Hi, $SUBJECT,because anyway after the next transaction starts XactReadOnly is going to change depending on either RecoveryInProgress() or DefaultXactReadOnly GUC ,so if there's no specific use to set transaction_read_only GUC can we change its GucContext from PGC_USERSET to PGC_INTERNAL and remove check_transaction_read_only api which makes it clear that we can't set it externally and only we can use SHOW on it, thoughts?