If I have a column defined as VARCHAR(2000) and I insert a string
'WonderHowMuchSpaceThisTakes!!!' which has only 30 bytes, will Vertica consume the utilized 30 bytes or the all the allocated 2000?
Vertica stores the 30 characters efficiently on disk in the projection, but you will pay a performance penalty at run-time if varchar columns are "over-declared". The execution engine will use the full 2000 characters during query execution and will use extra storage for temp space operations.