DBA / Database

How to implement partial transaction rollback (not full, but up to a certain point)?.

What is a CTE (Common Table Expression)? What are the advantages? Is the CTE materialized?

What is a package of procedures? What does it consist of?

What index is suitable if the column has few unique values and many NULL values?

Are multiple DML operations executed in a single transaction in the procedure?

What can be done if an index is not used due to a function on a column?

Tell me about types of indexes. What are they and which ones have you used most often?

Have you heard of Nested Loop Join? What is it and when is it used?

How to return a value from a procedure using a REF CURSOR?

Have you worked with triggers? What did you use them for? What types of triggers do you know (ROW vs STATEMENT)?

You mentioned process optimization. What exactly did you do for that?

What is a transaction? Name the ACID principles.

If a transaction is rolled back, will the log table record made via a regular INSERT be preserved?

What are the transaction isolation levels in Oracle? Which is the default? What is the difference between READ COMMITTED and SERIALIZABLE?

Have you worked with exceptions? What types of exceptions are there in PL/SQL?

We have a SELECT query on a date column with a B-Tree index. The query runs slowly, and the plan shows that the index is not used. Why?

What is the difference between a function and a procedure?

What are hints in Oracle? Have you used any?

You mentioned bulk operations. Tell me more about the BULK COLLECT and FORALL combination.

What is DBLink? How have you used it? Architectural solutions?