>>No, as long as index is open before APPEND it is updated.
>
>Then what is the speed gain?

There can be a substantial speed gain if you put dbf and cdx on different physical disks.
If you have an index used 95% of all searches and go the non-structural road IAC, switching that special index into a non-compound idx can also give an added speed boost of 10-35%.

>>>It will be used for Optimization (I am not sure about if nonstructural compound index could be used for this, because I never used them).
>>They are, but the chance of leaving one closed while adding records is too dangerous for my liking.
>Agree!

Agree mostly: ***IF*** the app is only using it's own opening functions/methods making sure the correct indices are available is definately possible. You could add more "security" via dbc-events or on app start reindex once - depends on the gains you see. Once I *HAD* sizable gains, so I implemented it. Triple-checked the code, but it was clearly faster.

regards

thomas