The various SQL product vendors implement subtle differences in the way they interpret SQL. In this case, I've been examining the reuse of constraint names within a schema / database (which is yet another story: what's a schema, what's a database?). Here's the summary: Constraint names are unique within a schema Derby H2 HSQLDB Ingres … Continue reading Subtle SQL differences: Constraint names
Tag: foreign key
How schema meta data impacts Oracle query transformations
I was recently wondering about some issue I had encountered between two tables. If tables undergo a lot of INSERT / UPDATE / DELETE statements, it may appear to be better to remove some constraints, at least temporarily for the loading of data. In this particular case, the foreign key relationship was permanently absent and … Continue reading How schema meta data impacts Oracle query transformations