Techniques described herein can accelerate change data capture determinations such as stream reads, which show changes made to a table between two points in time. Three distinct row bitests that mark deleted, updated, inserted, rows in micro-partitions can be added as metadata for the table. These bitsets can be generated during DML operations and then stored as metadata of the new partition generated by the DML operations. The bitsets can then be used to generate streams showing the changes in the table between two points in time (changes interval).

Techniques for generating a dataflow graph include generating a first dataflow graph with a plurality of first nodes representing first computer operations in processing data, with at least one of the first computer operations being a declarative operation that specifies one or more characteristics of one or more results of processing of data, and transforming the first dataflow graph into a second dataflow graph for processing data in accordance with the first computer operations, the second dataflow graph including a plurality of second nodes representing second computer operations, with at least one of the second nodes representing one or more imperative operations that implement the logic specified by the declarative operation, where the one or more imperative operations are unrepresented by the first nodes in the first dataflow graph.

Described are methods, systems and computer readable media for performance logging of complex query operations.

A computer-implemented method for decomposing a decision table includes decomposing, by a computer processor, a decision table into a first sub-table and a second sub-table. The decision table includes two or more columns, and the decomposition is based on a semantic model describing relations among the two or more columns of the decision table. The first sub-table and the second sub-table together represent the decision table.

Described are methods, systems and computer readable media for data source refreshing.

Systems and methods for enabling construction of complex Boolean chemical substructure queries in a structured graphical user interface are provided. The chemical substructures (molecules) may be represented graphically in standard molecular notation, and may be arranged horizontally and vertically on the interface, along with Boolean logical operators. Boolean logical operators of a first type may logically associate molecules arranged in horizontal fashion to form row queries, whereas Boolean logical operators of a different, second type may logically associate the row queries to form a composite query to be applied to a database of molecules. The operators of the first type may comprise disjunctive operators, whereas the operators of the second type may comprise conjunctive operators.

There is provided a method of using a bitmap filter to filter a data source as part of a join operation. A set bit at a bit location of the bitmap filter is associated with an entry of the data source that comprises an identifier that matches a filter parameter. A row identifier of a row in another data source that corresponds to the identifier is determined based on a sum of a number of bits set in bit locations that are between the bit location of the set bit associated with the entry of the data source and a bit location in the bitmap filter corresponding to a different, known, row identifier of a different row in the another data source. The row of the another data source corresponding to the determined row identifier is interrogated to obtain information defining the identifier that matches the filter parameter.

Systems, methods, and devices for generating a secure join of database data are disclosed. A method creates a secure view of datapoints of a consumer account and processes, using a secure user defined function (UDF), the datapoints of the consumer account and datapoints of a provider account to generate a secure join key. The secure UDF returns a count of matching data points between the consumer account and the provider account, and the method provides the count of matching data points to the consumer account.

Techniques described herein can accelerate change data capture determinations such as stream reads, which show changes made to a table between two points in time. Three distinct row bitests that mark deleted, updated, inserted, rows in micro-partitions can be added as metadata for the table. These bitsets can be generated during DML operations and then stored as metadata of the new partition generated by the DML operations. The bitsets can then be used to generate streams showing the changes in the table between two points in time (changes interval).

A system and method of query processing in a multi-level storage system having a unified table architecture. A query is received by a common query execution engine connected with the unified table architecture, the query specifying a data record. The common query execution engine performs a look-up for the data record based on the query at the first level storage structure. If the data record is not present at the first level storage structure, the common query execution engine performs separate look-ups in each of the second level storage structure and the main store.