Computer systems and methods for reconciling data across data sources

A computer-implemented method for reconciling data across first and second data sources, the method comprising:

• accessing, with one or more database connectivity (DBC) drivers, the first and second data sources;
• storing, in local random access memory (RAM) of a data reconciliation computer system, data from each of the first and second data sources accessed by the one or more DBC drivers, wherein data from the first data source are stored in a first table in the RAM and data from the second data source are stored in a second table in the RAM, and wherein the RAM is local to a processor of the data reconciliation computer system;
• and
• comparing, by the processor that is in communication with the RAM, the data, wherein comparing the data comprises:
• unioning the first and second tables to form a unioned table, wherein the unioned table unions the data of the first and second tables and a set of primary keys of the first and second tables;
• identifying based on the unioned table the set of primary keys across the first and second tables, wherein the set of primary keys are a set of one or more columns in the both first and second tables that uniquely identify rows across both the first and second tables;
• comparing, in the unioned table, the data in the first and second tables, wherein comparing the first and second tables comprises:
• determining, based on the identified set of primary keys in the unioned table, a total number of mismatched cell values across the first and second tables, wherein determining the total number of mismatched cell values comprises:
• determining a total count of rows in each of the first and second tables, wherein the rows in the first and second tables are defined by the identified set of primary keys;
• determining a total count of rows in the first table that do not correspond to any row of the second table;
• determining a total count of rows of the second table that do not correspond to any row of the first table;
• determining a total count of rows that are common to both the first table and the second table;
• determining a total count of mismatched rows across the first and second tables;
• and
• determining the total number of mismatched cell values across the first and second tables by comparing cell values of the first table to cell values of the second table, wherein comparing the cell values of the first table to cell values of the second table comprises summing:
• a number of mismatched cell values across all of the mismatched rows;
• a number of cells in the first table that do not correspond to any row of the second table;
• and
• a number of cells in the second table that do not correspond to any row of the first table;
• and
• computing a score for the comparison of the first and second tables, wherein the score is computed based on the total number of mismatched cell values;
• and
• generating an electronic comparison report based on the comparing of the first table and second table.