Oracle updating through a view
I read in oracle documentation (https://docs.oracle.com/cd/E11882_01/network.112/e4... Hi: I want to clean some space about some tables ,there are a few ways ,such as move ,shrink and impdp. I know when any changes are made to base tables then those changes are reflected are on view as well when view is refreshed. Dear Sir, I have created a table with a composite primary key and few indexes.I want to know which one is better regardless of space consideration and assume this tables can use all those methods. We have a load of legacy code that uses ORA_ROWSCN as an optimistic locking field. )-digit field for the host variable, and we experience horrible problems when the SCN ticks past the size that this can accommo... In one of the SQL the where clause is a combination of Index Column and non-index columns, however the query is not using the index column and instead going for Full Table Scan. Hello, Is there a way to get all the keys that exist in a JSON column? A view derives its data from the tables on which it is based. Views can be based on actual tables or another view also.Views are very powerful and handy since they can be treated just like any other table but do not occupy the space of a table.Additionally, inserting data is prohibited for the following types of views: Yes.The data "in" a view has no existence independent from the tables that make up the view.The following sections explain how to create, replace, and drop views using SQL commands. To see the empno, ename, sal, deptno, department name and location we have to give a join query like this.select e.empno,e.ename,e.sal,e.deptno,d.dname,From emp e, dept d where e.deptno=d.deptno; So everytime we want to see emp details and department names where they are working we have to give a long join query.
We can recompile a view using the Alter view statement, but oracle automatically recompiles the view once it is accessed.Instead of giving this join query again and again, we can create a view on these table by using a CREATE VIEW command given below create view emp_det as select e.empno, e.ename,e.sal,e.deptno,d.dname,from emp e, dept d where e.deptno=d.deptno; Now to see the employee details and department names we don’t have to give a join query, we can just type the following simple query.select * from emp_det; This will show same result as you have type the long join query.JSON_VALUE function provides an easy way to access a value for a given key, but is there a way to obtain all the key names? Hello Tom, Is there a way to identify SQL queries that are consuming the majority of the shared pool for e.g Session #1 is using 56 kbsession #2 is 10mb I would want to identify each query and the memory value it's consuming. Hello Tom & Team, Can you please provide to get the list of sql ids along with elasped times and other metrics for a given sql statment.Once obtained, can i force oracle to use a particular sql id which was performing better ? Hi, I would like to fing whats the best way to allow user to truncate table that is own by some one else thru forms on-line basis.
The view is, in essence, a stored SELECT statement that masquerades as a table.