Determining quality of tier assignments

Abstract

Technologies pertaining to computing a tiering policy that defines how digital items are desirable stored across a plurality of different storage tiers are described herein. A data repository that comprises data that is indicative of historic user interaction with a search engine is accessed. Subsequently, a tiering policy for digital items that are retrievable by way of the search engine is computed based at least in part upon the data that is indicative of the historic user interaction with the search engine. Retrieval times for digital items in the data storage tiers differ across the data storage tiers.

What is claimed is: 
     
         1 . A method comprising:
 storing a search engine index across multiple storage tiers in accordance with a tier assignment policy, the multiple storage tiers comprise a first storage tier and a second storage tier, the first storage tier associated with a first access speed and the second storage tier associated with a second access speed that is slower than the first access speed, the tier assignment policy based upon observed user interaction with a search engine; and   executing a search over at least a portion of the search engine index in response to receipt of a query, wherein search results retrieved when executing the search over the search index are based upon the tier assignment policy.   
     
     
         2 . The method of  claim 1 , wherein executing the search over at least the portion of the search engine index comprises executing the search over at least the portion of the search engine index based upon a load of the search engine at a time of receipt of the query. 
     
     
         3 . The method of  claim 2 , further comprising updating the observed user interaction with the search engine with the query and the load of the search engine at the time of receipt of the query. 
     
     
         4 . The method of  claim 3 , further comprising:
 updating the tier assignment policy responsive to updating the observed user interaction with the search engine; and   storing the search engine index across the multiple storage tiers in response to updating the tier assignment policy.   
     
     
         5 . The method of  claim 1 , further comprising:
 determining the tier assignment policy based upon the observed user interaction with the search engine, the observed user interaction with the search engine comprises:   queries previously submitted to the search engine; and   tiers in the multiple storage tiers searched accessed by the search engine when searches were executed based upon the queries.   
     
     
         6 . The method of  claim 5 , wherein the observed user interaction with the search engine further comprises search results selected by users who issued the queries. 
     
     
         7 . The method of  claim 1 , further comprising determining the tier assignment policy based upon the observed user interaction with the search engine, the observed user interaction with the search engine comprises queries previously submitted to the search engine and respective loads of the search engine when the queries were submitted. 
     
     
         8 . The method of  claim 1 , further comprising determining the tier assignment policy based upon the observed user interaction with the search engine, the observed user interaction with the search engine comprises queries previously submitted to the search engine and respective weights assigned thereto, the weights are indicative of frequency of issuance of the queries. 
     
     
         9 . The method of  claim 1 , further comprising determining the tier assignment policy based upon the observed user interaction with the search engine, the observed user interaction with the search engine comprises values indicative of search result quality that respectively correspond to queries previously received at the search engine. 
     
     
         10 . A system comprising:
 at least one processor; and   memory that stores instructions that, when executed by the at least one processor, cause the at least one processor to perform acts comprising:
 receiving a query; and 
 executing a search over at least a portion of a search engine index in response to receipt of the query, the search engine index stored over multiple storage tiers of a tiered storage system in accordance with a tier assignment policy, the multiple storage tiers comprise data storage devices having different access speeds, the tier assignment policy defines which data storage devices store respective portions of the search engine index, and wherein executing the search comprises returning search results based upon the query and the tier assignment policy. 
   
     
     
         11 . The system of  claim 10 , wherein executing the search comprises searching over the portion of the search engine index based upon a computational load of the search engine at a time that the query is received. 
     
     
         12 . The system of  claim 10 , the data storage devices comprise different storage capacities. 
     
     
         13 . The system of  claim 10 , the portion of the search engine index is stored in a first data storage device having a first access speed, and wherein executing the search comprises:
 searching over the portion of the search engine index stored in the first data storage device in response to receipt of the query; and   refraining from searching over a second portion of the search engine index stored in a second data storage device based upon a load of the search engine a time that the query is received.   
     
     
         14 . The system of  claim 10 , wherein the tier assignment policy is based upon static rankings assigned to documents indexed by the search engine index. 
     
     
         15 . The system of  claim 10 , wherein the tier assignment policy is based upon numbers of words in documents indexed by the search engine index. 
     
     
         16 . The system of  claim 10 , wherein the tier assignment policy is based upon values that are indicative of qualities of tier assignments of documents that are indexed by the search engine index. 
     
     
         17 . A computer-readable data storage device comprising instructions that, when executed by a processor, cause the processor to perform acts comprising:
 storing a portion of a search engine index in a data storage device in a tiered data storage system, the data storage device has a first access speed, the tiered data storage system comprises the data storage device and a second data storage device that has a second access speed that is different from the first access speed, the second data storage device comprises a second portion of the search engine index, wherein the portion of the search engine index is stored in the data storage device based upon a tier assignment policy and the second portion of the search engine index is stored in the second data storage device based upon the tier assignment policy; and   executing a search over at least the portion of the search engine index in the data storage device in response to receipt of a query, wherein executing the search comprises returning search results based upon the query and the tier assignment policy.   
     
     
         18 . The computer-readable data storage device of  claim 17 , wherein the tier assignment policy is based upon loads observed at the search engine when queries were received by the search engine. 
     
     
         19 . The computer-readable data storage device of  claim 17 , the acts further comprising updating the tier assignment policy based upon the search results. 
     
     
         20 . The computer-readable data storage device of  claim 17 , wherein executing the search over at least the portion of the search engine index comprises searching over the portion of the search engine index in the data storage device while refraining from searching over the second portion of the search engine index in the second data storage device.