Hi,

On 12 Dec 2015, at 23:25, Chenxi Li wrote: Could you tell me which files have the code for primitives and operators? Thanks a lot.

You can start with the EXPLAIN output for a query, for example EXPLAIN SELECT * FROM TABLES; You will see the MAL plan for this query, which contains for example the line | C_191 := algebra.subselect(X_14,C_5,2,2,true,true,true); | This points to a MAL function, which is defined in the file algebra.mal, in particular the line command subselect(b:bat[:oid,:any_1], s:bat[:oid,:oid], low:any_1, high:any_1, li:bit, hi:bit, anti:bit) :bat[:oid,:oid] address ALGsubselect2 … address points to a C symbol, which is the function ALGsubselect2() in algebra.c The same concept holds true for most functions in the MAL plan, they are defined in .mal files and point to C functions. Hope this helps, Hannes