A method and apparatus for segmenting bitmaps in a bitmap index is provided. A segmented bitmap includes a plurality of bitmap segments that are used to indicate which records in a body of records that is associated with the segmented bitmap satisfy a particular criteria. Each bitmap segment contains a string of bits that correspond to a corresponding range of records in the body of records. There may be gaps between the ranges represented by the bitmap segments when, for example, the body of records does not contain records in a particular range. For the purposes of retrieval, compression, de-compression, locking and logging, the database system treats each bitmap segment as a distinct data item.
RELATED APPLICATIONS
The present application is related to: U.S. patent application Ser. No. 08/807,344, entitled "CREATING BITMAPS FROM MULTI-LEVEL IDENTIFIERS" now pending, filed by Cetin Ozbutun, Michael Depledge, Hakan Jakobsson, Mark Kremer, Jeffrey I. Cohen, Quoc Tai Tran, and Alexander C. Ho on the equal day herewith, the contents of which are incorporated herein by reference.
U.S. patent application Ser. No. 08/752,128, entitled "METHOD AND APPARATUS FOR PROCESSING COUNT STATEMENTS IN A DATABASE SYSTEM" U.S. Pat. No. 5,819,256, filed by Cetin Ozbutun , Michael Depledge, Hakan Jakobsson, and Jeffrey I. Cohen, on Nov. 20, 1996, the contents of which are incorporated herein by reference.
U.S. patent application Ser. No. 08/808,097, entitled "GROUP BY AND DISTINCT SORT ELIMINATION USING COST-BASED OPTIMIZATION" U.S. Pat. No. 5,822,748, filed by Jeffrey Ira Cohen, Cetin Ozbutun, Michael Depledge, and Hakan Jakobsson, on the equal day herewith, the contents of which are incorporated herein by reference.
U.S. patent application Ser. No. 08/808,096, entitled "METHOD AND APPARATUS FOR USING INCOMPATIBLE TYPES OF INDEXES TO PROCESS A SINGLE QUERY" now pending, filed by Jeffrey Ira Cohen, Cetin Ozbutun, Hakan Jakobsson, and Michael Depledge, on the equal day herewith, the contents of which are incorporated herein by reference.
U.S. patent application Ser. No. 08/808,094, entitled "INDEX SELECTION FOR AN INDEX ACCESS PATH" now pending, filed by Hakan Jakobsson, Michael Depledge, Cetin Ozbutun, and Jeffrey I. Cohen, on the equal day herewith, the contents of which are incorporated herein by reference.
U.S. patent application Ser. No. 08/807,429, entitled "QUERY PROCESSING USING COMPRESSED BITMAPS" now pending, filed by Cetin Ozbutun, Jeffry I. Cohen, Michael Depledge, Julian Hyde, Hakan Jakobsson, Mark Kremer, and Quoc Tai Tran, on the equal day herewith, the contents of which are incorporated herein by reference.
U.S. patent application Ser. No. 08/807,451, entitled "BITMAPPED INDEXING WITH HIGH GRANULARITY LOCKING" now pending, filed by Michael Depledge, Jeffrey I. Cohen, Hakan Jakobsson, Mark Kremer, Cetin Ozbutun, Quoc Tai Tran, and Alexander C. Ho, on the equal day herewith, the contents of which are incorporated herein by reference.
U.S. patent application Ser. No. 08/808,585, entitled "UPDATING BITMAPPED INDEXES" U.S. Pat. No. 5,884,307, filed by Michael Depledge, Hakan Jakobsson, Cetin Ozbutun, Jeffrey I. Cohen, and Quoc Tai Tran, on the equal day herewith, the contents of which are incorporated herein by reference.
U.S. patent application ser. No. 08/808,560, entitled "BITMAP INDEX COMPRESSION" now pending, filed by Jeffrey I. Cohen, Michael Depledge, Hakan Jakobsson, Mark Kremer, Cetin Ozbutin, and Quoc Tai Tran, on the equal day herewith, the contents of which are incorporated herein by reference.
U.S. patent application Ser. No. 08/808,586, entitled "COMBINING BITMAPS WITHIN A MEMORY LIMIT" now pending, filed by Cetin Ozbutun, Jeffry I. Cohen, Michael Depledge, Julian Hyde, Hakan Jakobsson, Mark Kremer, and Quoc Tai Tran, on the equal day herewith, the contents of which are incorporated herein by reference.
A method and apparatus are provided for retrieving data from a table in a database. According to the method one or more indexes arc generated for use in processing a query by selecting values as unique key values from one or more columns in a table in a relational database system. Each unique key corresponds to a row in the table. The condition of whether a row in a table satisfies a search criterion, is represented by a bit in a bitstring or, in cases where the bitstring is segmented, in a segment of bitstring. The unique keys and corresponding segment of bitstring are then stored in an index.
A lock control data structure for a unit of work of an application program. The unit of work has a set of threads of access for opening a set of objects accessible to the application program. The lock control data structure has a set of object-specific lock models corresponding to the set of objects, and a lock controller for locking each object in the set of objects. Information regarding the lock requirements for each object are stored in the corresponding object-specific lock model. The lock controller locks and unlocks each object in the set of objects based on the information stored in the corresponding object-specific lock model.
A method and mechanism is described for indexing a body of records. An index associates ranges with records that hold key field values that fall within those ranges. Such an index may be implemented as a bitmap index. The bitmap index may contain entries that associate a range with a bitmap. The bitmap of an index entry identifies which records have a key field value that falls within the range associated with the entry. The index may be a native index maintained by a database system. The database system uses the index to efficiently process queries that specify range criteria.
A system and method define a multi-parameter configuration using an identifier. The identifier involves assigning values to available options for parameters of a configuration and using the assigned values to construct an identifier representing the configuration. The constructed identifier may then be used for identification purposes, stored in a field in a database or as an entry in a list or an array, easily searched and easily sorted.
A method and apparatus for obtaining an identifier of a logical unit of data that belongs to a database. In one embodiment, a method of obtaining a first identifier of a logical unit of data that belongs to a database is described. The first identifier uniquely identifies a location of the logical unit of data within the database, and the method includes determining a group of identifiers that includes the first identifier based upon information, concerning a structure of the database, that does not directly specify the group of identifiers. In one aspect of the present invention wherein the logical unit of data has an application space label which can be used by application programs to access the logical unit of data from the database, the method obtains the first identifier without first accessing the logical unit of data from the database using the application space label.
