e2open Oracle SQL and PLSQL Developer Interview Questions, Process, and Tips

To create a table using another table, use the CREATE TABLE AS SELECT statement.

• Use the CREATE TABLE AS SELECT statement to create a new table based on the structure and data of an existing table.

• Specify the new table name after CREATE TABLE and the existing table name after AS SELECT.

• You can also add conditions or filters to the SELECT statement to customize the data being copied.

• Example: CREATE TABLE new_table AS SEL

The question is asking to identify different types of joins in SQL.

• Inner Join: Returns rows when there is a match in both tables.

• Left Join: Returns all rows from the left table and the matched rows from the right table.

• Right Join: Returns all rows from the right table and the matched rows from the left table.

• Full Outer Join: Returns rows when there is a match in either table.

• Cross Join: Returns the Cartesian product of

An index is a database object that improves the speed of data retrieval operations on a table.

• Indexes can be created on one or more columns of a table.

• Syntax to create an index: CREATE INDEX index_name ON table_name(column_name);

• Indexes can be unique or non-unique.

• Indexes can be used to enforce uniqueness constraints.

• Indexes can improve query performance by reducing the number of rows that need to be scanned.

Use SQL query with MAX function to fetch highest salary from the database.

• Use SELECT statement with MAX function to retrieve highest salary

• Specify the column name for salary in the SELECT statement

• Include the table name in the query if needed

Use a DELETE statement with a subquery to remove duplicates in a table.

• Identify the columns that define duplicates

• Use a subquery to select the rows to be deleted

• Use the DELETE statement to remove the duplicates