Hi, I’m currently trying to optimize indexes for a Tamino 4.2 database. I want to introduce some compount indexes in order to replace some indexes based on single fields.
Lets say, I have a docType where documents are identified by @class and @key (in the root tag) and all filters use @class and some additionally @key.
Currently there will be two individual indexes on @class and @key, but it seems to make sense to use a compound index here (maybe even with unique constraint).
I’ve tried this and hoped that ino:explain for my XPath expression would differ significently, but I don’t see much. On default level I see that preselection is true with both schema definition. On the more detailled levels this remains and I currently have no clue how to interpret the output for compound indexes (the docs only cover a single component index), because it almost looks the same as with the old index definitions…
Apart from this the xop:preselectable values are not clear to me. They are always false in my tests… :shock:
What’s the criteria for them to switch to true? Should I bother about “true” values here at all?
Thanks in advance