Database Access Using Partitioned Data Areas

Abstract

Provided are techniques that ensure efficient database accesses by partitioning. The techniques includes a partition generating unit which generates a value partition in which a unit subtree including target data to be partitioned is separated and registered according to the target data, and a base partition which includes an index for uniquely identifying the unit subtree, an XML parser which identifies positions of a start to and an end tag defining an attribute value of the structured document and generates a cutting position list Corresponding to the hierarchical structure of the attribute value for registration in a storage area, an XML cutting unit which identifies the start tag position and the end tag position of the unit subtree to be cut, and separates the unit subtree and its index from the structured document, and a cut-XML registration unit which registers the unit subtree and the index in the separate partitions.

We claim; 
     
         1 . An information processing apparatus, comprising:
 a processor;   a non-transitive storage area;   a database, stored in the non-transitive storage area, storing a plurality of stored values having a hierarchical structure., wherein the plurality of stored values represent data stored in a particular field of the database and wherein the stored, values do not represent addresses to data stored in the database;   a partition generating unit, executed on the processor, which generates a value partition, the value partition having a unit subtree, the unit subtree having target data of the plurality of stored values to be partitioned in the structured document separated and registered according to a stored value of the plurality of stored values of the target data, and generates a base partition which includes a second subtree distinct from the unit subtree and an index for uniquely identifying the unit subtree;   a parser unit, executed on the processor, which identifies positions of a start tag and an end tag, the start tag and the end tag defining a start value and an end value, the start, value and the end value each corresponding to a corresponding value of the plurality of stored values in the structured document, to generate a cutting position list corresponding to the hierarchical structure and register the cutting position list in a storage area;   a cutting unit, executed on the processor, which separates the unit subtree and the index for referring to the unit subtree from the structured document by referring to the cutting position list to identify the start tag position and the end tag position of the unit subtree to be cut, the unit subtree including the target data; and   a registration unit, executed on the processor, which registers the unit subtree and the index for identifying the unit subtree, separated by the cutting unit, in the value and base partitions.   
     
     
         2 . The information processing apparatus according to  claim 1 , wherein the unit subtree includes a plurality of the start tags, and the index is generated from a first one of the start tags in the unit subtree. 
     
     
         3 . The information processing apparatus according to  claim 2 , wherein the registration unit adds pointers to the unit subtree and the index for uniquely identifying the unit subtree to allow cross-reference between the unit subtree and the index, before registering the unit subtree and the index in the value and base partitions. 
     
     
         4 . The information processing apparatus according to  claim 3 , wherein in order to separate the unit subtree for registration in the value and base partitions by referring to the cutting position list, the cutting unit generates a subtree data list and registers the generated list in the storage area, the subtree data list including a range-defining pair in which a start position and an end position of the unit subtree included in the structured document are associated with each other and an occurrence counter in which the order of description of the unit subtree in the structured document is registered. 
     
     
         5 . The information processing apparatus according to  claim 4 , further comprising:
 an SQL processing unit which uses the target data to search for the unit subtree registered in the value partition; and   a search result generating unit which generates a result of the search performed by the SQL processing unit.   
     
     
         6 . The information processing apparatus according to  claim 4 , wherein the structured document is described in XML, and the database is an XMLDB which enables storage and search of XML documents. 
     
     
         7 . A database system, comprising;
 a database, stored in a non-transitory storage area, storing a plurality of stored values having a hierarchical structure, wherein the plurality of stored values represent data stored, in a particular field of the database and wherein the stored values do not represent addresses to data stored in the database;   a data management unit, executed on a processor, which generates and manages a value partition in which a unit subtree including target data of the plurality of stored values to be partitioned in the structured document is separated and registered according to a stored value of the plurality of stored values of the target data, and a base partition which includes a subtree other than the unit subtree and an index for uniquely identifying the unit subtree;   an SQL processing unit, executed on the processor, which processes a search request for searching the structured document registered in the database, the search request designating the hierarchical structure of the structured document; and   a search result generating unit, executed on the processor, which generates a search result with respect to the search request by using a result of individual search performed on the value partition by the SQL processing unit;   the data management unit including:
 a partition generating unit which generates the partitions; 
 a parser unit which identifies positions of a start tag and an end tag defining a start value and an end value, the start value and the end value each corresponding to a corresponding value of the plurality of stored values in the structured document, to generate a cutting position list corresponding to the hierarchical structure and register the cutting position list in a storage area; 
 a cutting unit which separates the unit subtree and the index for referring to the unit subtree from the structured document by referring to the cutting position list to identity the start tag position and the end tag position of the unit subtree to be cut the unit subtree including the target data; and 
 a registration unit which registers the unit subtree and the index for Identifying the unit subtree, separated by the cutting unit, in the separate partitions. 
   
     
     
         8 . The database system according to  claim 7 , wherein the unit subtree includes a plurality of start tags, and the index is generated from a first one of the start, tags in the unit subtree. 
     
     
         9 . The database system according to  claim 8 , wherein the registration unit adds pointers to the unit subtree and the index for uniquely identifying the unit, subtree to allow cross-reference between the unit subtree and the index, before registering the unit subtree and the index in the separate partitions. 
     
     
         10 . The database system according to  claim 9 , wherein in. order to separate the unit subtree for registration in the separate partition by referring to the cutting position list, the cutting unit generates a subtree data list and registers the generated list in the storage area, the subtree data list including a range-defining pair in which a start position and an end position of the unit subtree included in the structured document are associated with each other and an occurrence counter in which the order of description of the unit subtree in the structured document is registered. 
     
     
         11 . The database system according to  claim 10 , further comprising:
 an SQL processing unit which rises the target data to search for the unit subtree registered in the value partition; and   a search result generating unit which generates a result of the search performed by the SQL processing unit.   
     
     
         12 . The database system according to  claim 11 , wherein the structured document is described in XML, and the database is an XMLDB which enables storage and search of XML documents. 
     
     
         13 . A method having a database, the database including a structured document, the method comprising:
 separating target data into partitioned data based on a plurality of values associated with the target data, wherein the plurality of values represent data stored in a particular field of the database and wherein the stored values do not represent addresses to data stored in the database;   generating a value partition having a unit subtree, the unit subtree having the partitioned data therein;   generating a base partition, the base partition having a first subtree distinct from the unit subtree and an index associated with the unit subtree;   identifying positions of a start tag and an end tag associated with a start value and an end value, the start value and the end value each corresponding to a corresponding value of the plurality of stored values in the structured document;   generating a cutting position list corresponding to the hierarchical structure based on the start tag and the end tag;   storing the cutting position list in a storage area;   separating the unit subtree and. the index from the structured document based on the cutting position list to identify the start tag position and the end tag position of the unit subtree to be cut; and   registering the unit subtree and the index to identify the unit subtree, separated in the separating step, in the base and value partitions; searching the database based on at least one of the value partition and the base partition; and   displaying the results of the search.   
     
     
         14 . The information processing method according to  claim 13 , wherein the Index uniquely identifies the unit subtree and wherein the unit subtree includes a plurality of start tags, and generating the base and value partitions further includes the step of generating the index by identifying a first, one of the start tags in the unit subtree. 
     
     
         15 . The information processing method according to  claim 14 , wherein in order to separate the unit subtree for registration in the base and value partitions by referring to the cutting position list, separating the unit subtree and the index further includes generating a subtree data list and registering the generated subtree data list In the storage area, the subtree data list, including a range-defining pair in which a start position and an end position of the unit subtree included in the structured document are associated with each other and an occurrence counter in which the order of description of the unit subtree in the structured document is registered. 
     
     
         16 . The information processing method according to  claim 15 , wherein storing the cutting position list includes adding pointers to the unit subtree and the index for uniquely identifying the unit subtree to allow cross-reference between the unit subtree and the index, before registering the unit subtree and the index in the separate partitions. 
     
     
         17 . The information processing method, according to  claim 16  and further comprising:
 searching for the unit subtree registered in the value partition by using the target data; and 
 generating a search result by merging a result of individual search performed on the value partition in the searching step. 
 
     
     
         18 . A computer program product, the computer program product comprising;
 a computer readable storage medium having computer readable program code embodied therewith, the computer readable program code comprising computer readable program code configured to execute on a processor to:
 generate a value partition in which a unit subtree including target data stored in a database, to be partitioned in a structured document is separated and registered according to a plurality of values of the target data, wherein the plurality of values represent data stored in a particular filed of the database and wherein the stored values do not represent addresses to data stored in the database, and a base partition which includes a subtree other than the unit subtree and an index for uniquely identifying the unit subtree; 
 identify positions of a start tag and an end tag defining a start value and an end value, the start value and the end value each corresponding to a corresponding value of the plurality of stored values in the structured document to generate a cutting position list corresponding to a hierarchical structure of the plurality of values and register the cutting position list in a storage area; 
 separate the unit subtree and the index for referring to the unit subtree from the structured document by referring to the cutting position list to identify the start, tag position and the end tag position of the unit subtree to be cut, the unit subtree including the target data; and 
 register the unit subtree and the index for identifying the unit subtree, separated in the separating step, in the separate partitions. 
   
     
     
         19 . The computer program product according to  claim 18 , wherein the unit subtree includes a plurality of start tags, and generating the value and base partitions includes generating the index by identifying a first one of the start tags in the unit subtree. 
     
     
         20 . The computer program product according to  claim 19 , wherein in order to separate the unit subtree for registration in the separate partition by referring to the cutting position list, separating the unit subtree and index includes generating a subtree data list and registering the generated list in the storage area, the subtree data list including a range-defining pair in which a start position and an end position of the unit subtree included in the structured document are associated with each other and an occurrence counter in which the order of description of the unit subtree in the structured document is registered.