CST 363 - Introduction to Database - Week 5

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The website "Use the Index Luke" has a page on "slow indexes" https://use-the-index-luke.com/sql/anatomy/slow-indexes 

If indexes are supposed to speed up performance of query, what does the author mean by a slow index? The author refers to a "slow index" as an index lookup process that becomes inefficient due to the need for additional steps beyond the initial tree transversal. Indexes can become slow if the query requires the database to follow the leaf node chain extensively or perform numerous table data accesses for each matching entry. A slow index results from the combination of leaf node chain transversal and accessing table data, causing the overall query performance to degrade despite the presence of an index. 

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