https://www.oraclescripts.com/tags/vlibrarycache/Recent content in V$librarycache on Oracle ScriptsHugo -- gohugo.ioenOracleScripts.comFri, 06 Nov 2026 00:00:00 +0000https://www.oraclescripts.com/post/measure-the-library-cache-hit-ratio-with-v-librarycache/Fri, 06 Nov 2026 00:00:00 +0000https://www.oraclescripts.com/post/measure-the-library-cache-hit-ratio-with-v-librarycache/ <h2 id="measure-the-library-cache-hit-ratio-with-vlibrarycache">Measure the Library Cache Hit Ratio with V$LIBRARYCACHE</h2> <h2 id="purpose">Purpose</h2> <p><a href="https://docs.oracle.com/en/database/oracle/oracle-database/19/refrn/V-LIBRARYCACHE.html"><code>V$LIBRARYCACHE</code></a> contains statistics about library cache performance and activity, split by namespace. The script reads four counters for each namespace. They show how many times objects were pinned, how many of those pins found everything in memory, how many pins had to load the object again, and how many times objects were marked invalid.</p> <p>The counters are cumulative. They reflect all library cache activity <a href="https://docs.oracle.com/en/database/oracle/oracle-database/19/tgdba/tuning-shared-pool-and-large-pool.html">after the most recent database instance startup</a>. A low pin hit rate or a high reload count points to repeated hard parsing. Each hard parse needs more CPU, more library cache latch gets and more shared pool latch gets.</p>