Hi Ed,

>Bill, you've hit on one of those much-neglected performance issues with VFP native files that're near and dear to my heart - file bloat and data localization. Rebuilding CDX files from scratch on a regular basis, and completely rebuilding data files (especially ones with memo and general fields) so that the files are physically sequenced in a natural order with no 'holes' left from deletion or updating memo/general content is a very simple and effective performance optimizing trick. Coupled with defragmentation of the disk drive, it minimizes the cost of file access - FAT partitions in particular have a relatively heavy penalty for backwards movement within a file, and the cost of forward sequential reads is highest when physical disk head motion is minimized.

The first time I ran into this was shortly after upgrading to VFP5. (I only started using Fox just before VFP3 came out) I had just redesigned our data access to use parameterized views instead of using the table and seeking, in anticiaption of using SQL Server. The performance was horrible! We almost scrapped the idea. I added/deleted tags etc. Finally, I dropped all the tags (and relations) and recreated them from scratch. BANG! It flew! Now a rebuild option is available as a utility for our application.

>>and the cost of forward sequential reads is highest when physical disk head motion is minimized.
Huh? You did mean LOWEST, right? Or am I really confused?

Bill