>Hi Jos
>
>I modified your program and ran it with the source table open and when it was closed. In Both cases, aliases B and C were present for tmp files. After the select finished running, I tried to open those files but got an error message( file is in use) which could mean that these could have been cursor created by VFP to process and swap data and not neccessarily indicative or supporting the claim that Select SQL opens its own table since they were still open.

Hi Bob,

Not sure about why you say this? When you run my code with the source table already open my program clearly shows that a second table, alias B, is opened and that its complete path is to the original source table. Hence SELECT is definitely opening a second copy. When the query finishes the table opened as alias B is no longer open.

One could enhance this little program to show that for each record being processed in alias B the source record pointer does not change - if you wanted to prove the record pointer issue. But this is in my mind pointless since why would VFP open a second copy of the file if not to use it?