Method and apparatus for selective data caching implemented with noncacheable and cacheable data for improved cache performance in a computer networking system

In a computer network, an apparatus for selectively caching data, comprising:

• a first client computer coupled to the computer network for running an application program, wherein the first client computer includes a first local memory;
• a second client computer coupled to the computer network for running the application program, wherein the second client computer includes a second local memory;
• a mass storage device coupled to the computer network for storing data;
• and a server computer coupled to the first client computer, the second client computer and the mass storage device for handling read requests generated by the application program running on the first client computer and the second client computer, wherein the server computer is comprised of:
• a cache memory for temporarily storing data;
• and
• a cache controller coupled to the cache memory for controlling the cache memory, wherein requested data not currently residing in the cache memory is read from the mass storage device and selectively:
• (a) stored in the cache memory of the server computer if said request for data indicates the data is not exempt from being cached;
• (b) not stored in the cache memory of the server computer and stored into the first local memory of the first client computer if said request for data indicates the data is exempt from being cached;
• and
• (c) not stored in the cache memory of the server computer and stored into the second local memory of the second client computer if said request for data indicates the data is exempt from being cached;
• wherein selecting the data that is to be exempt solely depend on an individual object basis, wherein the individual object includes choices of a page, a record, a field and a table;
• and
• said data which is designated as being exempt from being cached before it is retrieved is to be used only one time within a given time span, and said request by said application program indicates exempt data designation in a single operation.

In a cache controller for controlling a cache memory in a computer network, a method for selectively caching data objects in the computer network, comprising steps of:

• detecting a first read request generated by an application program running on a first client computer coupled to the computer network, wherein the first client computer includes a first local memory;
• detecting a second read request generated by the application program running on a second client computer coupled to the computer network, wherein the second client computer includes a second local memory, said first and said second read request indicating whether data object sought is exempt from being cached based on a predetermined data characteristic other than main memory address location of said particular data object;
• determining whether a requested data object is currently stored within the cache memory contained in a server computer coupled to the computer network;
• retrieving the requested data object from a cache memory of the server computer if the requested data object is currently stored within the cache memory;
• if the requested data object is not currently stored in the cache memory of the server computer:
• accepting the requested data read from a mass storage device coupled to the computer network;
• determining whether the requested data object is to be cached in the cache memory of the server computer based on said predetermined data characteristic of the data object:
• caching the requested data object in the cache memory of the server computer from said mass storage device if the requested data object has been designated to be cached;
• and
• if the requested data object has been designated not to be cached:
• (a) not caching the requested data object in the cache memory of the server computer;
• and
• (b) storing the requested data object in the first local memory of the first client computer or the second local memory of the second client;
• wherein selecting the data object that is to be exempt solely depend on an individual object basis, wherein the individual object includes choices of a page, a record, a field and a table;
• and
• said data object which is designated as being exempt from being cached before it is retrieved is to be used only one time within a given time span, and said request by said application program indicates exempt-data-object designation in a single operation.