id increases even if the line has not been created

I was doing a simple crud on nestjs and using postgres, then i noticed something strange. I made an entity with a unique string column @Entity() export class Model { @PrimaryGeneratedColumn() id: number; @Column({unique:true}) name: string; } but then everytime i try to add a row, and if this row dont get added because the unique restriction it increases the current id of the database anyways, and then the next line jumps some ids. exemplifying: if i try to add a Model with name 'model 1', it will be id 1, since it's the first, but then, if i try to add 'model 1' 15 times, and it wont be added because i made the restriction, the next time i insert a row, like 'model 2' it will jump a lot of ids, and wont be 2, it will be 16. Is it how it should work? it looks like I am wasting ids for no reason.