FW: help with serial

Hi all,

There’s a behaviour I can’t understand!!!!

There is table TABLE_A with 3 columns (uid, id, session) where uid is the pk and the data type is serial.

There is table TABLE_B with 3 columns (uid, ts_col, col) where uid is the pk.

On table TABLE_A I have a rule on insert like this:

CREATE OR REPLACE RULE r1 AS

    ON INSERT TO TABLE_A DO  INSERT INTO TABLE_B (uid)

  VALUES ((new.uid));

Till now… ok…

When I do an insert

insert into TABLE_A ("id", "session") values (7, 'aaaaaaaaaaaaa');

I have this row,

In table TABLE_A

37; 7; "aaaaaaaaaaaaa"

while in table TABLE_B

38; ""; ""

how is it possible, why in a table 37 and in the other 37 + 1?

Thank you,

Luca