Soft State Based Query Result Cache

The soft state based query result cache (SQRC) on the hub caches - if requested by the provider application - the result of a READ_ENITITYSET request and applies paging on the result list. Consecutive paging requests for the same query result will then be served from that cache.

A GET for an entity set is requested by a client. This will be handled by the SRQC if the following conditions apply:

• The corresponding service has been enables for soft state in transaction /IWFND/MAINT_SERVICE by the provider application supported.

  Note

  Note that component IW_FND and IW_BEP both have to be at least on SAP Gateway 2.0 SP09 or component SAP_GWFND is on SAP NetWeaver 7.40 SP08.

• SQRC is supported by the provider application.

• SQRC is not disables on the backend.

• Consecutive client requests are a GET on the same Entity Set.

  The only difference between the request URLs are the values of the $top and $skip system query options. The rest of the URL must be identical.

It is recommended to use SQRC only if all the following conditions apply:

• The data retrieval is very expensive (slow).

• The data retrieval cannot be made any faster.

  For example, the data is retrieved from an underlying business framework which is not owned by the provider application. But even in this case it is best to address possible performance issues after they have occurred.

• Avoid caching large Entity Sets.

  If an Entity Set might contain thousands or even hundreds of thousands of entries, filtering must always be used first. The provider application might, for example, refuse the first READ_ENITITYSET if no adequate filter has been provided.

You can switch off SQRC on the SAP Gateway server. If you experience memory peaks due to the SQRC on the hub server, we recommend to deactivate the SQRC to improve memory consumption.

To disable SQRC proceed as follows:

1. In the Implementation Guide (IMG) for SAP NetWeaver navigate to  SAP Gateway Service Enablement  Backend OData Channel  Service Development for Backend OData Channel  Maintain Service .

2. Enter the technical service name of your service and choose Display.

3. Choose Configuration.

4. On screen Change Configuration activate option Deactivate Soft State based Query Result Cache.

5. Save your settings.

The default configuration is an active SQRC.

See also Soft State Support for OData Services.