https://www.oraclescripts.com/tags/cache-flushing/Recent content in Cache Flushing on Oracle ScriptsHugo -- gohugo.ioenOracleScripts.comThu, 27 Aug 2026 00:00:00 +0000https://www.oraclescripts.com/post/flush-the-shared-pool-and-buffer-cache-with-alter-system/Thu, 27 Aug 2026 00:00:00 +0000https://www.oraclescripts.com/post/flush-the-shared-pool-and-buffer-cache-with-alter-system/ <h2 id="flush-the-shared-pool-and-buffer-cache-with-alter-system">Flush the Shared Pool and Buffer Cache with ALTER SYSTEM</h2> <h2 id="purpose">Purpose</h2> <p>Where <code>DBMS_SHARED_POOL.PURGE</code> removes one cursor or one package from the library cache, <code>ALTER SYSTEM FLUSH SHARED_POOL</code> clears every parsed statement, stored procedure, function, package, and trigger cached in the shared pool at once — a blunt instrument standing next to a scalpel. <code>FLUSH BUFFER_CACHE</code> does the equivalent wipe on the other side of the SGA, discarding every cached data block across the <code>KEEP</code>, <code>RECYCLE</code>, and <code>DEFAULT</code> buffer pools in a single statement. Both clauses live under the same <code>ALTER SYSTEM</code> statement documented in the SQL Language Reference, and both exist for the same narrow reason: giving a DBA a clean, repeatable starting point when the question is &quot;how does this actually perform from cold,&quot; not &quot;how does it perform with yesterday's cache still warm.&quot;</p>