186 OWA_CACHE

Using OWA_CACHE

• Constants

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Constants

• system_level CONSTANT VARCHAR(6) := 'SYSTEM';

• user_level CONSTANT VARCHAR(4) := 'USER';

Summary of OWA_CACHE Subprograms

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DISABLE Procedure

This procedure disables the cache for this particular request.

Syntax

OWA_CACHE.DISABLE;

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GET_ETAG Function

This function returns the tag associated with the cached content. It is used in the Validation technique only.

Syntax

OWA_CACHE.GET_ETAG
  RETURN VARCHAR2;

Return Values

The tag for cache hit, otherwise NULL.

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GET_LEVEL Function

This returns the caching level. It is used in the Validation technique model only.

Syntax

OWA_CACHE.GET_LEVEL
  RETURN VARCHAR2;

Return Values

The caching level string ('USER' or 'SYSTEM') for cache hit, otherwise NULL.

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SET_CACHE Procedure

This sets up the cache headers for validation model cache type.

Syntax

OWA_CACHE.SET_CACHE(
   p_etag        IN       VARCHAR2,
   p_level       IN       VARCHAR2);

Parameters

Exceptions

VALUE_ERROR is thrown if

• p_etag is greater than 55

• p_level is not 'USER' or 'SYSTEM'

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SET_EXPIRES Procedure

This procedure sets up the cache headers for expires model cache type.

Syntax

OWA_CACHE.SET_EXPIRES(
   p_expires      IN       NUMBER,
   p_level        IN       VARCHAR2);

Parameters

Exceptions

VALUE_ERROR is thrown if

• p_expires is negative or zero

• p_level is not 'USER' or 'SYSTEM'

• p_expires is > 525600 (1 year)

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SET_NOT_MODIFIED Procedure

This procedure sets up the headers for a not-modified cache hit. It is used in the Validation technique only.

Syntax

OWA_CACHE.SET_NOT_MODIFIED;

Exceptions

VALUE_ERROR is thrown if If the etag was not passed in

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SET_SURROGATE_CONTROL Procedure

This procedure sets the headers for a surrogate-control header for Web cache

Syntax

OWA_CACHE.SET_SURROGATE_CONTROL(
   p_value        IN       VARCHAR2);

Parameters

Exceptions

VALUE_ERROR is thrown if If p_value is greater than 55 in length.