The typical way to break up OR predicates is with UNION. Note that your example doesn’t fit well with your indexes. Even if you omitted field1 from the predicate, you’d have field2 >= 1000 OR field3 >= 2000, which can’t use an index. If you had indexes on (field1, field2) and (field1,field3) or field2 or … Read more
Composite indexes work just like regular indexes, except they have multi-values keys. If you define an index on the fields (a,b,c) , the records are sorted first on a, then b, then c. Example: | A | B | C | ————- | 1 | 2 | 3 | | 1 | 4 | 2 … Read more
The problem is that you have defined each of the dependent columns as foreign keys separately, when that’s not really what you intend, you of course want a composite foreign key. Sqlalchemy is responding to this by saying (in a not very clear way), that it cannot guess which foreign key to use (firstName or … Read more
class CompositeListener implements OnEventListener { private List<OnEventListener> registeredListeners = new ArrayList<OnEventListener>(); public void registerListener (OnEventListener listener) { registeredListeners.add(listener); } public void onEvent(Event e) { for(OnEventListener listener:registeredListeners) { listener.onEvent(e); } } } ….. CompositeListener composite = new CompositeListener(); composite.registerListener(listener1); composite.registerListener(listener2); component.setOnEventListener(composite);
Faster with hstore Since Postgres 9.0, with the additional module hstore installed in your database there is a very simple and fast solution with the #= operator that … replace[s] fields in record with matching values from hstore. To install the module: CREATE EXTENSION hstore; Examples: SELECT my_record #= ‘”field”=>”value”‘::hstore; — with string literal SELECT … Read more
Given that canvas is a canvas element or an OffscreenCanvas object, const context = canvas.getContext(‘2d’); context.clearRect(0, 0, canvas.width, canvas.height);