PACK and ZAP reindex the table anyway. You may not notice it on ZAP because RECCOUNT() is 0, however when you PACK a indexed table SET TALK ON and you'll be able to see the reindex count.

Sorin

>>A CDX is always open when its table is in use. I noticed that a reindex can speed a little the app when the table is big and it was very much modified.
>>
>But it's not essential at any time, even for Pack/Zap? Maybe just occasional maintenance reindexing on large busy tables will do?