hi. https://www.postgresql.org/docs/current/explicit-locking.html
FOR KEY SHARE > Behaves similarly to FOR SHARE, except that the lock is weaker: SELECT > FOR UPDATE is blocked, but not SELECT FOR NO KEY UPDATE. A key-shared > lock blocks other transactions from performing DELETE or any UPDATE that > changes the key values, but not other UPDATE, and neither does it prevent > SELECT > FOR NO KEY UPDATE, SELECT FOR SHARE, or SELECT FOR KEY SHARE. A key-shared lock blocks other transactions from performing DELETE or any > UPDATE that changes the key values querya: select col1,col2,col3 from a for key share of a Does "the key values" refer to these rows returned by the querya? I still feel confused about "the key values".
