At 01:47 PM 1/5/2009, Tom Frederick wrote:
Today, I had two LAN based tables pop up the error message 'Cannot read table structure' while running Relational Verification before using Design. Other LAN tables had no problems with RV or Design. A clone development database on another drive works just fine. Using 12/29 V8 and did the usual checks including reload. RV has been ON for several months for no particular reason. When RV is turned off, the tables popped up immediately and operate / save like always.
Tom, FWIW, one should never make any structural changes on a "live" database on the network. Depending on the number of columns and total rows, due to the Concurrency control, Table LOCKs and VERIFY settings, you may observe a delay when performing structural changes.
My understanding is RV ON checks table structures before changes and RV OFF checks table structures after saving any changes. Is there a reason to leave RV ON if OFF seems to work just fine? If these messages are a sign of something developing, what is a likely solution? I am putting an Audit system into the Forms for these tables, but have not changed the tables themselves in a long time.
Technically, while in Table Designer (RBDefine), every key pressed to change the existing column name or data type, or to simply add a new column, the R:BASE Engine behind the scenes performs an instant check for "Relational Integrity" to verify the column and data type. In case of a discrepancy it prepares the -ERROR- message(s) to be displayed. The -ERROR- must be resolved before the next step is taken. This is a great feature to avoid stupid mistakes. However, it can take a little longer if you have hundreds of tables with thousands of different columns to check every time you press the [Enter] key. The alternate option is to keep typing away and check the data relational integrity only when pressing the [Save] button. Keeping that feature in mind, now it's up to the developer to make a wise choice. You have the option of setting the "Relational Verification" to ON (Checked) or OFF (unchecked). The default is set to OFF. We have provided you the tools and options, it's up to you as a developer to use it wisely. Enjoy! Very Best R:egards, Razzak.
