Hi!

When I create an Index with 2 collumns as key-values, what kind of index does db2 create?

example:
table schema is tab1{[a: integer, b: char(10)]}

index creation:

create index index1 on tab1 (a asc, b asc);

i don't use any clustering indexes, and

select indextype from syscat.indexes where indname='index1'

gives me "REG", so it's not a dimensional block index.

Therefore it must be a kind of B+ -tree, but how are 2 keys organized in a B+-Tree? are they somehow merged to one keyvalue?

Types of index access
seems to imply that one level of the b+-tree filled with key a -values and the next level with key b-values, but I couldn't find a clear statement on this.

a link pointing to an answer would be nice. thanks in advance.

Index key is a concatenation of values that make it up. Check the PDF Performance Guide for more details.