sqlpostgresqlpostgresql-11exclusion-constraint

Postgresql EXCLUDE constraint not triggering ON CONFLICT when INSERT

I have defined this table:

CREATE TABLE market.price_history (
    item_id bigint NOT NULL,
    valid_time tstzrange DEFAULT tstzrange(now(), 'infinity'),
    sale_price money NOT NULL,
    promo_code bool NOT NULL DEFAULT false,
    EXCLUDE USING gist(item_id WITH =, valid_time WITH &&),
    EXCLUDE USING gist(item_id WITH =, sale_price WITH =, valid_time WITH &&)
);

But when I'm doing this SQL:

WITH new_row_valid_time as(
    SELECT tstzrange(MAX(upper(valid_time)), 
                     'infinity'::timestamptz) as adjacent_valid_time 
    FROM market.price_history 
    WHERE item_id = 11
)
INSERT INTO market.price_history as ph
(item_id, valid_time, sale_price, promo_code)
VALUES(11,                        -- same id as existent row
       (SELECT adjacent_valid_time 
        FROM new_row_valid_time), -- adjacent range for existent row
       11.83,                     -- same price as the existent row
       False)
ON CONFLICT (item_id, sale_price, valid_time) DO
UPDATE SET valid_time = tstzrange(lower(ph.valid_time), 'infinity'::timestamptz)
WHERE ph.item_id = excluded.item_id
    AND ph.sale_price = excluded.sale_price
    AND upper(ph.valid_time) = lower(excluded.valid_time);

I'm expecting the ON CONFLICT clause to be executed, given that there is some row to be inserted having the same item_id, sale_price and a valid_time adjacent to the existent one. Instead I'm getting this:

ERROR:  there is no unique or exclusion constraint matching the ON CONFLICT specification

Do I misunderstand something? I believe the exclusion constraint in the second EXCLUDE clause involves the same 3 columns. I'm searching the docs but the ON CONFLICT instructions are not that clear to me.

Solution

  • The documentation somewhat tersely remarks:

    Note that exclusion constraints are not supported as arbiters with ON CONFLICT DO UPDATE.

    Looking at the source code makes the case clearer: