Add some simple query plan evaluation test in the wc-queries-test. This test passes for Sqlite 3.7.12, but might (and probably will) fail for older Sqlite versions that lack specific optimizations.
Yes it would be much nicer to implement this in a script language... But no, that wouldn't help as that might test a different Sqlite version than Subversion.
* subversion/tests/libsvn_wc/wc-queries-test.c (slow_statements): New list. (is_schema_statement): Renamed to in_list and add list argument. (is_slow_statement, is_schema_statement): New macros. (explanation_item): New struct. (parse_explanation_item): New function. (is_node_table): New function. (test_query_expectations): New function. (test_funcs): Add test_query_expectations.