Excel Performance - INDEX-MATCH combination - excel

Question

I am using excel to create data sets that are used in a vba application later. I am using this formula:
=INDEX(BaseData!$L$2:$L$10000;MATCH(DataSet!D5&DataSet!E5&DataSet!K5;INDEX(B‌​aseData!$B$2:$B$10000&BaseData!$C$2:$C$10000&BaseData!$D$2:$D$10000;0);0))
usually with a range from f.ex.: A2 - A10000, because my data can be differently long and often vary in data selection.
However, this slows my excel extremely down. I switched to manual calculations, but then, when activating automatic again, my excel instance takes extremely long and often crashes.
I also tried to past some data, but when creating a new dataset, I have to pull the formula down again and sometimes through this errors occur in my data set.
Any suggestions what I can do to make the INDEX-MATCH formulas more performant?
I appreciate your replies!
UPDATE
I guess a lot of performance goes away because index-match does not select the exact range, but also counts in blank rows. How to get the exactl range with index match automatically?

Answer 1

As I mention in my comment above, as long as this is a 'regular' formula and not an Array Formula, you may find success simply replacing "A1:A10000" with "A:A". However barring that, you can create a cell which will calculate reference the number of rows of data which you have, and then use that cell to indirectly reference the complete column with data in it.
CALCULATING YOUR DESIRED RANGE
For the following example to work, I assume that: Column A includes an index key in the form of numbers only; Column A includes no numbers in the header and above; and that the index rows are continuous, with no breaks. Start with the following formula:
=COUNT(A:A)
If my assumptions above hold, then this will return the number of data elements in your table. Once we know where this data starts, we can use this COUNT to determine where it ends. Assume your header is in row 2. (I like to include the header so that if you insert a row beneath the header, Excel picks up that you want to include the new row in your formulas).With that in mind, this formula will create the Excel-style reference which finds the last cell in column A which has data in it:
=ADDRESS(ROW(A2)+1+COUNT(A:A),COLUMN(A2),1,1)
Assuming 50 rows of data [which start at row 3, below the header], and all other assumptions above, this formula will return the text result "$A$53".
If you wanted to do the same thing, but instead return the full range in Column A where data exists (from the header to row 53), you could do as follows:
=ADDRESS(ROW(A2),COLUMN(A2),1,1)&":"&ADDRESS(ROW(A2)+1+COUNT(A:A),COLUMN(A2),1,1)
This returns the text string result "$A$2:$A$53", which is a reference to the full index of unique ID values. It will automatically move around as you would generally expect if you insert any rows or columns. Now assume for your INDEX that you want to pull the same data, but for column B, instead. The formula will be exactly the same, except that where I have "COLUMN(A2)" above, replace with "COLUMN(B2)".
REFERENCING YOUR CALCULATED RANGE
So now you have the address of your proper, limited columns - but how do you actually reference those areas in a formula? By using the INDIRECT function. INDIRECT says "Evaluate some specific criteria. It will create a cell reference. Now look at that cell reference." In its simplest form, this could look like this:
=INDIRECT(A1)
Assume that A1 holds the value "B5". Indirect will pick up the value "B5", and instead of displaying "B5", it will go to B5, and pick up the value there. So to use this with the above, wrap the whole thing in the INDIRECT function. Instead of picking up the text string "$A$1:$A$53", it will actually now reference that range properly. Like so:
=INDIRECT(ADDRESS(ROW(A2),COLUMN(A2),1,1)&":"&ADDRESS(ROW(A2)+1+COUNT(A:A),COLUMN(A2),1,1))
USING A NAMED RANGE
But that is a very long formula to have, and you won't want to use it within a specific cell for a simple INDEX/MATCH. Instead of entering these formulas in cells (although you could), I recommend you go to the Formula Ribbon -> Name Manager -> New Name. Call the name for the index of A "ID_COLUMN". Call the name for the index of "B_COLUMN" (or something more specific).
FINAL FORMULA
Now, if you wanted to make an INDEX/MATCH of your table, which automatically grows/shrinks as you change the data, your formula would look like this [this would, for example, pick the row from column B where column A has the number 100]:
=INDEX(ID_COLUMN,MATCH(100, B_COLUMN, 0))