Recompilation required if table dropped and added again?

[Joel W Winston]

Dear ALL,

Would a recompilation be required if a table is dropped and added again in OE 10.2B database.

When I add it again I would maintain the field order etc.

Could someone clarify this?

Thanks
Joel

 

[Cringer]

I'd have thought yes, but I have no evidence either way.

 

[Joel W Winston]

An Update

Just now I made a test against the sports DB and found that the code does not require a recompile.

Thanks
Joel

 

[Cringer]

Ah thanks for the update

 

[RealHeavyDude]

Maybe this article sheds more light on the question:

http://knowledgebase.progress.com/articles/Article/P167155

As far as I read the article that is expected behavior - if you delete a table and immediately add it again you don't need to re-compile. An interesting test would be if the same is true when you add some other tables before you re-add the deleted table so that it might get a different table number.

Heavy Regards, RealHeavyDude.

 

[Stefan]

Maybe this article sheds more light on the question:


As far as I read the article that is expected behavior - if you delete a table and immediately add it again you don't need to re-compile. An interesting test would be if the same is true when you add some other tables before you re-add the deleted table so that it might get a different table number.

I am very sure that the table number etc are not part of the CRC calculation. CRC is there to ensure you are not running rcode against a different table definition. If the table is the first, the second or the last has no relevance. The table number is not part of a df, the field position (actually the r-position) is - that's why you have the option to include this when dumping a df to ensure you get a CRC-compatible table when recreating the table elsewhere. Note that you only need r-position if you are deleting fields.

initial field A B C would get r-position 1 2 3 (or something similar)
delete field B and your updated database has A C with r-position 1 3.
If you were to create a new database based on the updated database (without r-position) you would end up with A C with r-position 1 2 which has a different CRC.