Hi Anton,
1) according to org.apache.calcite.sql.fun.SqlAvgAggFunction " the
result is the same type" so I think this is standard SQL behavior.
2) This seems to be a code generation bug. The sqrt/power function seems
not accept the data types. Would be great if you could open an issue if
it does not yet exists in Jira.
I hope that helps.
Regards,
Timo
Am 04/10/16 um 18:04 schrieb Anton Mushin:
Hello all,
I have some questions about work with FlinkSQL.
1) I'm want calculate average for column values:
val env = ExecutionEnvironment.getExecutionEnvironment
val tEnv = TableEnvironment.getTableEnvironment(env, config)
val ds = env.fromElements(
(1.0f, 1),
(2.0f, 2)).toTable(tEnv)
tEnv.registerTable("MyTable", ds)
val sqlQuery="select avg(_1), avg(_2) from MyTable"
tEnv.sql(sqlQuery).toDataSet[Row].collect().foreach(x=>print(s"$x "))
As result I'm getting: "1.5,1 ". But I expected: "1.5,1.5 "
Why is for columns like integer types avg function is return result as integer?
Where is described this behavior?
2) I wanted calculate stddev_pop function like as sequences sql aggregate
functions, how it is describe in calcite javadocs:
https://github.com/apache/calcite/blob/master/core/src/main/java/org/apache/calcite/rel/rules/AggregateReduceFunctionsRule.java#L64
val ds = env.fromElements(
(1.0f, 1),
(1.0f, 2)).toTable(tEnv)
tEnv.registerTable("MyTable", ds)
val sqlQuery = "SELECT " +
"SQRT((SUM(a*a) - SUM(a)*SUM(a)/COUNT(a))/COUNT(a)) "+
"from (select _1 as a from MyTable)"
tEnv.sql(sqlQuery).toDataSet[Row].collect().foreach(print)
I got exception:
org.apache.flink.runtime.client.JobExecutionException: Job execution
failed.
.......
Caused by: java.lang.Exception: The user defined 'open(Configuration)'
method in class org.apache.flink.api.table.runtime.FlatMapRunner caused an
exception: Table program cannot be compiled. This is a bug. Please file an
issue.
at
org.apache.flink.runtime.operators.BatchTask.openUserCode(BatchTask.java:1337)
at
org.apache.flink.runtime.operators.chaining.ChainedFlatMapDriver.openTask(ChainedFlatMapDriver.java:47)
.....
Caused by: org.codehaus.commons.compiler.CompileException: Line 59, Column 57: No applicable constructor/method
found for actual parameters "float, java.math.BigDecimal"; candidates are: "public static double
org.apache.calcite.runtime.SqlFunctions.power(long, java.math.BigDecimal)", "public static double
org.apache.calcite.runtime.SqlFunctions.power(long, long)", "public static double
org.apache.calcite.runtime.SqlFunctions.power(double, double)"
at
org.codehaus.janino.UnitCompiler.compileError(UnitCompiler.java:10062)
at
org.codehaus.janino.UnitCompiler.findMostSpecificIInvocable(UnitCompiler.java:7476)
In this time if I am execute for int column ('_2') i getting result is equals
'0.0'
What am I doing wrong?
Best regards,
Anton Mushin
--
Freundliche Grüße / Kind Regards
Timo Walther
Follow me: @twalthr
https://www.linkedin.com/in/twalthr
