[MonetDB-users] Trigger definitions - ambiguous identifier error

I've the following table on my database :

\d sys.subscriber_data CREATE TABLE "sys"."subscriber_data" ( "subs_id" BIGINT, "imsi" VARCHAR(16), "mccmnc" INTEGER, "msisdn" VARCHAR(16), "imei" VARCHAR(16), "time_idx_print" BIGINT, "time_idx_lastmodified" BIGINT, "time_idx_purge" BIGINT, "merge_subs_id" BIGINT );

I want to create a specific trigger to delete old data in table before insert new data.

create trigger oninsert_subscriber before insert on subscriber_data referencing NEW ROW AS new_ident for each row begin atomic delete from subscriber_data where subscriber_data.subs_id = new_ident.subs_id; end;

When I executed the statement, I get this error message : SELECT: identifier 'subs_id' ambiguous

I don't understand how to use alias in this case to reference old and new data.

I wrote the statement according to the documentation: http://www.monetdb.org/Documentation/SQLreference/Triggers

However, I found this line in feature overview (unsupported) page T211 Basic trigger capability http://www.monetdb.org/Documentation/Manuals/SQLreference/Features/unsupport...

Does it mean triggers are not yet entirely supported by Monetdb?

Thanks for your help.