Getting error for a view ( a!queryEntity [line 4]: An error occurred while retrieving the data. Details: Memory threshold reached during output conversion)

 hi all,

We have a view for bar cart field which recently bracked in prod due heavy volume of data approx (1,048,576) records in my sql db . 

so we plan to query data going with sp with (executestoredprocedure) function. my question is can we query data in a barcart field with SP ?

while executing SP  with mandatory  parameters getting error as "Use the Execute Stored Procedure Smart Service to modify data. This function must only be used to query data, not modify."

if i pass optional parameters also getting error as "The conversion from UNKNOWN to UNKNOWN is unsupported".

Below is the code for SP, 

a!localVariables(
local!sp: fn!executestoredprocedure(
cons!DATA_SCOURCE_NAME,
cons!TASK_GRAPHIC_SUMMARY,
{
{

name:"assignedTo",
value:ri!currentUserEmail
},
{
name:"categoryName",
value:ri!categoryName
},
{
name:"lob",
value:ri!lob
},
{
name:"assignedcategory",
value:ri!assignedcategory
},
{
name:"taskId",
value:ri!taskId
},
{
name:"dueIn",
value:ri!dueIn
},
}
),
{local!sp}
)

Thanks In Advance Guys.