Jim,

I Tested the DELETED() tag behaviour for FPW 2.6 in the following circumstances.

- On a NT-server machine, No other Fox versions installed.
- Over a 10 mb lan network (not used by other means than this experiment).
- With a SQL SELECT SUM() FROM ... WHERE Expression (Expression is rushmore optimizable)
- With a SQL SELECT *, .T. FROM ... WHERE Expression (Expression is rushmore optimizable)
- I used two identical tables: one with the index on deleted() (TAGGED) the other not (NONTAGGED).
- The tables were not fragmented, the indexes balanced with reindex.
- The tables both are approx 17MB, 152.000 records.
- I did test the performance with 5%, 10% and 20% deleted records.

When the queries run for the first time the difference between performance between the deleted()
tagged and the non tagged table where as follows: The TAGGED table was a little slower when the amount of records dropped below the 10%
and was a bit faster when the amount of records was above the 10%. This may sound reasonable because the extra deleted() tag is dragged over the network while it's benefit is virtually none when there are just a few deleted records.

For the record: All the queries run in approx 11 seconds and the variation was about a few tenths of a second.


When the index was alread on the client, the TAGGED queries run almost alway's according the following formula.
- Perforance gain in seconds = Totaltime NONTAGGED query * deleterecords% * OverheadUsingDeletedTag(approx .60)

Though I know that this won't prove anything about the deleted() tag in all cirumstances, but It gives me the impression that not muchs
has changed since the FP(W) 2.x days

Walter,