I use oracle as a database. I want to get the courses of last three semesters ordered by semester.

I’m trying to query the execution plan information that I see in Oracle Enterprise Manager (EM) using SQL. I have been pulling data from the V$SQL_PLAN view, but I’m unsure which child cursor to select when there are multiple CHILD_ADDRESS entries. Should I be selecting the one with the latest TIMESTAMP?

I have a cluster of Oracle RAC with 4 primary nodes
master 1, master2, master3, master 4
I want to know which master node generates an online redo log or archived redo log.
For example, if there is an online redo log with a sequence of 120, can I be sure that it was generated by a master node?
If the redo log sequence for an archive is 100, is it also certain that it was generated by a primary node?

I want to exclude combination of column values from the sql results.
sample table
The value of column1+column2+column3+column4 will be same as column3+column4+column1+column2 in any of the rows. I just want only one row value. Can someone help with the sql query.

I am having trouble with ORA-02437: cannot validate (FIDDLE_ZMSLRUPSPEPJBOYIFWON.PEOPLE1_PK) – primary key violateD. I have two identical tables. The first table I am able to create a primary key. I then use a select as statement to create an identical table. I would think I can alter the table to create the same primary key. I am not able to do so.

I have created an MV which calls a query over a DB link. When I create the object, the SQL passes validation and the MV is created.

In oracle I would like to check if a record exists before insert then if exist update the record.

In oracle I would like to create table from existing table with the primary key of the existing table. I know I can create people1 then alter people1 to have the primary key. Is there a way to modify create table people1 as (select * from people); to have id int primary key as the primary key?