That will only work when the address fields are exactly alike. If this is the case why not something like

Update File1 set Matched = .t. where File1Address in (Select File2Address from File2)

>I can do this via a scan and lookup, but I think I remember 15 years ago I used to do it with a relationship and it was much faster. Can someone refresh my memory on the technique?
>
>There are 2 tables each with an address column. Table 1 also has a logical field defaulted to false. I want to set this field to true if the address in table1 also exists in table 2. How do you set up the relationship and then mark the matching records true?
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>Thanks