oracle 如何 监控数据变化
oracle 有没有办法监控 一个试图或者一个查询语句的结果发生变化，当查询结果发生变化的时候发出通知。
另外就是性能问题，我的这个表每年会由3亿条数据，而且新增操作非常频繁，每秒新增6条数据以上。
现在要做的是当出现符合条件的数据就向前台发通知，怎么样做效率会更高。
[解决办法]
1.Connect to the database AS SYSDBA.
2.Grant the required privileges to HR:
GRANT EXECUTE ON DBMS_CQ_NOTIFICATION TO HR;
GRANT CHANGE NOTIFICATION TO HR;
3.Enable the JOB_QUEUE_PROCESSES parameter to receive notifications:
ALTER SYSTEM SET "JOB_QUEUE_PROCESSES"=4;
4.Connect to the database as a non-SYS user (such as HR).
5.Create database tables to hold records of notification events received:
-- Create table to record notification events.
DROP TABLE nfevents;
CREATE TABLE nfevents (
regid NUMBER,
event_type NUMBER
);
-- Create table to record notification queries:
DROP TABLE nfqueries;
CREATE TABLE nfqueries (
qid NUMBER,
qop NUMBER
);
-- Create table to record changes to registered tables:
DROP TABLE nftablechanges;
CREATE TABLE nftablechanges (
qid NUMBER,
table_name VARCHAR2(100),
table_operation NUMBER
);
-- Create table to record ROWIDs of changed rows:
DROP TABLE nfrowchanges;
CREATE TABLE nfrowchanges (
qid NUMBER,
table_name VARCHAR2(100),
row_id VARCHAR2(2000)
);
CREATE OR REPLACE PROCEDURE chnf_callback (
ntfnds IN CQ_NOTIFICATION$_DESCRIPTOR
)
IS
regid NUMBER;
tbname VARCHAR2(60);
event_type NUMBER;
numtables NUMBER;
operation_type NUMBER;
numrows NUMBER;
row_id VARCHAR2(2000);
numqueries NUMBER;
qid NUMBER;
qop NUMBER;
BEGIN
regid := ntfnds.registration_id;
event_type := ntfnds.event_type;
INSERT INTO nfevents (regid, event_type)
VALUES (chnf_callback.regid, chnf_callback.event_type);
numqueries :=0;
IF (event_type = DBMS_CQ_NOTIFICATION.EVENT_QUERYCHANGE) THEN
numqueries := ntfnds.query_desc_array.count;
FOR i IN 1..numqueries LOOP -- loop over queries
qid := ntfnds.query_desc_array(i).queryid;
qop := ntfnds.query_desc_array(i).queryop;
INSERT INTO nfqueries (qid, qop)
VALUES(chnf_callback.qid, chnf_callback.qop);
numtables := 0;
numtables := ntfnds.query_desc_array(i).table_desc_array.count;
FOR j IN 1..numtables LOOP -- loop over tables
tbname :=
ntfnds.query_desc_array(i).table_desc_array(j).table_name;
operation_type :=
ntfnds.query_desc_array(i).table_desc_array(j).Opflags;
INSERT INTO nftablechanges (qid, table_name, table_operation)
VALUES (
chnf_callback.qid,
tbname,
operation_type
);
IF (bitand(operation_type, DBMS_CQ_NOTIFICATION.ALL_ROWS) = 0) THEN
numrows := ntfnds.query_desc_array(i).table_desc_array(j).numrows;
ELSE
numrows :=0; -- ROWID info not available
END IF;
-- Body of loop does not run when numrows is zero.
FOR k IN 1..numrows LOOP -- loop over rows
Row_id :=
ntfnds.query_desc_array(i).table_desc_array(j).row_desc_array(k).row_id;
INSERT INTO nfrowchanges (qid, table_name, row_id)
VALUES (chnf_callback.qid, tbname, chnf_callback.Row_id);
END LOOP; -- loop over rows
END LOOP; -- loop over tables
END LOOP; -- loop over queries
END IF;
COMMIT;
END;
/
DECLARE
reginfo CQ_NOTIFICATION$_REG_INFO;
mgr_id NUMBER;
dept_id NUMBER;
v_cursor SYS_REFCURSOR;
regid NUMBER;
BEGIN
/* Register two queries for QRNC: */
/* 1. Construct registration information.
chnf_callback is name of notification handler.
QOS_QUERY specifies result-set-change notifications. */
reginfo := cq_notification$_reg_info (
'chnf_callback',
DBMS_CQ_NOTIFICATION.QOS_QUERY,
0, 0, 0
);
/* 2. Create registration. */
regid := DBMS_CQ_NOTIFICATION.new_reg_start(reginfo);
OPEN v_cursor FOR
SELECT dbms_cq_notification.CQ_NOTIFICATION_QUERYID, manager_id
FROM HR.EMPLOYEES
WHERE employee_id = 7902;
CLOSE v_cursor;
OPEN v_cursor FOR
SELECT dbms_cq_notification.CQ_NOTIFICATION_QUERYID, department_id
FROM HR.departments
WHERE department_name = 'IT';
CLOSE v_cursor;
DBMS_CQ_NOTIFICATION.reg_end;
END;
/
SELECT queryid, regid, TO_CHAR(querytext)
FROM user_cq_notification_queries;
UPDATE DEPARTMENTS
SET DEPARTMENT_NAME = 'FINANCE'
WHERE department_name = 'IT';
SELECT * FROM nftablechanges;
SELECT * FROM nfrowchanges;
