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Oracle Index Fast Full Scan — multiblock I/O across all leaf blocks, no table access

Optimizer Access Paths : Fast Full Scan

Posted on by Sanjeeva Kumar

An index fast full scan reads the entire index as it is i.e. as it exists on the disk. This index read is unsorted. This access path usage multiblock IO to perform the index scan. Index fast full scan simply reads all of the leaf, branch and root block of index quickly using multiblock IO Read more about Optimizer Access Paths : Fast Full Scan[…]

Oracle DISTINCT query execution path comparison showing full table scan versus index fast full scan optimization

Optimizer Access Paths: How Index FFS works with Distinct

Posted on by Sanjeeva Kumar

Distinct is the keyword that oracle used to filter out unique values from a column. However, it is very interesting to see the behavior followed by the optimizer for its access path. How Oracle Index Fast Full Scan Handles DISTINCT Queries? In this “Optimizer Access Paths” blog, we will see how we can make optimizer Read more about Optimizer Access Paths: How Index FFS works with Distinct[…]