Abstract: According to embodiments of the present invention, methods, systems and computer-readable media are presented for accessing data within a database object, wherein an element of the database object is stored among a plurality of different storage regions with each storage region being associated with first and second range values indicating a value range for element values within that storage region. One or more element values within a storage region are identified residing outside a range of values of remaining elements within that storage region. Each identified element value is mapped to a second value. The first and second range values are determined for the storage region in accordance with the range of values of the remaining elements within that storage region. The storage region is scanned in accordance with a comparison of a requested value to at least one of the determined first and second range values of those storage regions.

Abstract: Each binary floating-point value in a set of binary floating-point values is converted to a decimal floating-point value. Data are determined including an exponent, a mantissa and a quantity of decimal digits of the mantissa for each decimal floating-point value. The exponents, the mantissas and the quantity of decimal digits are individually compressed to produce compressed floating-point values based on the individual compressions.

Abstract: According to one embodiment of the present invention, a system for compressing data determines a common divisor for a set of values comprising integers. The system divides each value within the set of values by the common divisor to produce reduced values, and represents the set of values in the form of data indicating the common divisor and the reduced values. Embodiments of the present invention further include a method and computer program product for compressing data in substantially the same manners described above.

Abstract: According to one embodiment of the present invention, a system for compressing data determines a common divisor for a set of values comprising integers. The system divides each value within the set of values by the common divisor to produce reduced values, and represents the set of values in the form of data indicating the common divisor and the reduced values. Embodiments of the present invention further include a method and computer program product for compressing data in substantially the same manners described above.

Abstract: Metadata for a plurality of database storage regions within memory are merged, where the metadata for each storage region comprises an interval including first and second interval values indicating a value range for values within that storage region. The first and second interval values are examined to identify overlapping storage regions and produce a sum of overlapped storage regions. The sum of overlapped storage regions is compared to a threshold and the metadata of the overlapped storage regions are merged based on the comparison.

Abstract: Methods, systems, and computer readable media of executing a database query are provided. One or more predicates are generated based on implicit filtering present within the database query, wherein each predicate specifies a condition with respect to a predicate value. An access path is selected for the database query based on the one or more predicates and the one or more predicates are integrated within the selected access plan. The database query is executed in accordance with the selected access plan. At least one predicate value based on data accessed is updated, as the database query is being executed, to increase filtering of data during remaining execution of the database query.

Abstract: Metadata for a plurality of database storage regions within memory are merged, where the metadata for each storage region comprises an interval including first and second interval values indicating a value range for values within that storage region. The first and second interval values are examined to identify overlapping storage regions and produce a sum of overlapped storage regions. The sum of overlapped storage regions is compared to a threshold and the metadata of the overlapped storage regions are merged based on the comparison.

Abstract: Storage regions in a database are associated with respective intervals including first and second interval values indicating a value range for values within that storage region. The first interval values are sorted into an order that determines a scanning order for a data operation on data in the storage regions. The storage regions are scanned in the scanning order to arrange data from the storage regions in at least a partially ordered sequence for the data operation.

Abstract: Storage regions in a database are associated with respective intervals including first and second interval values indicating a value range for values within that storage region. The first interval values are sorted into an order that determines a scanning order for a data operation on data in the storage regions. The storage regions are scanned in the scanning order to arrange data from the storage regions in at least a partially ordered sequence for the data operation.

Abstract: Methods, systems, and computer readable media of executing a database query are provided. One or more predicates are generated based on implicit filtering present within the database query, wherein each predicate specifies a condition with respect to a predicate value. An access path is selected for the database query based on the one or more predicates and the one or more predicates are integrated within the selected access plan. The database query is executed in accordance with the selected access plan. At least one predicate value based on data accessed is updated, as the database query is being executed, to increase filtering of data during remaining execution of the database query.

Abstract: For balanced partition placement in a distributed database, a first node in a set of nodes is identified, at an application executing using a processor and a memory, for a first primary partition of the distributed database, such that the primary partition and a first replica corresponding to the primary partition reside on different nodes in the set of nodes. A second node in the set of nodes is selected to place the first replica such that the second node does not include a second replica of a second primary partition, wherein the first primary partition and the second primary partition are co-resident on the first node. The first primary partition is placed on the first node and the first replica is placed on the second node.

Abstract: According to embodiments of the present invention, machines, systems, methods and computer program products for hierarchical compression of data are presented comprising creating a compression hierarchy of compression nodes, wherein each compression node is associated with a compression operation to produce compressed data. An output of any of the compression nodes may be compressed by another compression node or the same compression node. A path of one or more compression nodes is determined through said compression hierarchy based upon compression statistics to compress data, and the data is compressed by the compression nodes of the path. Various computational techniques are presented herein for manipulating the compression hierarchy to defer or reduce computation during query evaluation.

Abstract: According to one embodiment of the present invention, a system may execute database queries and may comprise a computer system including at least one processor. The system may select a column of a first table as a candidate column for creating a dictionary, create tokens for a foreign key in a second table that corresponds to a primary key in the first table, generate the dictionary for the selected column using the created tokens as indexes in the dictionary and modify a query accessing the column of the first table to retrieve column values based on the dictionary. Embodiments of the present invention further include a method and computer program product executing database queries in substantially the same manner described above.

Abstract: According to one embodiment of the present invention, a system may execute database queries and may comprise a computer system including at least one processor. The system may select a column of a first table as a candidate column for creating a dictionary, create tokens for a foreign key in a second table that corresponds to a primary key in the first table, generate the dictionary for the selected column using the created tokens as indexes in the dictionary and modify a query accessing the column of the first table to retrieve column values based on the dictionary. Embodiments of the present invention further include a method and computer program product executing database queries in substantially the same manner described above.

Abstract: To perform a join operation on database objects, data structures contained in a first database object are distributed across database partitions in accordance with a partitioning scheme. Data structures of the first database object are associated with respective indices computed complementarily to the partitioning scheme. Other indices are computed from the respective data structures of a second database object. The join operation is performed at each of the database partitions on the data structures in the respective first and second database objects having the indices and the other indices in common.

Abstract: To perform a join operation on database objects, data structures contained in a first database object are distributed across database partitions in accordance with a partitioning scheme. Data structures of the first database object are associated with respective indices computed complementarily to the partitioning scheme. Other indices are computed from the respective data structures of a second database object. The join operation is performed at each of the database partitions on the data structures in the respective first and second database objects having the indices and the other indices in common.

Abstract: Elements of a database object are stored among a plurality of different storage regions, each storage region being associated with a first value range indicating upper and lower range values for element values within that storage region. An index is generated and maintained for one or more second value ranges that include range values that comprise subsets of the first value ranges. A query is processed that includes a query value and one or more storage regions to be read is determined by using one of the index and the first value ranges based on the query value relative to a second value range.

Abstract: According to embodiments of the present invention, machines, systems, methods and computer program products for hierarchical compression of data are presented comprising creating a compression hierarchy of compression nodes, wherein each compression node is associated with a compression operation to produce compressed data. An output of any of the compression nodes may be compressed by another compression node or the same compression node. A path of one or more compression nodes is determined through said compression hierarchy based upon compression statistics to compress data, and the data is compressed by the compression nodes of the path. Various computational techniques are presented herein for manipulating the compression hierarchy to defer or reduce computation during query evaluation.

Abstract: According to embodiments of the present invention, machines, systems, methods and computer program products for hierarchical compression of data are presented comprising creating a compression hierarchy of compression nodes, wherein each compression node is associated with a compression operation to produce compressed data. An output of any of the compression nodes may be compressed by another compression node or the same compression node. A path of one or more compression nodes is determined through said compression hierarchy based upon compression statistics to compress data, and the data is compressed by the compression nodes of the path. Various computational techniques are presented herein for manipulating the compression hierarchy to defer or reduce computation during query evaluation.

Abstract: According to embodiments of the present invention, machines, systems, methods and computer program products for hierarchical compression of data are presented comprising creating a compression hierarchy of compression nodes, wherein each compression node is associated with a compression operation to produce compressed data. An output of any of the compression nodes may be compressed by another compression node or the same compression node. A path of one or more compression nodes is determined through said compression hierarchy based upon compression statistics to compress data, and the data is compressed by the compression nodes of the path. Various computational techniques are presented herein for manipulating the compression hierarchy to defer or reduce computation during query evaluation.