Improving performance of Update Column in MapInfo?

Question

I have two files in MapInfo Professional:

• A mapped 'Network' file
• A non-mapped 'data' file.

They have similar data in terms of their 'link ID'

I have created a number of columns in the 'network' file which are blank. These mirror exactly the type and name of the columns in the 'data' file. I'm updating the columns of the network file e.g. 'SumObs' from the 'SumObs' in the 'data' file.

This works with the 'Update Column' tool.

However, it is painfully slow, even with FASTEDIT ON. It took overnight to complete one column, and considering I have 8 columns for 4 similar files this will take all month!

Is there a quicker way?

Answer 1

As commented by @hc91:

it was Table Maintenance - Pack Tables that helped. It is also faster with the FASTEDIT on and by not having so many 'Float' columns.

Answer 2

If you need to update multiple columns, it might be faster to first join the two tables and then update all columns in one statement.

Something along these lines:

Select Tab1.ColA "WriteColA", tab2.ColA "ReadColA", Tab1.ColB "WriteColB", tab2.ColB "ReadColB"
From Tab1, Tab2
Where Tab1.ID = Tab2.ID
Into __TO__UPDATE Noselect

Update __TO__UPDATE
   Set  WriteColA = ReadColA,
        WriteColB = ReadColB

As you can see the Update statement allows you to update multiple columns. Note that I use Column Alias in my Select statement so that I know which column to update with data from what column.