Expression 'obotsl txts GET GET with query strng GET GET ExpressionIpdfs ith query N/A Cach GET GET ith query N/A GET GET t htmlas ith query N/A 29 Regular tht GET with query strng GET GET with query N/A N/A GET GET 31 Expession giftie?gs with query N/A Cache Figure3:Samplestaticcachingrulesforwww.oracle.comasdisplayedintheWebCacheManag administrative user interfa When configuring OracleAs Web Cache, administrators use caching policies to specify which content to cache and which content not to cache. 3 OracleAs Web Cache supports caching of static content, such as GIF and PEG images, as well as non-transactional content created dynamic pag age generation technologies, such as JavaServer Pages (SP), Active Server Pages(ASP), PL/SQL Server Pages(PSp), Java Servlets, Common Gateway Interface(CGD), PHP, Python, ColdFusion, and many others Note that dynamically generated content was, until very recently, considered non- cacheable. This is in part due to the ephemeral nature of this content; another reason is that it is difficult to map HTML-formatted content to the relational tables and materialized views used to generate the content. As discussed later in this paper, the invalidation and capacity heuristics mechanisms supported by OracleAs Web Cache help circumvent this difficulty quite nicely 3 Note that most caching policies can be expressed at development time using surrogate-control headers, c aking the content self-describing and the configuration of rules unnecessary. Rules expressed in surrogate- trol headers override those expressed in the configuration. OracleS Web Cache 10g(1 Technical White Pape ation, All Rights ReservedPage 11 OracleAS Web Cache 10g (10.1.2) -- Technical White Paper Copyright © 1999-2005 Oracle Corporation, All Rights Reserved Figure 3: Sample static caching rules for www.oracle.com, as displayed in the Web Cache Manager administrative user interface. When configuring OracleAS Web Cache, administrators use caching policies to specify which content to cache and which content not to cache.3 OracleAS Web Cache supports caching of static content, such as GIF and JPEG images, as well as non-transactional content created using dynamic page generation technologies, such as JavaServer Pages (JSP), Active Server Pages (ASP), PL/SQL Server Pages (PSP), Java Servlets, Common Gateway Interface (CGI), PHP, Python, ColdFusion, and many others. Note that dynamically generated content was, until very recently, considered non￾cacheable. This is in part due to the ephemeral nature of this content; another reason is that it is difficult to map HTML-formatted content to the relational tables and materialized views used to generate the content. As discussed later in this paper, the invalidation and capacity heuristics mechanisms supported by OracleAS Web Cache help circumvent this difficulty quite nicely. 3 Note that most caching policies can be expressed at development time using surrogate-control headers, making the content self-describing and the configuration of rules unnecessary. Rules expressed in surrogate￾control headers override those expressed in the configuration