Access 2016中的查询运行时

Question

I have two very large files of which both field 1's have similar data. Now I want to use a query to compare these two files and output all rows of a particular column (Field3) in which file1.field1==file2.field1. This can of course be done with a simple query. I can not use join since there is too much text in the fields, so I use WHERE but this apparantly slows down the query by a lot.

Query:

SELECT Category_list.Field3
FROM Category_list, Uri_list
WHERE (Category_list.Field1=Uri_list.Field1);

Now this query is running, but I have no idea how long it will take. It could be a few hours but it wouldn't surprise me if it takes days. Is it possible to see in access how far into the query it is, so that I can get at least an idea of what the runtime will be?

Category_list has about 2.8 million rows and Uri_list has about 4 million rows. If needed I could lower the Uri_list to about 100.000 rows minimum, but that depends on the runtime..

Thanks in advance for the help :)

Answer 1

My suggestion:

• Import both files into Access as local tables, using the text import assistant
• Create an index in both tables on Field1. If the values are unique, an unique index or even better a PrimaryKey; if not, a non-unique index.
• Create a simple query with JOIN

This should run fast enough.

Is it possible to see in access how far into the query it is, so that I can get at least an idea of what the runtime will be?

Sometimes (especially for Update queries), Access shows a progress bar. But if not, no - there is no way to see the progress.