In our previous blog, we talked about the optimizer access path. Over the last few blogs, we have walked through different access paths one by one. In this blog, we will see how the index unique scan works — and why it is the most efficient index access path Oracle has to offer. Index unique Read more about Optimizer Access Paths: index unique scan[…]
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[…]
Index full scan is the optimizer access path where the database reads the index from start to end, one block at a time. It reads the index starting from the root block, navigating down using branch towards the left side, or right side if we are doing a descending full scan until it hits the Read more about Optimizer Access Paths : What is Index Full Scan[…]
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. In this “Optimizer Access Paths” blog, we will see how we can make optimizer to use an index with a distinct keyword. Let’s Read more about Optimizer Access Paths: How Index FFS works with Distinct[…]