Full table scan in Oracle

When Oracle performs a full table scan, it will read db_file_multiblock_read_count blocks at once.

Oracle only reads blocks below the high water mark in a full table scan.

It is possible to find out which blocks in the buffer cache were read during a full table scan: see this link.

In a full table scan, Oracle reads db_file_multiblock_read_count database blocks at once. The wait event associated with full table scan reads are called db file scattered read.