I know MonetDB is a self indexing databases but how does this actually work?. I would like to learn more about how this works internally. Does MonetDB create compound indexes as well or is it just per column? What indexing strategy is being used? I was going through this document: https://www.monetdb.org/book/export/html/26 but didn't find much about this topic.
Hash indices are created automatically when the corresponding relational primitives would benefit. They are retained and maintained.
For the secondary indices see: Lefteris Sidirourgos, Martin L. Kersten: Column imprints: a secondary index structure. SIGMOD Conference 2013: 893-904 regards, Martin