[
https://issues.apache.org/jira/browse/PHOENIX-418?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16144378#comment-16144378
]
Hadoop QA commented on PHOENIX-418:
-----------------------------------
{color:red}-1 overall{color}. Here are the results of testing the latest
attachment
http://issues.apache.org/jira/secure/attachment/12884107/PHOENIX-418-v6.patch
against master branch at commit 435441ea8ba336e1967b03cf84f1868c5ef14790.
ATTACHMENT ID: 12884107
{color:green}+1 @author{color}. The patch does not contain any @author
tags.
{color:red}-1 tests included{color}. The patch doesn't appear to include
any new or modified tests.
Please justify why no new tests are needed for this
patch.
Also please list what manual steps were performed to
verify this patch.
{color:green}+1 javac{color}. The applied patch does not increase the
total number of javac compiler warnings.
{color:red}-1 javadoc{color}. The javadoc tool appears to have generated
56 warning messages.
{color:green}+1 release audit{color}. The applied patch does not increase
the total number of release audit warnings.
{color:red}-1 lineLengths{color}. The patch introduces the following lines
longer than 100:
+ String query = "SELECT APPROX_COUNT_DISTINCT(a.i1||a.i2||b.i2)
FROM " + tableName + " a, " + tableName
+ final private void prepareTableWithValues(final Connection conn, final
int nRows) throws Exception {
+ final PreparedStatement stmt = conn.prepareStatement("upsert
into " + tableName + " VALUES (?, ?)");
+@BuiltInFunction(name=DistinctCountHyperLogLogAggregateFunction.NAME,
nodeClass=DistinctCountHyperLogLogAggregateParseNode.class, args= {@Argument()}
)
+ public DistinctCountHyperLogLogAggregateFunction(List<Expression>
childExpressions, CountAggregateFunction delegate){
+ private HyperLogLogPlus hll = new
HyperLogLogPlus(DistinctCountHyperLogLogAggregateFunction.NormalSetPrecision,
DistinctCountHyperLogLogAggregateFunction.SparseSetPrecision);
+ private HyperLogLogPlus hll = new
HyperLogLogPlus(DistinctCountHyperLogLogAggregateFunction.NormalSetPrecision,
DistinctCountHyperLogLogAggregateFunction.SparseSetPrecision);
+ protected final ImmutableBytesWritable valueByteArray = new
ImmutableBytesWritable(ByteUtil.EMPTY_BYTE_ARRAY);
+ public DistinctCountHyperLogLogAggregateParseNode(String name,
List<ParseNode> children, BuiltInFunctionInfo info) {
+ public FunctionExpression create(List<Expression> children,
StatementContext context) throws SQLException {
{color:red}-1 core tests{color}. The patch failed these unit tests:
./phoenix-core/target/failsafe-reports/TEST-org.apache.phoenix.end2end.QueryIT
Test results:
https://builds.apache.org/job/PreCommit-PHOENIX-Build/1314//testReport/
Javadoc warnings:
https://builds.apache.org/job/PreCommit-PHOENIX-Build/1314//artifact/patchprocess/patchJavadocWarnings.txt
Console output:
https://builds.apache.org/job/PreCommit-PHOENIX-Build/1314//console
This message is automatically generated.
> Support approximate COUNT DISTINCT
> ----------------------------------
>
> Key: PHOENIX-418
> URL: https://issues.apache.org/jira/browse/PHOENIX-418
> Project: Phoenix
> Issue Type: Task
> Reporter: James Taylor
> Assignee: Ethan Wang
> Labels: gsoc2016
> Attachments: PHOENIX-418-v1.patch, PHOENIX-418-v2.patch,
> PHOENIX-418-v3.patch, PHOENIX-418-v4.patch, PHOENIX-418-v5.patch,
> PHOENIX-418-v6.patch
>
>
> Support an "approximation" of count distinct to prevent having to hold on to
> all distinct values (since this will not scale well when the number of
> distinct values is huge). The Apache Drill folks have had some interesting
> discussions on this
> [here](http://mail-archives.apache.org/mod_mbox/incubator-drill-dev/201306.mbox/%3CJIRA.12650169.1369931282407.88049.1370645900553%40arcas%3E).
> They recommend using [Welford's
> method](http://en.wikipedia.org/wiki/Algorithms_for_calculating_variance_Online_algorithm).
> I'm open to having a config option that uses exact versus approximate. I
> don't have experience implementing an approximate implementation, so I'm not
> sure how much state is required to keep on the server and return to the
> client (other than realizing it'd be much less that returning all distinct
> values and their counts).
--
This message was sent by Atlassian JIRA
(v6.4.14#64029)
