I personally like the functional indexes. I think they are useful for all cases where querries have expressions in predicates.
Satheesh Jeremy Boynes wrote: > This is a subject that keeps coming up on the mailing lists so is > probably worth addressing. > > One challenge we face is that many users are likely to be considering > Derby as an alternative to MySQL which by default uses a > case-insensitive collation. This is legal SQL, just different from > most other databases (Oracle, DB2, SQL Server (which actually allows > you to choose when you create the database)). > > The standard way of solving this would be to support user-specified > character sets and collations per the spec but > 1) that's likely to be a lot of work > 2) I don't know of another database that actually does this the way > the spec says, making us "different", and > 3) it is likely to be more confusing than helpful > > Other options include: > a) support collation specification at the schema level like SQL Server > b) support function-based indexes, so users can create indexes > on UPPER(col) to reduce the performance hit > c) just document and offer workarounds (like adding a second column) > d) change Derby to be like MySQL (gets a -1 from me but ...) > > Thoughts? > -- > Jeremy > > >
