Excel calculation process / INDIRECT in an array formula - excel

Question

I got this spreadsheet where on daily basis I will be pasting data ranging from hundreds to thousands of rows. And this spreadsheet is heavy loaded with functions. I would like to cut calculation time as much as possible but not quite sure how excel is designed to process data. Is there a difference between two functions which are ranging like these:
SUM(A2:A50) and SUM(A2:A99999)
How I look at this: SUM function on first example will stop running once it reaches A50 cell and on second example it will keep running until it reaches A99999. From this I can say first is more efficient to have in your spreadsheet.
Please advice.
I got this formula which returns me an #N/A value and I believe this is because INDIRECT is included in array formula (Ctrl + Shift + Enter).
Whole formula itself:
=SUM(IF((INDIRECT("'" & $K$6 & "'!" & $K$7)>CODES!$K$2)+(MMULT(--('Data paste'!AD2:AF5>CODES!$K$1),{1;1;1})>0)+(MMULT(--('Data paste'!AD2:AF5>CODES!$K$3),{1;1;1})>1)+--('Data paste'!AD2:AD5*'Data paste'!AE2:AE5*'Data paste'!AF2:AF5>CODES!$K$4), 1, 0)*--('Data paste'!Q2:Q5=CODES!C2))
Please find a spreadsheet uploaded onto the GDrive so it is easier for you to understand what do I mean. Formula is located on CODES sheet E2 cell.
Thank you.

Answer 1

Obviously, referencing smaller ranges will always be faster or at least equally fast. However, Excel does have some optimization:
Many Excel built-in functions (SUM, SUMIF) calculate whole column references efficiently because they automatically recognize the last used row in the column. However, array calculation functions like SUMPRODUCT either cannot handle whole column references or calculate all the cells in the column.
so that shouldn't be terribly important for SUM(A2:A99999).
As for question number 2: Yes, you may use INDIRECT() within an array formula. It just currently returns NA because you're trying to add two arrays of different length:
{FALSE; TRUE} + {FALSE; FALSE; FALSE; FALSE} = {0; 1; #NA; #NA}
How to fix your issue:
change CODES!K7 to
=COUNTA('Data paste'!A:A)
and change CODES!E2 to
=SUM(IF(('Data paste'!AA2:INDEX('Data paste'!AA:AA,$K$7)>CODES!$K$2)
+(MMULT(--('Data paste'!AD2:INDEX('Data paste'!AF:AF,$K$7)>CODES!$K$1),{1;1;1})>0)
+(MMULT(--('Data paste'!AD2:INDEX('Data paste'!AF:AF,$K$7)>CODES!$K$3),{1;1;1})>1)
+--('Data paste'!AD2:INDEX('Data paste'!AD:AD,$K$7)*'Data paste'!AE2:INDEX('Data paste'!AE:AE,$K$7)*'Data paste'!AF2:INDEX('Data paste'!AF:AF,$K$7)>CODES!$K$4), 1, 0)
*--('Data paste'!Q2:INDEX('Data paste'!Q:Q,$K$7)=CODES!C2))
I have replaced Indirect() calls by Index(), which should benefit performance.