Eleytherios Stamatogiannakis wrote > Our main test case is TPCH, a standard DB benchmark. The "lineitem" > table of TPCH contains 16 columns, which for 10M rows would require 160M > xColumn callbacks, to pass it through the virtual table API. These > callbacks are very expensive, especially when at the other end sits a VM > (CPython or PyPy) handling them.
Would it be very difficult to arrange for an option that would request that SQLite issue a single more-complex xMultiColumns (a sample name) callback request, with a way for multiple results to be returned, rather than many xColumn callbacks? This would reduce the number of calls across the VM boundary. Applications that don't implement xMultiColumns (and request its use) would see no change; those that do would get the performance boost. J. Merrill -- View this message in context: http://sqlite.1065341.n5.nabble.com/Why-does-type-affinity-declared-on-a-foreign-key-column-affect-join-speed-tp74183p74295.html Sent from the SQLite mailing list archive at Nabble.com. _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
