メッセージが例外キューに入るように、Oracle aq のエンキュー/デキュー/ブラウズ中に例外をシミュレートする方法。私は初心者で、まだ加入者と消費者を通過していません。私がやったことは----
BEGIN dbms_aqadm.drop_queue_table (
queue_table => 'demo_queue_table',
force => TRUE);
END;
--------------------- Creation of queue table
BEGIN
DBMS_AQADM.CREATE_QUEUE_TABLE (
queue_table => 'demo_queue_table',
queue_payload_type => 'demo_queue_payload_type'
);
END;
-------------------- Creation and starting of the queue
BEGIN
DBMS_AQADM.CREATE_QUEUE (
queue_name => 'demo_queue',
queue_table => 'demo_queue_table'
);
DBMS_AQADM.START_QUEUE (
queue_name => 'demo_queue'
);
END;
---------------------Exception Queue
BEGIN
dbms_aqadm.create_queue(
queue_name => 'demo_queue_e',
queue_table => 'demo_queue_table',
queue_type => DBMS_AQADM.EXCEPTION_QUEUE,
dependency_tracking => FALSE,
comment => 'EXCEPTION QUEUE OF DEMO QUEUE TABLE');
-- start queue
dbms_aqadm.start_queue('DEMO_QUEUE_E',enqueue => FALSE, dequeue => TRUE);
END;
BEGIN
dbms_aqadm.start_queue('AQ$_DEMO_QUEUE_TABLE_E',enqueue => FALSE, dequeue => TRUE);
END;
------------- Enqueue with Exception queue specified
DECLARE
r_enqueue_options DBMS_AQ.ENQUEUE_OPTIONS_T;
r_message_properties DBMS_AQ.MESSAGE_PROPERTIES_T;
v_message_handle RAW(16);
o_payload demo_queue_payload_type;
BEGIN
o_payload := demo_queue_payload_type('Message');
r_message_properties.exception_queue := 'DEMO_QUEUE_E';
DBMS_AQ.ENQUEUE(
queue_name => 'demo_queue',
enqueue_options => r_enqueue_options,
message_properties => r_message_properties,
payload => o_payload,
msgid => v_message_handle
);
DBMS_OUTPUT.PUT_LINE('*** Exception Queue is [' || o_payload.message || '] ***');
DBMS_OUTPUT.PUT_LINE('*** Exception Queue is [' || r_message_properties.exception_queue || '] ***');
COMMIT;
END;
------------------------------ BRowse
DECLARE
r_dequeue_options DBMS_AQ.DEQUEUE_OPTIONS_T;
r_message_properties DBMS_AQ.MESSAGE_PROPERTIES_T;
v_message_handle RAW(16);
o_payload demo_queue_payload_type;
BEGIN
r_dequeue_options.dequeue_mode := DBMS_AQ.REMOVE;
DBMS_AQ.DEQUEUE(
queue_name => 'demo_queue',
dequeue_options => r_dequeue_options,
message_properties => r_message_properties,
payload => o_payload,
msgid => v_message_handle
);
DBMS_OUTPUT.PUT_LINE('*** Browsed message is [' || o_payload.message || '] ***');
-- DBMS_OUTPUT.PUT_LINE('*** Browsed message is [' || r_message_properties.exception_queue || '] ***');
END;
-----------------------------------Dequeue
DECLARE
r_dequeue_options DBMS_AQ.DEQUEUE_OPTIONS_T;
r_message_properties DBMS_AQ.MESSAGE_PROPERTIES_T;
v_message_handle RAW(16);
o_payload demo_queue_payload_type;
no_messages exception;
pragma exception_init (no_messages, -25263);
BEGIN
DBMS_AQ.DEQUEUE(
queue_name => 'demo_queue',
dequeue_options => r_dequeue_options,
message_properties => r_message_properties,
payload => o_payload,
msgid => v_message_handle
);
DBMS_OUTPUT.PUT_LINE('*** Dequeued message is [' || o_payload.message || '] ***');
COMMIT;
END;
---------------------------------start the error queue---------------------------------------------
exec dbms_aqadm.start_queue('AQ$_DEMO_QUEUE_TABLE_E',false, true);
私は今、エンキュー、デキュー、ブラウズ機能に慣れています。例外キューがどのように機能するかを確認し、例外キュー (ブラウズとデキュー) でいくつかの実験を行いたいだけです。理論的には、例外キューに入れることはできません。そのため、エンキュー、デキュー、またはブラウズ中にメッセージが例外キューに入るシナリオを生成する必要があります。