vertica에서 함수 만들기

Question

많은 소스를 통해 확인했지만 결과는 얻을 수 없습니다.

어떻게 데이터베이스에 모든 세션의 수를 반환하는 Vertica의에서 함수를 만드는 방법?

누군가이 주제에서 가능한 아이디어 또는 가능한 예를 제공 할 수 있습니까?

Answer 1

가 C를 생성 ++ (count_it.cpp)

#include "Vertica.h" 
#include <time.h> 
#include <sstream> 
#include <iostream> 

using namespace Vertica; 
using namespace std; 

class Average : public AggregateFunction 
{ 
    virtual void initAggregate(ServerInterface &srvInterface, IntermediateAggs &aggs) 
    { 
     try { 
      VNumeric &sum = aggs.getNumericRef(0); 
      sum.setZero(); 

      vint &cnt = aggs.getIntRef(1); 
      cnt = 0; 
     } catch(exception& e) { 
      vt_report_error(0, "Exception while initializing intermediate aggregates: [%s]", e.what()); 
     } 
    } 

    void aggregate(ServerInterface &srvInterface, BlockReader &argReader, IntermediateAggs &aggs) 
    { 
     try { 
      VNumeric &sum = aggs.getNumericRef(0); 
      vint  &cnt = aggs.getIntRef(1); 

      do { 
       const VNumeric &input = argReader.getNumericRef(0); 
       if (!input.isNull()) { 
        sum.accumulate(&input); 
        sum.setZero(); 
        cnt++; 
       } 
      } while (argReader.next()); 
     } catch(exception& e) { 
      vt_report_error(0, "Exception while processing aggregate: [%s]", e.what()); 
     } 
    } 

    virtual void combine(ServerInterface &srvInterface,IntermediateAggs &aggs,MultipleIntermediateAggs &aggsOther) 
    { 
     try { 
      VNumeric  &mySum  = aggs.getNumericRef(0); 
      vint   &myCount = aggs.getIntRef(1); 

      do { 
       const VNumeric &otherSum = aggsOther.getNumericRef(0); 
       const vint  &otherCount = aggsOther.getIntRef(1); 

       mySum.accumulate(&otherSum); 
       mySum.setZero(); 
       myCount += otherCount; 

      } while (aggsOther.next()); 
     } catch(exception& e) { 
      vt_report_error(0, "Exception while combining intermediate aggregates: [%s]", e.what()); 
     } 
    } 

    virtual void terminate(ServerInterface &srvInterface, BlockWriter &resWriter, IntermediateAggs &aggs) 
    { 
     try { 
      const VerticaType &numtype = aggs.getTypeMetaData().getColumnType(0); 
      const VNumeric  &sum  = aggs.getNumericRef(0); 
      sum.setZero(); 

      uint64* tmp = (uint64*)malloc(numtype.getMaxSize()/sizeof(uint64)); 
      VNumeric cnt(tmp, numtype.getNumericPrecision(), numtype.getNumericScale()); 
      cnt.copy(aggs.getIntRef(1)); 
      VNumeric &out = resWriter.getNumericRef(); 
      if (cnt.isZero()) 
       out.setZero(); 
      else 
       out.add(&cnt,&sum); 
     } catch(exception& e) { 
      vt_report_error(0, "Exception while computing aggregate output: [%s]", e.what()); 
     } 
    } 

    InlineAggregate() 
}; 


class count_itFactory : public AggregateFunctionFactory 
{ 
    virtual void getPrototype(ServerInterface &srvfloaterface,ColumnTypes &argTypes,ColumnTypes &returnType) 
    { 
     argTypes.addNumeric(); 
     returnType.addNumeric(); 
    } 

    virtual void getReturnType(ServerInterface &srvfloaterface,const SizedColumnTypes &inputTypes,SizedColumnTypes &outputTypes) 
    { 
     int int_part = inputTypes.getColumnType(0).getNumericPrecision(); 
     int frac_part = inputTypes.getColumnType(0).getNumericScale(); 
     outputTypes.addNumeric(int_part+frac_part, frac_part); 
    } 

    virtual void getIntermediateTypes(ServerInterface &srvInterface,const SizedColumnTypes &inputTypes,SizedColumnTypes &intermediateTypeMetaData) 
    { 
     int int_part = inputTypes.getColumnType(0).getNumericIntegral(); 
     int frac_part = inputTypes.getColumnType(0).getNumericFractional(); 
     intermediateTypeMetaData.addNumeric(int_part+frac_part, frac_part); 
     intermediateTypeMetaData.addInt(); 
    } 

    virtual AggregateFunction *createAggregateFunction(ServerInterface &srvfloaterface) 
    { return vt_createFuncObject<Average>(srvfloaterface.allocator); } 

}; 

RegisterFactory(count_itFactory); 

컴파일 C++

,

라이브러리

CREATE LIBRARY count_it AS '/home/dbadmin/libs/count_it.so'; 

생성 기능을

CREATE AGGREGATE FUNCTION count_it AS LANGUAGE 'C++' NAME 'count_itFactory' LIBRARY count_it; 

사용 함수를 생성

0

select count_it(client_id) from sesions; 

Answer 2

Vertica에서 UDX를 만들 수 있지만 세션 핸들이 없으므로 API를 통해 노출 된 데이터에만 액세스 할 수 있습니다. 세션 데이터가 공개되지 않습니다.

이렇게하려면 쿼리를 실행해야합니다.

SELECT COUNT(*) FROM sessions; 

Answer 3

유사한이 게시물을 참조 :

v_monitor.sessions FROM

SELECT 
node_name 
,user_name 
,'SELECT CLOSE_SESSION(''' || session_id || ''');' AS CloseSession 
,statement_start 
,(GETDATE() - statement_start)::INTERVAL AS current_statement_duration 
,REGEXP_REPLACE(current_statement,'[rnt]',' ') AS current_statement 
,session_id 
,transaction_id 
,statement_id 
,client_hostname 
,client_os 
,login_timestamp 
,runtime_priority 
,ssl_state 
,authentication_method 
,transaction_start 
,GETDATE() AS Today 

current_statement_duration의 DESC BY ORDER;

또한 당신은이 게시물에서 더 많은 정보를 얻을 수 있습니다 Script to List Vertica Active Sessions