Let me first say I've been through lots of CMS, DMS, and a few Wiki's and Outliners. The closest three programs I've found that resembles the kind of product I'm looking for are: Tiki Wiki (too many plugins, broken features, too many config options, and lacking several of the config options I was looking for (++)) Treepad (Lacking several of the features mentioned below), and Processwire (The features I'm looking for required plugins that happen to break PW upon install or slightly after. Was too much of a hassle to install the necessary plugins that didn't really feature everything I needed anyway + some which broke PW itself (++))
I'm looking for software that can store, link and organize a near unlimited amount of tabular data and notes inside a tree structure/hierarchy. These features should be core features, not plugins (for the sake of maintainability). And it would be nice to be able to retrieve this data programmatically with relative ease, and this one optional feature can be a plugin.
Example of navigation: My Database (Container) -> Tables (Container) -> Food (Table) -> Stores => Sweden,Göteborg,Coop-Obs (Filter)
Explanation: In this example there are 3 data types: Container, Table, Filter. A container can be followed up by any data type. A table can only be followed up by a Filter or a Linked (Sub-)Table. A filter can only be followed up by more filters (or no follow-up). Sweden is a country, Göteborg is a city in Sweden, and Coop Obs is a store in Göteborg. Also the "filter" data-type demonstrated above is not a necessary feature, but it should be possible to include/exclude data based on the values of a given column/field.
I don't know how the actual data would be structured, but based on the navigation values the data displayed would be all data that satisfies the condition of being from the location Sweden->Göteborg->Coop-Obs.
As for what kind of data the table 'Food' should contain: At least food products, ingredients (which should further be possible to look up individually), at what locations these food products can be bought (can also be looked up further), the price of the product at this location, and when the products availability was last confirmed at the given location. If necessary this data can be split into sub-tables (food-ingredients and food-locations), but it's critical that setting up new tables and sub-tables should be fairly simple.