewer: fifteencai Gerrit-Comment-Date: Mon, 19 Apr 2021 03:53:36 + Gerrit-HasComments: No
[Impala-ASF-CR] IMPALA-10445: Adjust NDV's scale with query option
Impala Public Jenkins has posted comments on this change. ( http://gerrit.cloudera.org:8080/17306 ) Change subject: IMPALA-10445: Adjust NDV's scale with query option .. Patch Set 16: Build Successful https://jenkins.impala.io/job/gerrit-code-review-checks/8589/ : Initial code review checks passed. Use gerrit-verify-dryrun-external or gerrit-verify-dryrun to run full precommit tests. -- To view, visit http://gerrit.cloudera.org:8080/17306 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-MessageType: comment Gerrit-Change-Id: I1669858a6e8252e167b464586e8d0b6cb0d0bd50 Gerrit-Change-Number: 17306 Gerrit-PatchSet: 16 Gerrit-Owner: fifteencai Gerrit-Reviewer: Aman Sinha Gerrit-Reviewer: Impala Public Jenkins Gerrit-Reviewer: Qifan Chen Gerrit-Reviewer: Quanlong Huang Gerrit-Reviewer: fifteencai Gerrit-Comment-Date: Thu, 15 Apr 2021 14:46:09 + Gerrit-HasComments: No
[Impala-ASF-CR] IMPALA-10445: Adjust NDV's scale with query option
fifteencai has uploaded a new patch set (#16). ( http://gerrit.cloudera.org:8080/17306 ) Change subject: IMPALA-10445: Adjust NDV's scale with query option .. IMPALA-10445: Adjust NDV's scale with query option This is a new way to control NDV's scale. Since IMPALA-2658, we can trade memory for more accurate estimation by setting larger `scale` in SQL function NDV(, ). However the use of larger NDV scale requires the modification of SQL queries which may not be practical in certain applications: - Firstly, SQL writers are reluctant to lower that scale. They prone to fill up the scale, which will make the cluster unstable. Especially when there are `group by`s with high cardinalities. So it is wiser to let cluster admin other than sql writer choose appropriate scale. - Secondly, In some application scenarios, queries are stored in DBs. In a BI system, for example, rewriting thousands of SQLs is risky. In this commit, we introduced a new Query Option `DEFAULT_NDV_SCALE` with the following semantics: 1. The allowed value is in the range [1..10]; 2. Previously, the scale used in NDV() functions was fixed at 2. Now the scale is provided by the newly added query options. 3. It does not influence the NDV scale for SQL function NDV(, ) in which the NDV scale is provided by the 2nd argument . We also refactored method `Analyze` to make sure APPX_COUNT_DISTINCT can work with this query option. After this, cluster admins can substitute `count(distinct )` with `ndv(, scale)`. Implementation details: - The default value of DEFAULT_NDV_SCALE is 2, so we won't change the default ndv behavior. - We port `CountDistinctToNdv` transform logic from `SelectStmt.analyze()` to `ExprRewriter`, making it compatible with further rewrite rules. - The newly added rewrite rule `DefaultNdvScaleRule` is applied after `CountDistinctToNdvRule`. Usage: To set a default ndv scale: ``` SET DEFAULT_NDV_SCALE = 10; ``` To unset: ``` SET DEFAULT_NDV_SCALE = 2; ``` Here are test results of a typical workload (cardinality=40,090,650): ++ | Metric| Count Distinct |NDV2|NDV5|NDV10 | ++ | Memory(GB) | 3.83 |1.84|1.85| 1.89 | | Duration(s) | 182.89| 30.22|29.72 | 29.24 | | ErrorRate |0% |1.8%|1.17% | 0.06% | ++ Testing: 1) Added 3 unit test cases in `ExprRewriteRulesTest`. 2) Added 5 unit test cases in `ExprRewriterTest`. 3) Ran all front-end unit test, passed. 4) Added a new query-option test. Change-Id: I1669858a6e8252e167b464586e8d0b6cb0d0bd50 --- M be/src/service/query-options-test.cc M be/src/service/query-options.cc M be/src/service/query-options.h M common/thrift/ImpalaService.thrift M common/thrift/Query.thrift M fe/src/main/java/org/apache/impala/analysis/Analyzer.java M fe/src/main/java/org/apache/impala/analysis/SelectStmt.java A fe/src/main/java/org/apache/impala/rewrite/CountDistinctToNdvRule.java A fe/src/main/java/org/apache/impala/rewrite/DefaultNdvScaleRule.java M fe/src/test/java/org/apache/impala/analysis/ExprRewriteRulesTest.java M fe/src/test/java/org/apache/impala/analysis/ExprRewriterTest.java 11 files changed, 314 insertions(+), 34 deletions(-) git pull ssh://gerrit.cloudera.org:29418/Impala-ASF refs/changes/06/17306/16 -- To view, visit http://gerrit.cloudera.org:8080/17306 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-MessageType: newpatchset Gerrit-Change-Id: I1669858a6e8252e167b464586e8d0b6cb0d0bd50 Gerrit-Change-Number: 17306 Gerrit-PatchSet: 16 Gerrit-Owner: fifteencai Gerrit-Reviewer: Aman Sinha Gerrit-Reviewer: Impala Public Jenkins Gerrit-Reviewer: Qifan Chen Gerrit-Reviewer: Quanlong Huang Gerrit-Reviewer: fifteencai
[Impala-ASF-CR] IMPALA-10445: Adjust NDV's scale with query option
Quanlong Huang has posted comments on this change. (
http://gerrit.cloudera.org:8080/17306 )
Change subject: IMPALA-10445: Adjust NDV's scale with query option
..
Patch Set 15: Code-Review+1
(5 comments)
http://gerrit.cloudera.org:8080/#/c/17306/15/fe/src/test/java/org/apache/impala/analysis/ExprRewriteRulesTest.java
File fe/src/test/java/org/apache/impala/analysis/ExprRewriteRulesTest.java:
http://gerrit.cloudera.org:8080/#/c/17306/15/fe/src/test/java/org/apache/impala/analysis/ExprRewriteRulesTest.java@181
PS15, Line 181:
nit: redudant space
http://gerrit.cloudera.org:8080/#/c/17306/15/fe/src/test/java/org/apache/impala/analysis/ExprRewriteRulesTest.java@184
PS15, Line 184: should
nit: "callers should"
http://gerrit.cloudera.org:8080/#/c/17306/15/fe/src/test/java/org/apache/impala/analysis/ExprRewriteRulesTest.java@188
PS15, Line 188:* expStr: origin expr
:* rules: list of rewrite rules
:* expectedExprStr: expected expr
:* return: Expr
nit: our code style use param comments like these:
/**
*
*
* @param exprStr: original expr
* @param rules: list of rewrite rules
* @param expectedExprStr: expected expr
* @return the rewritten Expr
*/
http://gerrit.cloudera.org:8080/#/c/17306/15/fe/src/test/java/org/apache/impala/analysis/ExprRewriteRulesTest.java@794
PS15, Line 794: session.options().setAppx_count_distinct(true);
: RewritesOk("count(distinct bool_col)", rules,
"ndv(bool_col)");
: }
:
: @Test
: public void testDefaultNdvScaleRule() throws ImpalaException {
: List rules = Lists.newArrayList(
:
org.apache.impala.rewrite.DefaultNdvScaleRule.INSTANCE
: );
: session.options().setDefault_ndv_scale(10);
: RewritesOk("ndv(bool_col)", rules, "ndv(bool_col, 10)");
: }
:
: @Test
: public void testDefaultNdvScaleRuleNotSet() throws
ImpalaException {
: List rules = Lists.newArrayList(
:
org.apache.impala.rewrite.DefaultNdvScaleRule.INSTANCE
: );
: RewritesOk("ndv(bool_col)", rules, null);
: }
:
: @Test
: public void testDefaultNdvScaleRuleSetDefault() throws
ImpalaException {
: List rules = Lists.newArrayList(
:
org.apache.impala.rewrite.DefaultNdvScaleRule.INSTANCE
: );
: session.options().setDefault_ndv_scale(2);
: RewritesOk("ndv(bool_col)", rules, null);
nit: Just like other tests in this file, you can merge these into one test
method since they share the same rule.
http://gerrit.cloudera.org:8080/#/c/17306/15/fe/src/test/java/org/apache/impala/analysis/ExprRewriteRulesTest.java@822
PS15, Line 822:
nit: redundant blank line
--
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Gerrit-Project: Impala-ASF
Gerrit-Branch: master
Gerrit-MessageType: comment
Gerrit-Change-Id: I1669858a6e8252e167b464586e8d0b6cb0d0bd50
Gerrit-Change-Number: 17306
Gerrit-PatchSet: 15
Gerrit-Owner: fifteencai
Gerrit-Reviewer: Aman Sinha
Gerrit-Reviewer: Impala Public Jenkins
Gerrit-Reviewer: Qifan Chen
Gerrit-Reviewer: Quanlong Huang
Gerrit-Reviewer: fifteencai
Gerrit-Comment-Date: Thu, 15 Apr 2021 13:08:20 +
Gerrit-HasComments: Yes
[Impala-ASF-CR] IMPALA-10445: Adjust NDV's scale with query option
fifteencai has posted comments on this change. ( http://gerrit.cloudera.org:8080/17306 ) Change subject: IMPALA-10445: Adjust NDV's scale with query option .. Patch Set 15: Resolved assert problem in newly added unit tests. -- To view, visit http://gerrit.cloudera.org:8080/17306 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-MessageType: comment Gerrit-Change-Id: I1669858a6e8252e167b464586e8d0b6cb0d0bd50 Gerrit-Change-Number: 17306 Gerrit-PatchSet: 15 Gerrit-Owner: fifteencai Gerrit-Reviewer: Aman Sinha Gerrit-Reviewer: Impala Public Jenkins Gerrit-Reviewer: Qifan Chen Gerrit-Reviewer: Quanlong Huang Gerrit-Reviewer: fifteencai Gerrit-Comment-Date: Wed, 14 Apr 2021 15:18:07 + Gerrit-HasComments: No
[Impala-ASF-CR] IMPALA-10445: Adjust NDV's scale with query option
Impala Public Jenkins has posted comments on this change. ( http://gerrit.cloudera.org:8080/17306 ) Change subject: IMPALA-10445: Adjust NDV's scale with query option .. Patch Set 15: Build Successful https://jenkins.impala.io/job/gerrit-code-review-checks/8577/ : Initial code review checks passed. Use gerrit-verify-dryrun-external or gerrit-verify-dryrun to run full precommit tests. -- To view, visit http://gerrit.cloudera.org:8080/17306 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-MessageType: comment Gerrit-Change-Id: I1669858a6e8252e167b464586e8d0b6cb0d0bd50 Gerrit-Change-Number: 17306 Gerrit-PatchSet: 15 Gerrit-Owner: fifteencai Gerrit-Reviewer: Aman Sinha Gerrit-Reviewer: Impala Public Jenkins Gerrit-Reviewer: Qifan Chen Gerrit-Reviewer: Quanlong Huang Gerrit-Reviewer: fifteencai Gerrit-Comment-Date: Wed, 14 Apr 2021 14:50:25 + Gerrit-HasComments: No
[Impala-ASF-CR] IMPALA-10445: Adjust NDV's scale with query option
Impala Public Jenkins has posted comments on this change. ( http://gerrit.cloudera.org:8080/17306 ) Change subject: IMPALA-10445: Adjust NDV's scale with query option .. Patch Set 14: Build Successful https://jenkins.impala.io/job/gerrit-code-review-checks/8576/ : Initial code review checks passed. Use gerrit-verify-dryrun-external or gerrit-verify-dryrun to run full precommit tests. -- To view, visit http://gerrit.cloudera.org:8080/17306 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-MessageType: comment Gerrit-Change-Id: I1669858a6e8252e167b464586e8d0b6cb0d0bd50 Gerrit-Change-Number: 17306 Gerrit-PatchSet: 14 Gerrit-Owner: fifteencai Gerrit-Reviewer: Aman Sinha Gerrit-Reviewer: Impala Public Jenkins Gerrit-Reviewer: Qifan Chen Gerrit-Reviewer: Quanlong Huang Gerrit-Reviewer: fifteencai Gerrit-Comment-Date: Wed, 14 Apr 2021 14:42:23 + Gerrit-HasComments: No
[Impala-ASF-CR] IMPALA-10445: Adjust NDV's scale with query option
fifteencai has uploaded a new patch set (#15). ( http://gerrit.cloudera.org:8080/17306 ) Change subject: IMPALA-10445: Adjust NDV's scale with query option .. IMPALA-10445: Adjust NDV's scale with query option This is a new way to control NDV's scale. Since IMPALA-2658, we can trade memory for more accurate estimation by setting larger `scale` in SQL function NDV(, ). However the use of larger NDV scale requires the modification of SQL queries which may not be practical in certain applications: - Firstly, SQL writers are reluctant to lower that scale. They prone to fill up the scale, which will make the cluster unstable. Especially when there are `group by`s with high cardinalities. So it is wiser to let cluster admin other than sql writer choose appropriate scale. - Secondly, In some application scenarios, queries are stored in DBs. In a BI system, for example, rewriting thousands of SQLs is risky. In this commit, we introduced a new Query Option `DEFAULT_NDV_SCALE` with the following semantics: 1. The allowed value is in the range [1..10]; 2. Previously, the scale used in NDV() functions was fixed at 2. Now the scale is provided by the newly added query options. 3. It does not influence the NDV scale for SQL function NDV(, ) in which the NDV scale is provided by the 2nd argument . We also refactored method `Analyze` to make sure APPX_COUNT_DISTINCT can work with this query option. After this, cluster admins can substitute `count(distinct )` with `ndv(, scale)`. Implementation details: - The default value of DEFAULT_NDV_SCALE is 2, so we won't change the default ndv behavior. - We port `CountDistinctToNdv` transform logic from `SelectStmt.analyze()` to `ExprRewriter`, making it compatible with further rewrite rules. - The newly added rewrite rule `DefaultNdvScaleRule` is applied after `CountDistinctToNdvRule`. Usage: To set a default ndv scale: ``` SET DEFAULT_NDV_SCALE = 10; ``` To unset: ``` SET DEFAULT_NDV_SCALE = 2; ``` Here are test results of a typical workload (cardinality=40,090,650): ++ | Metric| Count Distinct |NDV2|NDV5|NDV10 | ++ | Memory(GB) | 3.83 |1.84|1.85| 1.89 | | Duration(s) | 182.89| 30.22|29.72 | 29.24 | | ErrorRate |0% |1.8%|1.17% | 0.06% | ++ Testing: 1) Added 3 unit test cases in `ExprRewriteRulesTest`. 2) Added 5 unit test cases in `ExprRewriterTest`. 3) Ran all front-end unit test, passed. 4) Added a new query-option test. Change-Id: I1669858a6e8252e167b464586e8d0b6cb0d0bd50 --- M be/src/service/query-options-test.cc M be/src/service/query-options.cc M be/src/service/query-options.h M common/thrift/ImpalaService.thrift M common/thrift/Query.thrift M fe/src/main/java/org/apache/impala/analysis/Analyzer.java M fe/src/main/java/org/apache/impala/analysis/SelectStmt.java A fe/src/main/java/org/apache/impala/rewrite/CountDistinctToNdvRule.java A fe/src/main/java/org/apache/impala/rewrite/DefaultNdvScaleRule.java M fe/src/test/java/org/apache/impala/analysis/ExprRewriteRulesTest.java M fe/src/test/java/org/apache/impala/analysis/ExprRewriterTest.java 11 files changed, 315 insertions(+), 34 deletions(-) git pull ssh://gerrit.cloudera.org:29418/Impala-ASF refs/changes/06/17306/15 -- To view, visit http://gerrit.cloudera.org:8080/17306 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-MessageType: newpatchset Gerrit-Change-Id: I1669858a6e8252e167b464586e8d0b6cb0d0bd50 Gerrit-Change-Number: 17306 Gerrit-PatchSet: 15 Gerrit-Owner: fifteencai Gerrit-Reviewer: Aman Sinha Gerrit-Reviewer: Impala Public Jenkins Gerrit-Reviewer: Qifan Chen Gerrit-Reviewer: Quanlong Huang Gerrit-Reviewer: fifteencai
[Impala-ASF-CR] IMPALA-10445: Adjust NDV's scale with query option
Impala Public Jenkins has posted comments on this change. ( http://gerrit.cloudera.org:8080/17306 ) Change subject: IMPALA-10445: Adjust NDV's scale with query option .. Patch Set 14: (4 comments) http://gerrit.cloudera.org:8080/#/c/17306/14/fe/src/test/java/org/apache/impala/analysis/ExprRewriterTest.java File fe/src/test/java/org/apache/impala/analysis/ExprRewriterTest.java: http://gerrit.cloudera.org:8080/#/c/17306/14/fe/src/test/java/org/apache/impala/analysis/ExprRewriterTest.java@541 PS14, Line 541: //-- line too long (96 > 90) http://gerrit.cloudera.org:8080/#/c/17306/14/fe/src/test/java/org/apache/impala/analysis/ExprRewriterTest.java@546 PS14, Line 546: // CASE 1: DEFAULT_NDV_SCALE=5(same as the value in original sql), APPX_COUNT_DISTINCT=True line too long (95 > 90) http://gerrit.cloudera.org:8080/#/c/17306/14/fe/src/test/java/org/apache/impala/analysis/ExprRewriterTest.java@552 PS14, Line 552: //-- line too long (96 > 90) http://gerrit.cloudera.org:8080/#/c/17306/14/fe/src/test/java/org/apache/impala/analysis/ExprRewriterTest.java@553 PS14, Line 553: String sql1 = "SELECT ndv(id), ndv(id, 5), count(DISTINCT id) FROM functional.alltypes"; line too long (92 > 90) -- To view, visit http://gerrit.cloudera.org:8080/17306 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-MessageType: comment Gerrit-Change-Id: I1669858a6e8252e167b464586e8d0b6cb0d0bd50 Gerrit-Change-Number: 17306 Gerrit-PatchSet: 14 Gerrit-Owner: fifteencai Gerrit-Reviewer: Aman Sinha Gerrit-Reviewer: Impala Public Jenkins Gerrit-Reviewer: Qifan Chen Gerrit-Reviewer: Quanlong Huang Gerrit-Reviewer: fifteencai Gerrit-Comment-Date: Wed, 14 Apr 2021 14:23:45 + Gerrit-HasComments: Yes
[Impala-ASF-CR] IMPALA-10445: Adjust NDV's scale with query option
fifteencai has uploaded a new patch set (#14). ( http://gerrit.cloudera.org:8080/17306 ) Change subject: IMPALA-10445: Adjust NDV's scale with query option .. IMPALA-10445: Adjust NDV's scale with query option This is a new way to control NDV's scale. Since IMPALA-2658, we can trade memory for more accurate estimation by setting larger `scale` in SQL function NDV(, ). However the use of larger NDV scale requires the modification of SQL queries which may not be practical in certain applications: - Firstly, SQL writers are reluctant to lower that scale. They prone to fill up the scale, which will make the cluster unstable. Especially when there are `group by`s with high cardinalities. So it is wiser to let cluster admin other than sql writer choose appropriate scale. - Secondly, In some application scenarios, queries are stored in DBs. In a BI system, for example, rewriting thousands of SQLs is risky. In this commit, we introduced a new Query Option `DEFAULT_NDV_SCALE` with the following semantics: 1. The allowed value is in the range [1..10]; 2. Previously, the scale used in NDV() functions was fixed at 2. Now the scale is provided by the newly added query options. 3. It does not influence the NDV scale for SQL function NDV(, ) in which the NDV scale is provided by the 2nd argument . We also refactored method `Analyze` to make sure APPX_COUNT_DISTINCT can work with this query option. After this, cluster admins can substitute `count(distinct )` with `ndv(, scale)`. Implementation details: - The default value of DEFAULT_NDV_SCALE is 2, so we won't change the default ndv behavior. - We port `CountDistinctToNdv` transform logic from `SelectStmt.analyze()` to `ExprRewriter`, making it compatible with further rewrite rules. - The newly added rewrite rule `DefaultNdvScaleRule` is applied after `CountDistinctToNdvRule`. Usage: To set a default ndv scale: ``` SET DEFAULT_NDV_SCALE = 10; ``` To unset: ``` SET DEFAULT_NDV_SCALE = 2; ``` Here are test results of a typical workload (cardinality=40,090,650): ++ | Metric| Count Distinct |NDV2|NDV5|NDV10 | ++ | Memory(GB) | 3.83 |1.84|1.85| 1.89 | | Duration(s) | 182.89| 30.22|29.72 | 29.24 | | ErrorRate |0% |1.8%|1.17% | 0.06% | ++ Testing: 1) Added 3 unit test cases in `ExprRewriteRulesTest`. 2) Added 5 unit test cases in `ExprRewriterTest`. 3) Ran all front-end unit test, passed. 4) Added a new query-option test. Change-Id: I1669858a6e8252e167b464586e8d0b6cb0d0bd50 --- M be/src/service/query-options-test.cc M be/src/service/query-options.cc M be/src/service/query-options.h M common/thrift/ImpalaService.thrift M common/thrift/Query.thrift M fe/src/main/java/org/apache/impala/analysis/Analyzer.java M fe/src/main/java/org/apache/impala/analysis/SelectStmt.java A fe/src/main/java/org/apache/impala/rewrite/CountDistinctToNdvRule.java A fe/src/main/java/org/apache/impala/rewrite/DefaultNdvScaleRule.java M fe/src/test/java/org/apache/impala/analysis/ExprRewriteRulesTest.java M fe/src/test/java/org/apache/impala/analysis/ExprRewriterTest.java 11 files changed, 312 insertions(+), 34 deletions(-) git pull ssh://gerrit.cloudera.org:29418/Impala-ASF refs/changes/06/17306/14 -- To view, visit http://gerrit.cloudera.org:8080/17306 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-MessageType: newpatchset Gerrit-Change-Id: I1669858a6e8252e167b464586e8d0b6cb0d0bd50 Gerrit-Change-Number: 17306 Gerrit-PatchSet: 14 Gerrit-Owner: fifteencai Gerrit-Reviewer: Aman Sinha Gerrit-Reviewer: Impala Public Jenkins Gerrit-Reviewer: Qifan Chen Gerrit-Reviewer: Quanlong Huang Gerrit-Reviewer: fifteencai
[Impala-ASF-CR] IMPALA-10445: Adjust NDV's scale with query option
Impala Public Jenkins has posted comments on this change. ( http://gerrit.cloudera.org:8080/17306 ) Change subject: IMPALA-10445: Adjust NDV's scale with query option .. Patch Set 13: Build Successful https://jenkins.impala.io/job/gerrit-code-review-checks/8575/ : Initial code review checks passed. Use gerrit-verify-dryrun-external or gerrit-verify-dryrun to run full precommit tests. -- To view, visit http://gerrit.cloudera.org:8080/17306 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-MessageType: comment Gerrit-Change-Id: I1669858a6e8252e167b464586e8d0b6cb0d0bd50 Gerrit-Change-Number: 17306 Gerrit-PatchSet: 13 Gerrit-Owner: fifteencai Gerrit-Reviewer: Aman Sinha Gerrit-Reviewer: Impala Public Jenkins Gerrit-Reviewer: Qifan Chen Gerrit-Reviewer: Quanlong Huang Gerrit-Reviewer: fifteencai Gerrit-Comment-Date: Wed, 14 Apr 2021 14:20:33 + Gerrit-HasComments: No
[Impala-ASF-CR] IMPALA-10445: Adjust NDV's scale with query option
Impala Public Jenkins has posted comments on this change. ( http://gerrit.cloudera.org:8080/17306 ) Change subject: IMPALA-10445: Adjust NDV's scale with query option .. Patch Set 13: (7 comments) http://gerrit.cloudera.org:8080/#/c/17306/13/fe/src/test/java/org/apache/impala/analysis/ExprRewriteRulesTest.java File fe/src/test/java/org/apache/impala/analysis/ExprRewriteRulesTest.java: http://gerrit.cloudera.org:8080/#/c/17306/13/fe/src/test/java/org/apache/impala/analysis/ExprRewriteRulesTest.java@180 PS13, Line 180: // Given a list of `rule`, this function checks whether the rewritten is as expected line too long (93 > 90) http://gerrit.cloudera.org:8080/#/c/17306/13/fe/src/test/java/org/apache/impala/analysis/ExprRewriteRulesTest.java@181 PS13, Line 181: // Caution: if no rule in `rules` is expected to be fired, should set expectedExprStr to null line too long (95 > 90) http://gerrit.cloudera.org:8080/#/c/17306/13/fe/src/test/java/org/apache/impala/analysis/ExprRewriteRulesTest.java@182 PS13, Line 182: // or "NULL". otherwise, this function would throw an exception like "Rule xxx didn't fire" line too long (93 > 90) http://gerrit.cloudera.org:8080/#/c/17306/13/fe/src/test/java/org/apache/impala/analysis/ExprRewriterTest.java File fe/src/test/java/org/apache/impala/analysis/ExprRewriterTest.java: http://gerrit.cloudera.org:8080/#/c/17306/13/fe/src/test/java/org/apache/impala/analysis/ExprRewriterTest.java@541 PS13, Line 541: //-- line too long (96 > 90) http://gerrit.cloudera.org:8080/#/c/17306/13/fe/src/test/java/org/apache/impala/analysis/ExprRewriterTest.java@546 PS13, Line 546: // CASE 1: DEFAULT_NDV_SCALE=5(same as the value in original sql), APPX_COUNT_DISTINCT=True line too long (95 > 90) http://gerrit.cloudera.org:8080/#/c/17306/13/fe/src/test/java/org/apache/impala/analysis/ExprRewriterTest.java@552 PS13, Line 552: //-- line too long (96 > 90) http://gerrit.cloudera.org:8080/#/c/17306/13/fe/src/test/java/org/apache/impala/analysis/ExprRewriterTest.java@553 PS13, Line 553: String sql1 = "SELECT ndv(id), ndv(id, 5), count(DISTINCT id) FROM functional.alltypes"; line too long (92 > 90) -- To view, visit http://gerrit.cloudera.org:8080/17306 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-MessageType: comment Gerrit-Change-Id: I1669858a6e8252e167b464586e8d0b6cb0d0bd50 Gerrit-Change-Number: 17306 Gerrit-PatchSet: 13 Gerrit-Owner: fifteencai Gerrit-Reviewer: Aman Sinha Gerrit-Reviewer: Impala Public Jenkins Gerrit-Reviewer: Qifan Chen Gerrit-Reviewer: Quanlong Huang Gerrit-Reviewer: fifteencai Gerrit-Comment-Date: Wed, 14 Apr 2021 14:01:45 + Gerrit-HasComments: Yes
[Impala-ASF-CR] IMPALA-10445: Adjust NDV's scale with query option
fifteencai has uploaded a new patch set (#13). ( http://gerrit.cloudera.org:8080/17306 ) Change subject: IMPALA-10445: Adjust NDV's scale with query option .. IMPALA-10445: Adjust NDV's scale with query option This is a new way to control NDV's scale. Since IMPALA-2658, we can trade memory for more accurate estimation by setting larger `scale` in SQL function NDV(, ). However the use of larger NDV scale requires the modification of SQL queries which may not be practical in certain applications: - Firstly, SQL writers are reluctant to lower that scale. They prone to fill up the scale, which will make the cluster unstable. Especially when there are `group by`s with high cardinalities. So it is wiser to let cluster admin other than sql writer choose appropriate scale. - Secondly, In some application scenarios, queries are stored in DBs. In a BI system, for example, rewriting thousands of SQLs is risky. In this commit, we introduced a new Query Option `DEFAULT_NDV_SCALE` with the following semantics: 1. The allowed value is in the range [1..10]; 2. Previously, the scale used in NDV() functions was fixed at 2. Now the scale is provided by the newly added query options. 3. It does not influence the NDV scale for SQL function NDV(, ) in which the NDV scale is provided by the 2nd argument . We also refactored method `Analyze` to make sure APPX_COUNT_DISTINCT can work with this query option. After this, cluster admins can substitute `count(distinct )` with `ndv(, scale)`. Implementation details: - The default value of DEFAULT_NDV_SCALE is 2, so we won't change the default ndv behavior. - We port `CountDistinctToNdv` transform logic from `SelectStmt.analyze()` to `ExprRewriter`, making it compatible with further rewrite rules. - The newly added rewrite rule `DefaultNdvScaleRule` is applied after `CountDistinctToNdvRule`. Usage: To set a default ndv scale: ``` SET DEFAULT_NDV_SCALE = 10; ``` To unset: ``` SET DEFAULT_NDV_SCALE = 2; ``` Here are test results of a typical workload (cardinality=40,090,650): ++ | Metric| Count Distinct |NDV2|NDV5|NDV10 | ++ | Memory(GB) | 3.83 |1.84|1.85| 1.89 | | Duration(s) | 182.89| 30.22|29.72 | 29.24 | | ErrorRate |0% |1.8%|1.17% | 0.06% | ++ Testing: 1) Added 3 unit test cases in `ExprRewriteRulesTest`. 2) Added 5 unit test cases in `ExprRewriterTest`. 3) Ran all front-end unit test, passed. 4) Added a new query-option test. Change-Id: I1669858a6e8252e167b464586e8d0b6cb0d0bd50 --- M be/src/service/query-options-test.cc M be/src/service/query-options.cc M be/src/service/query-options.h M common/thrift/ImpalaService.thrift M common/thrift/Query.thrift M fe/src/main/java/org/apache/impala/analysis/Analyzer.java M fe/src/main/java/org/apache/impala/analysis/SelectStmt.java A fe/src/main/java/org/apache/impala/rewrite/CountDistinctToNdvRule.java A fe/src/main/java/org/apache/impala/rewrite/DefaultNdvScaleRule.java M fe/src/test/java/org/apache/impala/analysis/ExprRewriteRulesTest.java M fe/src/test/java/org/apache/impala/analysis/ExprRewriterTest.java 11 files changed, 302 insertions(+), 34 deletions(-) git pull ssh://gerrit.cloudera.org:29418/Impala-ASF refs/changes/06/17306/13 -- To view, visit http://gerrit.cloudera.org:8080/17306 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-MessageType: newpatchset Gerrit-Change-Id: I1669858a6e8252e167b464586e8d0b6cb0d0bd50 Gerrit-Change-Number: 17306 Gerrit-PatchSet: 13 Gerrit-Owner: fifteencai Gerrit-Reviewer: Aman Sinha Gerrit-Reviewer: Impala Public Jenkins Gerrit-Reviewer: Qifan Chen Gerrit-Reviewer: Quanlong Huang Gerrit-Reviewer: fifteencai
[Impala-ASF-CR] IMPALA-10445: Adjust NDV's scale with query option
Qifan Chen has posted comments on this change. ( http://gerrit.cloudera.org:8080/17306 ) Change subject: IMPALA-10445: Adjust NDV's scale with query option .. Patch Set 12: Code-Review+1 Looks good! -- To view, visit http://gerrit.cloudera.org:8080/17306 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-MessageType: comment Gerrit-Change-Id: I1669858a6e8252e167b464586e8d0b6cb0d0bd50 Gerrit-Change-Number: 17306 Gerrit-PatchSet: 12 Gerrit-Owner: fifteencai Gerrit-Reviewer: Aman Sinha Gerrit-Reviewer: Impala Public Jenkins Gerrit-Reviewer: Qifan Chen Gerrit-Reviewer: Quanlong Huang Gerrit-Reviewer: fifteencai Gerrit-Comment-Date: Wed, 14 Apr 2021 13:01:29 + Gerrit-HasComments: No
[Impala-ASF-CR] IMPALA-10445: Adjust NDV's scale with query option
Quanlong Huang has posted comments on this change. ( http://gerrit.cloudera.org:8080/17306 ) Change subject: IMPALA-10445: Adjust NDV's scale with query option .. Patch Set 12: Code-Review+1 -- To view, visit http://gerrit.cloudera.org:8080/17306 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-MessageType: comment Gerrit-Change-Id: I1669858a6e8252e167b464586e8d0b6cb0d0bd50 Gerrit-Change-Number: 17306 Gerrit-PatchSet: 12 Gerrit-Owner: fifteencai Gerrit-Reviewer: Aman Sinha Gerrit-Reviewer: Impala Public Jenkins Gerrit-Reviewer: Qifan Chen Gerrit-Reviewer: Quanlong Huang Gerrit-Reviewer: fifteencai Gerrit-Comment-Date: Wed, 14 Apr 2021 08:46:04 + Gerrit-HasComments: No
[Impala-ASF-CR] IMPALA-10445: Adjust NDV's scale with query option
Impala Public Jenkins has posted comments on this change. ( http://gerrit.cloudera.org:8080/17306 ) Change subject: IMPALA-10445: Adjust NDV's scale with query option .. Patch Set 11: Build Failed https://jenkins.impala.io/job/gerrit-code-review-checks/8570/ : Initial code review checks failed. See linked job for details on the failure. -- To view, visit http://gerrit.cloudera.org:8080/17306 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-MessageType: comment Gerrit-Change-Id: I1669858a6e8252e167b464586e8d0b6cb0d0bd50 Gerrit-Change-Number: 17306 Gerrit-PatchSet: 11 Gerrit-Owner: fifteencai Gerrit-Reviewer: Aman Sinha Gerrit-Reviewer: Impala Public Jenkins Gerrit-Reviewer: Qifan Chen Gerrit-Reviewer: Quanlong Huang Gerrit-Reviewer: fifteencai Gerrit-Comment-Date: Wed, 14 Apr 2021 08:15:09 + Gerrit-HasComments: No
[Impala-ASF-CR] IMPALA-10445: Adjust NDV's scale with query option
fifteencai has uploaded a new patch set (#12). ( http://gerrit.cloudera.org:8080/17306 ) Change subject: IMPALA-10445: Adjust NDV's scale with query option .. IMPALA-10445: Adjust NDV's scale with query option This is a new way to control NDV's scale. Since IMPALA-2658, we can trade memory for more accurate estimation by setting larger `scale` in SQL function NDV(, ). However the use of larger NDV scale requires the modification of SQL queries which may not be practical in certain applications: - Firstly, SQL writers are reluctant to lower that scale. They prone to fill up the scale, which will make the cluster unstable. Especially when there are `group by`s with high cardinalities. So it is wiser to let cluster admin other than sql writer choose appropriate scale. - Secondly, In some application scenarios, queries are stored in DBs. In a BI system, for example, rewriting thousands of SQLs is risky. In this commit, we introduced a new Query Option `DEFAULT_NDV_SCALE` with the following semantics: 1. The allowed value is in the range [1..10]; 2. Previously, the scale used in NDV() functions was fixed at 2. Now the scale is provided by the newly added query options. 3. It does not influence the NDV scale for SQL function NDV(, ) in which the NDV scale is provided by the 2nd argument . We also refactored method `Analyze` to make sure APPX_COUNT_DISTINCT can work with this query option. After this, cluster admins can substitute `count(distinct )` with `ndv(, scale)`. Implementation details: - The default value of DEFAULT_NDV_SCALE is 2, so we won't change the default ndv behavior. - We port `CountDistinctToNdv` transform logic from `SelectStmt.analyze()` to `ExprRewriter`, making it compatible with further rewrite rules. - The newly added rewrite rule `DefaultNdvScaleRule` is applied after `CountDistinctToNdvRule`. Usage: To set a default ndv scale: ``` SET DEFAULT_NDV_SCALE = 10; ``` To unset: ``` SET DEFAULT_NDV_SCALE = 2; ``` Here are test results of a typical workload (cardinality=40,090,650): ++ | Metric| Count Distinct |NDV2|NDV5|NDV10 | ++ | Memory(GB) | 3.83 |1.84|1.85| 1.89 | | Duration(s) | 182.89| 30.22|29.72 | 29.24 | | ErrorRate |0% |1.8%|1.17% | 0.06% | ++ Testing: 1) Added 3 unit test cases in `ExprRewriteRulesTest`. 2) Added 5 unit test cases in `ExprRewriterTest`. 3) Ran all front-end unit test, passed. 4) Added a new query-option test. Change-Id: I1669858a6e8252e167b464586e8d0b6cb0d0bd50 --- M be/src/service/query-options-test.cc M be/src/service/query-options.cc M be/src/service/query-options.h M common/thrift/ImpalaService.thrift M common/thrift/Query.thrift M fe/src/main/java/org/apache/impala/analysis/Analyzer.java M fe/src/main/java/org/apache/impala/analysis/SelectStmt.java A fe/src/main/java/org/apache/impala/rewrite/CountDistinctToNdvRule.java A fe/src/main/java/org/apache/impala/rewrite/DefaultNdvScaleRule.java M fe/src/test/java/org/apache/impala/analysis/ExprRewriteRulesTest.java M fe/src/test/java/org/apache/impala/analysis/ExprRewriterTest.java 11 files changed, 298 insertions(+), 34 deletions(-) git pull ssh://gerrit.cloudera.org:29418/Impala-ASF refs/changes/06/17306/12 -- To view, visit http://gerrit.cloudera.org:8080/17306 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-MessageType: newpatchset Gerrit-Change-Id: I1669858a6e8252e167b464586e8d0b6cb0d0bd50 Gerrit-Change-Number: 17306 Gerrit-PatchSet: 12 Gerrit-Owner: fifteencai Gerrit-Reviewer: Aman Sinha Gerrit-Reviewer: Impala Public Jenkins Gerrit-Reviewer: Qifan Chen Gerrit-Reviewer: Quanlong Huang Gerrit-Reviewer: fifteencai
[Impala-ASF-CR] IMPALA-10445: Adjust NDV's scale with query option
Qifan Chen has posted comments on this change. ( http://gerrit.cloudera.org:8080/17306 ) Change subject: IMPALA-10445: Adjust NDV's scale with query option .. Patch Set 11: (2 comments) Looks good! http://gerrit.cloudera.org:8080/#/c/17306/11//COMMIT_MSG Commit Message: http://gerrit.cloudera.org:8080/#/c/17306/11//COMMIT_MSG@14 PS11, Line 14: y nit: queries http://gerrit.cloudera.org:8080/#/c/17306/11/fe/src/test/java/org/apache/impala/analysis/ExprRewriterTest.java File fe/src/test/java/org/apache/impala/analysis/ExprRewriterTest.java: http://gerrit.cloudera.org:8080/#/c/17306/11/fe/src/test/java/org/apache/impala/analysis/ExprRewriterTest.java@539 PS11, Line 539: } The above tests look good! Can we add several more to test the combination of the two new rules: 1. SELECT count(DISTINCT id), ndv(id) FROM functional.alltypes 2. setDefault_ndv_scale(9) and then SELECT count(DISTINCT id), ndv(id) FROM functional.alltypes 3. setDefault_ndv_scale(5) and then SELECT count(DISTINCT id), ndv(id), ndv(id, 10) FROM functional.alltypes 3. setDefault_ndv_scale(5) and then SELECT ndv(id, 10), count(DISTINCT id), ndv(id) FROM functional.alltypes 4. setAppx_count_distinct(true);setDefault_ndv_scale(9) and then SELECT count(DISTINCT id), ndv(id) FROM functional.alltypes -- To view, visit http://gerrit.cloudera.org:8080/17306 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-MessageType: comment Gerrit-Change-Id: I1669858a6e8252e167b464586e8d0b6cb0d0bd50 Gerrit-Change-Number: 17306 Gerrit-PatchSet: 11 Gerrit-Owner: fifteencai Gerrit-Reviewer: Aman Sinha Gerrit-Reviewer: Impala Public Jenkins Gerrit-Reviewer: Qifan Chen Gerrit-Reviewer: Quanlong Huang Gerrit-Reviewer: fifteencai Gerrit-Comment-Date: Wed, 14 Apr 2021 02:08:08 + Gerrit-HasComments: Yes
[Impala-ASF-CR] IMPALA-10445: Adjust NDV's scale with query option
fifteencai has posted comments on this change. ( http://gerrit.cloudera.org:8080/17306 ) Change subject: IMPALA-10445: Adjust NDV's scale with query option .. Patch Set 11: Thanks a lot to Quanlong and Qifan !!! I have reworded the commit msg and added unit tests. Please take a look. -- To view, visit http://gerrit.cloudera.org:8080/17306 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-MessageType: comment Gerrit-Change-Id: I1669858a6e8252e167b464586e8d0b6cb0d0bd50 Gerrit-Change-Number: 17306 Gerrit-PatchSet: 11 Gerrit-Owner: fifteencai Gerrit-Reviewer: Aman Sinha Gerrit-Reviewer: Impala Public Jenkins Gerrit-Reviewer: Qifan Chen Gerrit-Reviewer: Quanlong Huang Gerrit-Reviewer: fifteencai Gerrit-Comment-Date: Wed, 14 Apr 2021 00:56:01 + Gerrit-HasComments: No
[Impala-ASF-CR] IMPALA-10445: Adjust NDV's scale with query option
fifteencai has uploaded a new patch set (#11). ( http://gerrit.cloudera.org:8080/17306 ) Change subject: IMPALA-10445: Adjust NDV's scale with query option .. IMPALA-10445: Adjust NDV's scale with query option This is a new way to control NDV's scale. Since IMPALA-2658, we can trade memory for more accurate estimation by setting larger `scale` in SQL function NDV(, ). However the use of larger NDV scale requires the modification of SQL query which may not be practical in certain applications: - Firstly, SQL writers are reluctant to lower that scale. They prone to fill up the scale, which will make the cluster unstable. Especially when there are `group by`s with high cardinalities. So it is wiser to let cluster admin other than sql writer choose appropriate scale. - Secondly, In some application scenarios, queries are stored in DBs. In a BI system, for example, rewriting thousands of SQLs is risky. In this commit, we introduced a new Query Option `DEFAULT_NDV_SCALE` with the following semantics: 1. The allowed value is in the range [1..10]; 2. Previously, the scale used in NDV() functions was fixed at 2. Now the scale is provided by the newly added query options. 3. It does not influence the NDV scale for SQL function NDV(, ) in which the NDV scale is provided by the 2nd argument . We also refactored method `Analyze` to make sure APPX_COUNT_DISTINCT can work with this query option. After this, cluster admins can substitute `count(distinct )` with `ndv(, scale)`. Implementation details: - The default value of DEFAULT_NDV_SCALE is 2, so we won't change the default ndv behavior. - We port `CountDistinctToNdv` transform logic from `SelectStmt.analyze()` to `ExprRewriter`, making it compatible with further rewrite rules. - The newly added rewrite rule `DefaultNdvScaleRule` is applied after `CountDistinctToNdvRule`. Usage: To set a default ndv scale: ``` SET DEFAULT_NDV_SCALE = 10; ``` To unset: ``` SET DEFAULT_NDV_SCALE = 2; ``` Here are test results of a typical workload (cardinality=40,090,650): ++ | Metric| Count Distinct |NDV2|NDV5|NDV10 | ++ | Memory(GB) | 3.83 |1.84|1.85| 1.89 | | Duration(s) | 182.89| 30.22|29.72 | 29.24 | | ErrorRate |0% |1.8%|1.17% | 0.06% | ++ Testing: 1) Added 3 unit test cases in `ExprRewriteRulesTest`. 2) Added 5 unit test cases in `ExprRewriterTest`. 3) Ran all front-end unit test, passed. 4) Added a new query-option test. Change-Id: I1669858a6e8252e167b464586e8d0b6cb0d0bd50 --- M be/src/service/query-options-test.cc M be/src/service/query-options.cc M be/src/service/query-options.h M common/thrift/ImpalaService.thrift M common/thrift/Query.thrift M fe/src/main/java/org/apache/impala/analysis/Analyzer.java M fe/src/main/java/org/apache/impala/analysis/SelectStmt.java A fe/src/main/java/org/apache/impala/rewrite/CountDistinctToNdvRule.java A fe/src/main/java/org/apache/impala/rewrite/DefaultNdvScaleRule.java M fe/src/test/java/org/apache/impala/analysis/ExprRewriteRulesTest.java M fe/src/test/java/org/apache/impala/analysis/ExprRewriterTest.java 11 files changed, 252 insertions(+), 34 deletions(-) git pull ssh://gerrit.cloudera.org:29418/Impala-ASF refs/changes/06/17306/11 -- To view, visit http://gerrit.cloudera.org:8080/17306 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-MessageType: newpatchset Gerrit-Change-Id: I1669858a6e8252e167b464586e8d0b6cb0d0bd50 Gerrit-Change-Number: 17306 Gerrit-PatchSet: 11 Gerrit-Owner: fifteencai Gerrit-Reviewer: Aman Sinha Gerrit-Reviewer: Impala Public Jenkins Gerrit-Reviewer: Qifan Chen Gerrit-Reviewer: Quanlong Huang
[Impala-ASF-CR] IMPALA-10445: Adjust NDV's scale with query option
Qifan Chen has posted comments on this change. ( http://gerrit.cloudera.org:8080/17306 ) Change subject: IMPALA-10445: Adjust NDV's scale with query option .. Patch Set 9: (1 comment) http://gerrit.cloudera.org:8080/#/c/17306/9/fe/src/main/java/org/apache/impala/rewrite/DefaultNdvScaleRule.java File fe/src/main/java/org/apache/impala/rewrite/DefaultNdvScaleRule.java: http://gerrit.cloudera.org:8080/#/c/17306/9/fe/src/main/java/org/apache/impala/rewrite/DefaultNdvScaleRule.java@38 PS9, Line 38: DefaultNdvScaleRule > I wonder if this rule can be merged to the CountDistinctToNdvRule. That is, It seems this rule by itself is also important to transform NDV() to NDV(, ) under the table when transform count(distinct) to NDV() is not needed. I am OK with keeping this rule. -- To view, visit http://gerrit.cloudera.org:8080/17306 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-MessageType: comment Gerrit-Change-Id: I1669858a6e8252e167b464586e8d0b6cb0d0bd50 Gerrit-Change-Number: 17306 Gerrit-PatchSet: 9 Gerrit-Owner: fifteencai Gerrit-Reviewer: Aman Sinha Gerrit-Reviewer: Impala Public Jenkins Gerrit-Reviewer: Qifan Chen Gerrit-Reviewer: Quanlong Huang Gerrit-Comment-Date: Tue, 13 Apr 2021 21:18:47 + Gerrit-HasComments: Yes
[Impala-ASF-CR] IMPALA-10445: Adjust NDV's scale with query option
Qifan Chen has posted comments on this change. ( http://gerrit.cloudera.org:8080/17306 ) Change subject: IMPALA-10445: Adjust NDV's scale with query option .. Patch Set 9: (6 comments) Looks good to me! http://gerrit.cloudera.org:8080/#/c/17306/9//COMMIT_MSG Commit Message: http://gerrit.cloudera.org:8080/#/c/17306/9//COMMIT_MSG@12 PS9, Line 12: estimation by setting larger `scale`. That scale is decided by SQL in SQL function NDV(, ) http://gerrit.cloudera.org:8080/#/c/17306/9//COMMIT_MSG@11 PS9, Line 11: Since IMPALA-2658, we can trade memory for more accurate : estimation by setting larger `scale`. That scale is decided by SQL : writers. However, it is a bumpy road for cluster admins to allow for : larger scales. Here lies 2 reasons: May rewrite the sentence as follows. Since IMPALA-2658, we can trade memory for more accurate estimation by setting larger NDV scale in SQL function NDV(, ). However, the use of larger NDV scale requires the modification of the NDV function in queries which may not be practical in certain applications. http://gerrit.cloudera.org:8080/#/c/17306/9//COMMIT_MSG@24 PS9, Line 24: In this commit, we introduced a new Query Option `DEFAULT_NDV_SCALE`. : During to the advantage of query option, Cluster admins can either tune : 1 desired query, or influence upcoming queries by placing a default : query option in a dynamic resource pool. This paragraph can be rewritten as follows. In this commit, we introduced a new Query Option `DEFAULT_NDV_SCALE` with the following semantics. 1. The allowed value is in the range [2..10]; 2. The value of the query option is the default NDV scale for the SQL function of form NDV(). Previously, the NDV scale used in such functions is fixed at 2; 3. It does not influence the NDV scale for SQL function NDV(, ) in which the NDV scale is provided by the 2nd argument . http://gerrit.cloudera.org:8080/#/c/17306/9/common/thrift/ImpalaService.thrift File common/thrift/ImpalaService.thrift: http://gerrit.cloudera.org:8080/#/c/17306/9/common/thrift/ImpalaService.thrift@655 PS9, Line 655: , make it easier to change NDV's scale may change to " to SQL NDV function NDV(. http://gerrit.cloudera.org:8080/#/c/17306/9/fe/src/main/java/org/apache/impala/rewrite/CountDistinctToNdvRule.java File fe/src/main/java/org/apache/impala/rewrite/CountDistinctToNdvRule.java: http://gerrit.cloudera.org:8080/#/c/17306/9/fe/src/main/java/org/apache/impala/rewrite/CountDistinctToNdvRule.java@58 PS9, Line 58: Do function name substitution Probably should say "Create the substituted form". http://gerrit.cloudera.org:8080/#/c/17306/9/fe/src/main/java/org/apache/impala/rewrite/DefaultNdvScaleRule.java File fe/src/main/java/org/apache/impala/rewrite/DefaultNdvScaleRule.java: http://gerrit.cloudera.org:8080/#/c/17306/9/fe/src/main/java/org/apache/impala/rewrite/DefaultNdvScaleRule.java@38 PS9, Line 38: DefaultNdvScaleRule I wonder if this rule can be merged to the CountDistinctToNdvRule. That is, if APPX_COUNT_DISTINCT query option is set, we fire that rule. Within that rule, we check for query option DEFAULT_NDV_SCALE and form NDV() function in two ways: NDV() if the value of DEFAULT_NDV_SCALE is 2, or NDV(, ) otherwise. -- To view, visit http://gerrit.cloudera.org:8080/17306 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-MessageType: comment Gerrit-Change-Id: I1669858a6e8252e167b464586e8d0b6cb0d0bd50 Gerrit-Change-Number: 17306 Gerrit-PatchSet: 9 Gerrit-Owner: fifteencai Gerrit-Reviewer: Aman Sinha Gerrit-Reviewer: Impala Public Jenkins Gerrit-Reviewer: Qifan Chen Gerrit-Reviewer: Quanlong Huang Gerrit-Comment-Date: Tue, 13 Apr 2021 17:40:26 + Gerrit-HasComments: Yes
[Impala-ASF-CR] IMPALA-10445: Adjust NDV's scale with query option
Impala Public Jenkins has posted comments on this change. ( http://gerrit.cloudera.org:8080/17306 ) Change subject: IMPALA-10445: Adjust NDV's scale with query option .. Patch Set 9: Build Successful https://jenkins.impala.io/job/gerrit-code-review-checks/8559/ : Initial code review checks passed. Use gerrit-verify-dryrun-external or gerrit-verify-dryrun to run full precommit tests. -- To view, visit http://gerrit.cloudera.org:8080/17306 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-MessageType: comment Gerrit-Change-Id: I1669858a6e8252e167b464586e8d0b6cb0d0bd50 Gerrit-Change-Number: 17306 Gerrit-PatchSet: 9 Gerrit-Owner: fifteencai Gerrit-Reviewer: Aman Sinha Gerrit-Reviewer: Impala Public Jenkins Gerrit-Reviewer: Qifan Chen Gerrit-Reviewer: Quanlong Huang Gerrit-Comment-Date: Tue, 13 Apr 2021 10:22:04 + Gerrit-HasComments: No
[Impala-ASF-CR] IMPALA-10445: Adjust NDV's scale with query option
fifteencai has uploaded a new patch set (#9). ( http://gerrit.cloudera.org:8080/17306 ) Change subject: IMPALA-10445: Adjust NDV's scale with query option .. IMPALA-10445: Adjust NDV's scale with query option This is a new way to control NDV's scale. Since IMPALA-2658, we can trade memory for more accurate estimation by setting larger `scale`. That scale is decided by SQL writers. However, it is a bumpy road for cluster admins to allow for larger scales. Here lies 2 reasons: - Firstly, SQL writers are reluctant to low the scale. They prone to fill up the scale, which will make the cluster unstable, especially when there are `group by`s with high cardinalities. So it is wiser to let cluster admin instead of sql writer choose appropriate scale. - Secondly, In some application scenarios, queries are stored in DBs. In a BI system, for example, rewriting thousands of SQLs is risky. In this commit, we introduced a new Query Option `DEFAULT_NDV_SCALE`. During to the advantage of query option, Cluster admins can either tune 1 desired query, or influence upcoming queries by placing a default query option in a dynamic resource pool. We also refactored method `Analyze` to make sure APPX_COUNT_DISTINCT can work with this query option. After this, cluster admins can degrade service level by transforming `count(distinct id)` to `ndv(id, scale)`. Implementation details: - The default value of DEFAULT_NDV_SCALE is 2, so we won't change the default ndv behavior. - We port `CountDistinctToNdv` transform logic from `SelectStmt.analyze()` to `ExprRewriter`, making it compatible with further rewrite rules. - The newly added rewrite rule `DefaultNdvScaleRule` is applied after `CountDistinctToNdvRule`. Usage: To set a default ndv scale: ``` SET DEFAULT_NDV_SCALE = 10; -- ranges from 1 to 10, both inclusive. ``` To unset: ``` SET DEFAULT_NDV_SCALE = 2; ``` Here are test results of a typical workload (cardinality=40,090,650): ++ | Metric| Count Distinct |NDV2|NDV5|NDV10 | ++ | Memory(GB) | 3.83 |1.84|1.85| 1.89 | | Duration(s) | 182.89| 30.22|29.72 | 29.24 | | ErrorRate |0% |1.8%|1.17% | 0.06% | ++ Testing: 1) Added 3 unit test cases in `ExprRewriteRulesTest`. 2) Added 5 unit test cases in `ExprRewriterTest`. 3) Ran all front-end unit test, passed. 4) Added a new query-option test. Change-Id: I1669858a6e8252e167b464586e8d0b6cb0d0bd50 --- M be/src/service/query-options-test.cc M be/src/service/query-options.cc M be/src/service/query-options.h M common/thrift/ImpalaService.thrift M common/thrift/Query.thrift M fe/src/main/java/org/apache/impala/analysis/Analyzer.java M fe/src/main/java/org/apache/impala/analysis/SelectStmt.java A fe/src/main/java/org/apache/impala/rewrite/CountDistinctToNdvRule.java A fe/src/main/java/org/apache/impala/rewrite/DefaultNdvScaleRule.java M fe/src/test/java/org/apache/impala/analysis/ExprRewriteRulesTest.java M fe/src/test/java/org/apache/impala/analysis/ExprRewriterTest.java 11 files changed, 251 insertions(+), 34 deletions(-) git pull ssh://gerrit.cloudera.org:29418/Impala-ASF refs/changes/06/17306/9 -- To view, visit http://gerrit.cloudera.org:8080/17306 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-MessageType: newpatchset Gerrit-Change-Id: I1669858a6e8252e167b464586e8d0b6cb0d0bd50 Gerrit-Change-Number: 17306 Gerrit-PatchSet: 9 Gerrit-Owner: fifteencai Gerrit-Reviewer: Aman Sinha Gerrit-Reviewer: Impala Public Jenkins Gerrit-Reviewer: Qifan Chen Gerrit-Reviewer: Quanlong Huang
