Re: Behavior of identity columns

Hello,
I see 'identity' column values increment even when some error(s) occurs while inserting data.  Is that a known bug or known behavior?
Create script of table:**************************** CREATE TABLE public.users(    id integer NOT NULL GENERATED ALWAYS AS IDENTITY ( INCREMENT 1 START 1 MINVALUE 1 MAXVALUE 2147483647 CACHE 1 ),    username character varying(255) COLLATE pg_catalog."default",    email character varying(255) COLLATE pg_catalog."default",    first_name character varying(255) COLLATE pg_catalog."default",    last_name character varying(255) COLLATE pg_catalog."default",    CONSTRAINT users_pkey PRIMARY KEY (id),    CONSTRAINT "test_UX" UNIQUE (username))WITH (    OIDS = FALSE)TABLESPACE pg_default;
ALTER TABLE public.users    OWNER to postgres;***********************************column id is int and identity columncolumn username is unique
When I insert data that violates the unique constraint, I see that the id value gets incremented. And I see missing values in between when I add the correct data next time.
my Insert SQLinsert into users (username, email, first_name, last_name) values ('ONE', 'one(at)gmail(dot)com', 'one', '1'); // id = 1insert into users (username, email, first_name, last_name) values ('ONE', 'one(at)gmail(dot)com', 'one', '1'); // Insert failsinsert into users (username, email, first_name, last_name) values ('TWO', 'one(at)gmail(dot)com', 'one', '1'); // id = 3insert into users0(username, email, first_name, last_name) values ('TWO', 'one(at)gmail(dot)com', 'one', '1'); // insert fails as there is no users0 tableinsert into users (username, email, first_name, last_name) values ('THREE', 'one(at)gmail(dot)com', 'one', '1'); // id = 5
ID gets incremented even when some wrong table name is mentioned in the query. Check 4th query.
Is it a known behavior or a known bug?

Happiness AlwaysBKR Sivaprakash