Search Results set_cache

Overview

SYS.OWA_CACHE is the Oracle Web Agent (OWA) caching package that provides the PL/SQL interface used by the Oracle HTTP Server (mod_plsql) and Oracle E-Business Suite Apache/OC4J components to emit HTTP cache-control response headers. Within the EBS 12.1.1 and 12.2.2 technology stack it forms part of the foundation used by the Oracle Application Framework (OAF), the Oracle Applications Manager (OAM), and standard EBS Web-based products that render pages through mod_plsql. The package does not itself store cached content; rather, it generates the directive headers (Expires, Cache-Control, ETag, and Surrogate-Control) that instruct downstream proxies, browsers, and Oracle Web Cache how long a page may be reused and under what validation conditions. Its API classification is OTHER, and it is owned by SYS, which underscores its role as a low-level infrastructure utility rather than an application business API.

Key Procedures and Functions

The documented interface exposes eight procedures and functions:

• INIT — Reserves header space in the HTP output buffer prior to any content being written. It must be called before data is emitted to the buffer.
• DISABLE — Disables caching for the current response.
• SET_EXPIRES — Establishes the freshness lifetime in minutes together with a caching level (USER or SYSTEM). Raises VALUE_ERROR for a non-positive or excessively large expiry value, or an invalid level.
• SET_CACHE — Emits the cache headers for a response, taking an ETag and a caching level. Raises VALUE_ERROR when the ETag exceeds the permitted length or the level is invalid. This is the procedure typically associated with the "set_cache" search term.
• SET_NOT_MODIFIED — Emits the headers for a cache hit where the client's cached copy is still valid, raising VALUE_ERROR if no ETag was previously supplied.
• SET_SURROGATE_CONTROL — Sets Surrogate-Control headers used by Oracle Web Cache and similar surrogate caches to define their own caching policy independent of browser directives.
• GET_LEVEL — Returns the caching level currently in effect.
• GET_ETAG — Returns the ETag associated with the current response.

Tables Accessed

No application tables are documented as referenced by this package through APPS synonyms. OWA_CACHE operates entirely in memory against the HTP output buffer and PL/SQL package state, emitting HTTP headers rather than persisting data. Any caching state it influences resides in external caches such as the browser cache, intervening proxies, or Oracle Web Cache.

Usage Notes

OWA_CACHE is typically invoked from PL/SQL procedures that generate dynamic Web pages through mod_plsql. A procedure calls INIT to reserve header space, then SET_EXPIRES or SET_CACHE to declare freshness and validation data, using SET_NOT_MODIFIED when a conditional request matches a previously issued ETag, and SET_SURROGATE_CONTROL for surrogate caches. DISABLE, GET_LEVEL, and GET_ETAG support inspection and suppression of caching. The package is referenced by at least one other package, confirming its role as a shared infrastructure dependency. Custom EBS extensions that produce PL/SQL Web pages can call these procedures directly to control client-side and server-side caching behavior.