Amend trigger function Additional column names given as arguments to the trigger function will be tested for equality along with the geometry. This allows to implement behavior similar to a multi-column unique constraint (in preparation to store historic versions of axis segments with differing temporal validity). Using EXISTS instead of the aggregate should be more efficient.

--- a/schema/version.sql	Wed Mar 11 10:59:34 2020 +0100
+++ b/schema/version.sql	Wed Mar 11 11:24:20 2020 +0100
@@ -1,1 +1,1 @@
-INSERT INTO gemma_schema_version(version) VALUES (1421);
+INSERT INTO gemma_schema_version(version) VALUES (1422);