Abstract: In an exemplary embodiment of this disclosure, a method for loading data from a backup image of a database includes selecting a subset statement defining a subset of the data in the database. Tables of the database are identified based on metadata of the database. A target database is written having the structure but not the data of the identified tables. One or more table statements are constructed, by a computer processor, defining a subset of each identified table based on the subset statement. Selected data is unloaded from a backup image into the target database using respective table statements as filters.

Abstract: Disclosed is a computer-implemented method of compressing data in a columnar database comprising at least one column partitioned into a plurality of partitions including at least one empty partition and a plurality of filled partitions each comprising data entries associated with a set of parameters having parameter values relevant to the recurrence frequency of the data entry in the partition, the data entries being compressed in accordance with a compression dictionary based on the respective recurrence frequencies of the data entries in the filled partition.

Abstract: A method and system are provided for performance analysis of a database. The method includes receiving a proposed data model, generating a hypothetical query workload using a plurality of sample query templates representing different query constructs for the proposed data model, generating hypothetical optimizer statistics using predefined generating rules that include a projected cardinality for the proposed data model and creating a sample empty database and database schema using the proposed data model. The method also includes applying the hypothetical optimizer statistics to the sample empty database, based on generating the hypothetical optimizer statistics, applying each query construct of the hypothetical query workload to the database schema and estimating a cost of the hypothetical query workload for the proposed data model.

Abstract: In an exemplary embodiment of this disclosure, a method for loading data from a backup image of a database includes selecting a subset statement defining a subset of the data in the database. Tables of the database are identified based on metadata of the database. A target database is written having the structure but not the data of the identified tables. One or more table statements are constructed, by a computer processor, defining a subset of each identified table based on the subset statement. Selected data is unloaded from a backup image into the target database using respective table statements as filters.

Abstract: Dynamically identifying and preventing skewed partitions in a shared-nothing database is provided. The database management system software receives a parameter for identifying a threshold value associated with at least one distribution key value. Optimizer statistics are gathered on a first table that is distributed across one or more partitions in the shared-nothing database, wherein the first table includes a first table name. Distribution key skew is identified based on the gathered optimizer statistics indicating the threshold value being exceeded. A second table with an alternate distribution key, is created having a second table name for receiving overflow data rows associated with the at least one distribution key value based on the identified distribution key skew. A union all view is created based on the first and the second table.

Abstract: Dynamically identifying and preventing skewed partitions in a shared-nothing database is provided. The database management system software receives a parameter for identifying a threshold value associated with at least one distribution key value. Optimizer statistics are gathered on a first table that is distributed across one or more partitions in the shared-nothing database, wherein the first table includes a first table name. Distribution key skew is identified based on the gathered optimizer statistics indicating the threshold value being exceeded. A second table with an alternate distribution key, is created having a second table name for receiving overflow data rows associated with the at least one distribution key value based on the identified distribution key skew. A union all view is created based on the first and the second table.

Abstract: In an exemplary embodiment of this disclosure, a method for loading data from a backup image of a database includes selecting a subset statement defining a subset of the data in the database. Tables of the database are identified based on metadata of the database. A target database is written having the structure but not the data of the identified tables. One or more table statements are constructed, by a computer processor, defining a subset of each identified table based on the subset statement. Selected data is unloaded from a backup image into the target database using respective table statements as filters.

Abstract: Embodiments of the present invention provide a method, system and computer program product for test data generation using unique common factor sequencing. In an embodiment of the invention, a method for test data generation using unique common factor sequencing is provided. The method includes loading a table for population with test data in a test data generation tool executing in memory of a computer. A column set of multiple columns in the table associated with a key to the table can be selected for processing and different cardinality sequence values are assigned to the columns in the set such that the cardinality sequence values do not share a common factor except for unity as in the case of prime numbers.

Abstract: Embodiments of the present invention provide a method for test data generation using unique common factor sequencing. In an embodiment of the invention, a method for test data generation using unique common factor sequencing is provided. The method includes loading a table for population with test data in a test data generation tool executing in a memory of a computer. A column set of multiple columns in the table associated with a key to the table is selected for processing and different cardinality sequence values are assigned to the columns in the set such that the cardinality sequence values do not share a common factor except for unity as in the case of prime numbers.

Abstract: Embodiments of the present invention provide a system and computer program product for test data generation using unique common factor sequencing. In an embodiment of the invention, a computer program product for test data generation using unique common factor sequencing is provided. The computer program product includes loading a table for population with test data in a test data generation tool executing in a memory of a computer. A column set of multiple columns in the table associated with a key to the table is selected for processing and different cardinality sequence values are assigned to the columns in the set such that the cardinality sequence values do not share a common factor except for unity as in the case of prime numbers.

Abstract: Dynamically identifying and preventing skewed partitions in a shared-nothing database is provided. The database management system software receives a parameter for identifying a threshold value associated with at least one distribution key value. Optimizer statistics are gathered on a first table that is distributed across one or more partitions in the shared-nothing database, wherein the first table includes a first table name. Distribution key skew is identified based on the gathered optimizer statistics indicating the threshold value being exceeded. A second table with an alternate distribution key, is created having a second table name for receiving overflow data rows associated with the at least one distribution key value based on the identified distribution key skew. A union all view is created based on the first and the second table.

Abstract: Dynamically identifying and preventing skewed partitions in a shared-nothing database is provided. The database management system software receives a parameter for identifying a threshold value associated with at least one distribution key value. Optimizer statistics are gathered on a first table that is distributed across one or more partitions in the shared-nothing database, wherein the first table includes a first table name. Distribution key skew is identified based on the gathered optimizer statistics indicating the threshold value being exceeded. A second table with an alternate distribution key, is created having a second table name for receiving overflow data rows associated with the at least one distribution key value based on the identified distribution key skew. A union all view is created based on the first and the second table.

Abstract: In an exemplary embodiment of this disclosure, a method for loading data from a backup image of a database includes selecting a subset statement defining a subset of the data in the database. Tables of the database are identified based on metadata of the database. A target database is written having the structure but not the data of the identified tables. One or more table statements are constructed, by a computer processor, defining a subset of each identified table based on the subset statement. Selected data is unloaded from a backup image into the target database using respective table statements as filters.

Abstract: Embodiments of the present invention provide a system and computer program product for test data generation using unique common factor sequencing. In an embodiment of the invention, a computer program product for test data generation using unique common factor sequencing is provided. The computer program product includes loading a table for population with test data in a test data generation tool executing in memory of a computer. A column set of multiple columns in the table associated with a key to the table can be selected for processing and different cardinality sequence values are assigned to the columns in the set such that the cardinality sequence values do not share a common factor except for unity as in the case of prime numbers.

Abstract: Embodiments of the present invention provide a system and computer program product for test data generation using unique common factor sequencing. In an embodiment of the invention, a computer program product for test data generation using unique common factor sequencing is provided. The computer program product includes loading a table for population with test data in a test data generation tool executing in memory of a computer. A column set of multiple columns in the table associated with a key to the table can be selected for processing and different cardinality sequence values are assigned to the columns in the set such that the cardinality sequence values do not share a common factor except for unity as in the case of prime numbers.

Abstract: A method and system are provided for performance analysis of a database. The method includes receiving a proposed data model, generating a hypothetical query workload using a plurality of sample query templates representing different query constructs for the proposed data model, generating hypothetical optimizer statistics using predefined generating rules that include a projected cardinality for the proposed data model and creating a sample empty database and database schema using the proposed data model. The method also includes applying the hypothetical optimizer statistics to the sample empty database, based on generating the hypothetical optimizer statistics, applying each query construct of the hypothetical query workload to the database schema and estimating a cost of the hypothetical query workload for the proposed data model.

Abstract: Embodiments of the present invention provide a system and computer program product for test data generation using unique common factor sequencing. In an embodiment of the invention, a computer program product for test data generation using unique common factor sequencing is provided. The computer program product includes loading a table for population with test data in a test data generation tool executing in memory of a computer. A column set of multiple columns in the table associated with a key to the table is selected for processing and different cardinality sequence values are assigned to the columns in the set such that the cardinality sequence values do not share a common factor except for unity as in the case of prime numbers.

Abstract: Embodiments of the present invention provide a method for test data generation using unique common factor sequencing. In an embodiment of the invention, a method for test data generation using unique common factor sequencing is provided. The method includes loading a table for population with test data in a test data generation tool executing in memory of a computer. A column set of multiple columns in the table associated with a key to the table is selected for processing and different cardinality sequence values are assigned to the columns in the set such that the cardinality sequence values do not share a common factor except for unity as in the case of prime numbers.

Abstract: Embodiments of the present invention provide a method, system and computer program product for test data generation using unique common factor sequencing. In an embodiment of the invention, a method for test data generation using unique common factor sequencing is provided. The method includes loading a table for population with test data in a test data generation tool executing in memory of a computer. A column set of multiple columns in the table associated with a key to the table can be selected for processing and different cardinality sequence values are assigned to the columns in the set such that the cardinality sequence values do not share a common factor except for unity as in the case of prime numbers.

Abstract: Embodiments of the present invention provide a method, system and computer program product for test data generation using unique common factor sequencing. In an embodiment of the invention, a method for test data generation using unique common factor sequencing is provided. The method includes loading a table for population with test data in a test data generation tool executing in memory of a computer. A column set of multiple columns in the table associated with a key to the table can be selected for processing and different cardinality sequence values are assigned to the columns in the set such that the cardinality sequence values do not share a common factor except for unity as in the case of prime numbers. Thereafter, data is generated for the specified number of rows of each column in the column set according to a corresponding one of the cardinality sequence values and random data is additionally generated for other columns of the table without regard to any particular cardinality sequence value.