Patch to apply a numeric primary key to caldav_data / calendar_item

in order to attempt to resolve performance issues in non-POSIX collation.

dba/patches/1.1.12.sql

@@ -0,0 +1,68 @@
+
+-- Add a numeric primary key link between caldav_data and calendar_item to
+-- provide more efficient linking when the db has been initialised with a
+-- non POSIX collation.
+
+
+BEGIN;
+SELECT check_db_revision(1,1,11);
+
+-- Add a column to the collection table to allow us to mark collections
+-- as publicly readable
+ALTER TABLE collection ADD COLUMN publicly_readable BOOLEAN DEFAULT FALSE;
+
+-- Add a numeric dav_id to link the caldav_data and calendar_item tables
+ALTER TABLE caldav_data ADD COLUMN dav_id INT8;
+ALTER TABLE calendar_item ADD COLUMN dav_id INT8;
+CREATE SEQUENCE caldav_data_dav_id_seq;
+
+CREATE or REPLACE FUNCTION sync_dav_id ( ) RETURNS TRIGGER AS '
+  DECLARE
+  BEGIN
+
+    IF TG_OP = ''DELETE'' THEN
+      -- Just let the ON DELETE CASCADE handle this case
+      RETURN OLD;
+    END IF;
+
+    IF NEW.dav_id IS NULL THEN
+      NEW.dav_id = nextval(''caldav_data_dav_id_seq'');
+    END IF;
+
+    IF OLD.dav_id = NEW.dav_id THEN
+      -- Nothing to do
+      RETURN NEW;
+    END IF;
+
+    IF TG_RELNAME = ''caldav_data'' THEN
+      UPDATE calendar_item SET dav_id = NEW.dav_id WHERE user_no = NEW.user_no AND dav_name = NEW.dav_name;
+    ELSE
+      UPDATE caldav_data SET dav_id = NEW.dav_id WHERE user_no = NEW.user_no AND dav_name = NEW.dav_name;
+    END IF;
+
+    RETURN NEW;
+
+  END
+' LANGUAGE 'plpgsql';
+
+CREATE TRIGGER caldav_data_sync_dav_id AFTER INSERT OR UPDATE ON caldav_data
+    FOR EACH ROW EXECUTE PROCEDURE sync_dav_id();
+
+CREATE TRIGGER calendar_item_sync_dav_id AFTER INSERT OR UPDATE ON calendar_item
+    FOR EACH ROW EXECUTE PROCEDURE sync_dav_id();
+
+-- Now, using the trigger, magically assign dav_id to all rows in caldav_data and calendar_item
+UPDATE caldav_data SET dav_id = dav_id;
+
+-- Finally, what we are really after, create the foreign key constraints
+ALTER TABLE caldav_data DROP CONSTRAINT caldav_data_pkey CASCADE;
+ALTER TABLE caldav_data ADD PRIMARY KEY ( dav_id );
+ALTER TABLE calendar_item DROP CONSTRAINT calendar_item_pkey CASCADE;
+ALTER TABLE calendar_item ADD PRIMARY KEY ( dav_id );
+ALTER TABLE calendar_item ADD CONSTRAINT "calendar_item_dav_id_fkey" FOREIGN KEY (dav_id) REFERENCES caldav_data(dav_id) ON UPDATE CASCADE ON DELETE CASCADE DEFERRABLE;
+
+SELECT new_db_revision(1,1,12, 'December' );
+
+COMMIT;
+ROLLBACK;
+