Managing SQL Queries in R Lang

Question

I am having an existing calculation view which I want to delegate to a R server for its processing. However, I am getting trouble doing a select statement inside a stored procedure that is written in RLang. What I want to do after the data is coming properly is to use R functions instead of SQL for common operations like count, sum, etc on results . I've gone through SAP Hana R Integration Guide, but there is no direct way to do so. Please suggest if there is an easy way to use the columns from input parameters (and frame the results into the output parameter tables).
Edit: To make this question more relevant, I am including a sample of what I am trying to achieve:
    CREATE PROCEDURE SUMIT.DUMMY_R_PROC( 
        IN input1 SUMIT."INPUT_TABLE",
        OUT result SUMIT."SAMPLE" 
    LANGUAGE RLANG READS SQL DATA  
    AS 
    BEGIN 
        library(kernlab)
        result <- data.frame(input1)  
    END;
Note that I am simply returning the values of input1 to result. What I'd like here is to use these values  just like a calculation view - using R equivalent functions for count()/round() and calculations based on different columns.

Answer 1

Hi,
If you just want to see what sql is executed by a session you can use sql trace. This can be switched on for a whole system but is usually more usable when switched on for individual users. The problem with a system like APEX is that database sessions are not directly associated with APEX users and APEX sessions can share database sessions.
I haven't tried it, but one method that may work is to put a schema logon trigger on the APEX_PUBLIC_USER which switches on tracing when ever this user logs on to the database. It may take a little detective work to understand the sequence of things but all the SQL executed by this user will be recorded and can be analyzed for performance etc. The command to enable SQL tracing could be embedded in the APEX app, but it may be a little random as to which db session has it enabled.
Perhaps a better tracing option could be seen as a feature request in a future version of APEX.
Regards
Andre