What is the benefit to use sequence rather than just insert and get generated ID in postgresql ? I mean why don't just insert a record and the rdbms generate ID for you?

CodePudding user response：

For most purposes, SERIAL does the same thing as a sequence can do. However, if you wanted your auto increment column to have a custom behavior, you might have to use a sequence. For example, let's say that you wanted the sequence to start at 100. Then you could use:

CREATE SEQUENCE your_seq
    START 101
    INCREMENT 1;

INSERT INTO yourTable (id, val)
VALUES (NEXTVAL('your_seq'), 'some text here');