In this blog, we will explore what is the access path in the Oracle database.
However, before moving to the access path, let’s first understand what is a row source. It is a set of rows that are returned in a step by execution plan. It can be a table or a result of join operations or a view etc.
Access path is how the database retrieves data from a database. It is actually a technique that is being used by a query to retrieve a row from a row source. It accepts only one-row source in unary operations and more than one-row source in binary operations. A Full table scan is a unary operation and a join query is a binary operation.
These access paths are:
- Full Table Scans
- Table Access by Rowid
- Sample Table Scans
- Index Unique Scans
- Index Range Scans
- Index Full Scans
- Index Fast Full Scans
- Index Skip Scans
- Index Join Scans
- Bitmap Index Single Value
- Bitmap Index Range Scans
- Bitmap Merge
- Bitmap Index Range Scans
- Cluster Scans
- Hash Scans
We will explore these access path in details in next few blogs.