What is the impact of not "closing" queries, when using the%Resultset library?

Question

Question

VICTOR GALVAO · Sep 15, 2020

Hi guys!!

In the system that I work, I came across an iterator pattern that uses the %Resultset library without performing the close after executing the query. Does anyone know how to say what are the impacts of not performing such a procedure?

If you have any model of iterator pattern made in caché to recommend as a good example, I will be grateful hehe :D

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Robert Cemper · Sep 15, 2020

If there are queries hanging around then the mayor impact is just on IRISTEMP or CACHETEMP database that might grow.
But it's not worth mentioning just for a query.

2 0

score 1 · Answer 1 · 2020-09-15T15:51:19-04:00

Typically a %ResultSet is an object. It is destroyed as soon as you de-reference it.
This could be a ba killing the referencing variable or by assigning a different value.
there is no need for a %Close or an object destructor. this happens implicitely.

set rs= ##class(%ResultSet).%New()
. . . . ; work it 
kill rs
; or 
set rs=""

score 0 · Answer 2 · 2020-09-15T16:54:14-04:00

Thanks for your help, Robert. But in the scenery when the object is not killed, and N queries are keeping open, what this can causes? An Opened query consumes memory and buffer? Wich impacts it causes on other processes? Do you know?

score 1 · Answer 3 · 2020-09-15T21:29:13-04:00

I agree with Robert. I have seldom if ever seen code that calls the ResultSet Close() method. There may be temprary globals left over in the CacheTemp database but if I am not mistaken there is a system Purge method that is run as part of the standard system tasks to clear-down these temporary structures. However if you want to complete the ResultSet functionality from Start to Finish then there is no harm in calling the Close() method.

score 0 · Answer 4 · 2020-09-15T21:29:24-04:00

I agree with Robert. I have seldom if ever seen code that calls the ResultSet Close() method. There may be temprary globals left over in the CacheTemp database but if I am not mistaken there is a system Purge method that is run as part of the standard system tasks to clear-down these temporary structures. However if you want to complete the ResultSet functionality from Start to Finish then there is no harm in calling the Close() method.