Method and apparatus for access, integration, and analysis of heterogeneous data sources via the manipulation of metadata objects

A computer-based method of accessing information in heterogeneous databases, the method comprising:

• presenting a graphical user interface with controls representing a data cart and a plurality of datasets;
• receiving user input that selects a dataset to add to the data cart from the plurality of datasets;
• generating a block information structure specifying the dataset;
• and
• adding the block information structure to the data cart.

A computer-based method of retrieving information represented by a blockset, the method comprising:

• for each of a plurality of blocks in the blockset in which each block specifies a subset of a dataset stored in a database, connecting to the corresponding database, wherein the blockset has a plurality of blocking variables, and the blocks each include a set of non-blocking variables, and specifying includes having a set of values for each blocking variable in the plurality of blocking variables;
• adding to a derived table a blocking column for each blocking variable in the set of blocking variables;
• adding to the derived table a non-blocking column for each element in a union of the non-blocking variables in the plurality of blocks;
• adding a row to the derived table including a cell for each column in the derived table, the row uniquely identified by a tuple of values from the sets of values for the blocking variables;
• and
• populating a cell of a non-blocking column in the row, using a value retrieved from the database corresponding to the block, wherein the block contains the non-blocking variable corresponding to the non-blocking column.

A computer-based method of collecting metadata for a dataset, the method comprising:

• prompting a user to provide a database name;
• confirming that the database name represents a database;
• displaying a list of tables in the database to the user;
• receiving user input specifying a table in the list of tables;
• prompting the user to confirm that a list of blocking variables and a list of non-blocking variables are correct for the database;
• prompting the user to confirm metadata for the dataset and for the list of non-blocking variables;
• if the user confirms the list of blocking variables, the list of non-blocking variables, and the metadata, adding a dataset corresponding to the table to a collection of datasets.

An article comprising a machine-readable storage medium that stores executable instructions to represent a subset of a dataset table of rows and columns, the instructions causing a machine to:

• select a set of blocking variables corresponding to blocking columns of the dataset table such that, for each row in the dataset table, a tuple of values for the blocking columns uniquely identifies the row within the dataset table;
• select a set of non-blocking variables corresponding to columns of the subset, the set of non-blocking variables disjoint from the set of blocking variables;
• and
• create a block information structure that includes the set of non-blocking variables and that includes, for each blocking variable in the set of blocking variables, a set of values.

An article comprising a machine-readable storage medium that stores executable instructions to represent a subset of a dataset table of rows and columns, the instructions causing a machine to:

• present a graphical user interface with controls representing a data cart and a plurality of datasets;
• receive user input that selects a dataset to add to the data cart from the plurality of datasets;
• generate a block information structure specifying the dataset;
• and
• add the block information structure to the data cart.