# Index Operations: When to Use Seek? > [!Note] > `SQL Server’s **Index Seek** navigates the B-Tree to locate specific rows efficiently; it excels with **equality**, **range**, **prefix**, and **IN-list** predicates on indexed columns, minimizing I/O compared to full scans.` An Index Seek traverses the B-Tree structure—much like looking up a term in a book’s index—to jump directly to matching rows. Once the engine reaches the first qualifying leaf page, it can scan adjacent pages for contiguous matches, delivering high performance for selective predicates. Unlike an **Index Scan**, which reads every leaf page, a Seek prunes away irrelevant branches early and focuses I/O only where it’s needed. > [!tip] > Ensure that your WHERE clause aligns with an existing index on the targeted column(s); otherwise, the optimizer cannot perform a Seek. Below is a concise summary of the scenarios where an Index Seek is most effective: |**Predicate Type**|**Example**|**Behavior**| |---|---|---| |**Exact Match**|`ProductID = 771`|Seeks directly to the matching key and returns the single row.| |**Range Comparison**|`UnitPrice BETWEEN 5 AND 10`|Seeks to the lower bound, then scans forward until the upper bound is exceeded.| |**Prefix Search**|`LastName LIKE 'Brown%'`|Seeks to the first “Brown” entry, then scans leaf pages for all entries starting with “Brown”.| |**List of Values**|`ProductID IN (10, 20, 30)`|Performs multiple discrete seeks—one per listed value—and merges the results.| > [!info] > Supported operators for Seek include `=, <, >, <=, >=, <>, !=, !<, !>, BETWEEN, IN`—provided there’s an appropriate index on the referenced column. By leveraging Seeks for these patterns, you can dramatically reduce the number of pages read, lower CPU consumption, and accelerate query execution—especially in high-concurrency OLTP environments. --- ## ## References - Korotkevitch, D. (2022). _SQL Server advanced troubleshooting and performance tuning: Best practices and techniques_. O’Reilly Media. - Nevarez, B. (2022). _SQL Server query tuning and optimization: Optimize Microsoft SQL Server 2022 queries and applications_. Packt Publishing.