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https://issues.apache.org/jira/browse/CALCITE-5912?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17756324#comment-17756324
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LakeShen commented on CALCITE-5912:
-----------------------------------
Sorry,I'm not very familiar with this part,I'm a little new to implementing
EnumerableSample implement method. When I write code like I did above, I get a
lot of errors when testing, but I don't really understand it.
Could someone give me some help, such as which Enumerable class implementation
to I could refer to or which method to I could use,thanks.
> Add an implementation of TABLESAMPLE in Enumerable convention
> -------------------------------------------------------------
>
> Key: CALCITE-5912
> URL: https://issues.apache.org/jira/browse/CALCITE-5912
> Project: Calcite
> Issue Type: New Feature
> Reporter: LakeShen
> Assignee: LakeShen
> Priority: Major
>
> In Calcite, the TableSample SQL statement will be converted to Sample RelNode
> plan tree,for example:
> {code:java}
> select * from emp tablesample bernoulli(10){code}
> The plan is :
> {code:java}
> LogicalProject(EMPNO=[$0], ENAME=[$1], JOB=[$2], MGR=[$3], HIREDATE=[$4],
> SAL=[$5], COMM=[$6], DEPTNO=[$7], SLACKER=[$8])
> Sample(mode=[bernoulli], rate=[10.0], repeatableSeed=[-])
> LogicalTableScan(table=[[CATALOG, SALES, EMP]]) {code}
> Currently in enumerable mode, we don't have EnumerableSample, So we can't add
> TableSample quidem tests (such as in misc.iq).
> After this jira,we could add the quidem test for TableSample(such as
> tablesample.iq),although TableSample's results are inconclusive when the 0 <
> sample rate < 100, but TampeSample(0) is certain result.
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