Tags: VLOOKUP

Speeding up a lookup task on a large database

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Performing calculations or writing formulas on large databases pose the following major problems:

1. Time taken to process is unduly long; and
2. File size increases disproportionately

A typical problem is fetching data from another worksheet or workbook via the VLOOKUP() function.  Quite often, when one confirms the VLOOKUP() formula in a single cell with the Enter key, then at the bottom right of your MS Excel screen (the task bar), a white progress bar appears which reads "Calculating (4 processors) 1%".  Once has to wait for the processing to complete before copying the formula down.  The process of copying is obviously just as time consuming and resource intensive.

In these situations, a workaround is the JOIN the tables in MS Access and then get the data back in MS Excel.  For accomplishing this, one must have at least some working knowledge of "SQL Query" writing.

If you are using the Power Query add-in for MS Excel 2010 and higher versions, then one can fetch data from another worksheet or workbook without writing a single formula.  Furthermore, there is absolutely no lag in generating the result.

You may refer to my Power Query solution in this workbook (This is a 20 MB file)

Create a Pivot Table from multiple individual ranges without using ancillary columns

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Assume that there are three separate tables showing the following information:

1. Date of visit data for visitors to a certain recreation facility.  The same visitor may visit the facility multiple times
2. Fee per visit in different cites
3. Region in which each city lies

The question is to analyse the three tables above via a Pivot Table to generate the following:

1. Region wise and visitor wise:
a.  Fee per visit
b.  Frequency of visit
c.  Revenue
2. Revenue collected by month wise and by visitor

In this workbook, I have shared two solutions:

1. PowerPivot solution - This solution answers both questions above without using any calculated/ancillary columns in the base data.  By establishing simple relationships in the PowerPivot window and by writing two calculated Field formulas, both questions above have been answered.  To use this PowerPivot solution, you need to be using the PowerPivot add-in for MS Excel.  This add-in is only available for Excel 2010 and higher versions.

2. Pivot Table solution - This solution answers both questions above by using calculated/ancillary columns in the base data.

Here's another example.  Assume a four column table showing Date of session, Client, Location and Participant Name.  Assume another four column table showing Client, Date of session, Date of invoice and Amount Billed.  The task is to determine the Amount billed per location.  You may refer to my PowerPivot and Pivot Table solution in this workbook.

Summarise data from multiple worksheets

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Assume multiple worksheets in a workbook (all having the same structure).  In a summary sheet, one may want to tabulate data from these multiple worksheets.  Essentially, a way to link to the same specific cells in multiple worksheets to the Summary sheet.  The formula in the Summary sheet should just be copied and pasted to multiple rows to bring over data from the multiple worksheets.

You may refer to my solution in this workbook.