UnQLite Users Forum

Is JSON Object Search with "db_fetch_all" always linear ?

append delete Mohamed Chit

As far as I understood. It is possible to perform queries using db_fetch_all () and a filter callback function.
The question is, is this always linear search ? UnQLite has to call the user defined filter callback function for each JSON object or there is some optimisation behind the scenes.

For instance MongoDB allows developers to index a collection. I do not see this option in UnQLite. Does it mean there is some optimisation hidden or it is always a linear search O( n ).

If not O( n ), what does UnQLite to speed up the query ?

Best regards

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append delete #1. devel

db_fetch_all() rely on the cursor interfaces: https://unqlite.org/c_api/unqlite_kv_cursor.html which retrieve all the records associated with the given collection and apply a filter callback if any.
Retrieving the data associated with your keys is **O(1)** if the built-in storage engine is used.

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