Systems and methods for secure access of data

A non-transitory computer readable storage medium having stored thereon a computer executable program, which, when executed by a processor at a first computer system, causes the processor to perform a method comprising:

• receiving a query at the first computer system;
• using a portion of the received query to access non-sensitive data stored at a second computer system, remotely separated from the first computer system, which relates to a response to the received query;
• generating the response to the received query using the non-sensitive data accessed from the second computer system and using another portion of the received query to access sensitive data that is stored locally at the first computer system;
• and
• sending the response as a reply to the received query,
• wherein data stored in the first computer system and data stored in the second computer system collectively define a star schema, wherein one or more dimension tables of the star schema comprise data stored in the first computer system and a fact table of the star schema comprise data stored in the second computer system, and wherein the fact table includes a first column of surrogate values, wherein the first column of the fact table is associated with a first column in a first dimension table,
• wherein the first column in the first dimension table includes said surrogate values, the first dimension table comprising a second column comprising actual values corresponding to the surrogate values;
• wherein the received query is an SQL query specifying at least a first column in a first table stored in the first computer system and at least a second column in a second table stored on the second computer system, wherein accessing the non-sensitive data includes generating a derived SQL query specifying the one or more columns in the second table and one or more third columns in the first table.

A computer system comprising:

• one or more local computers, each local computer including a processor and a memory, the one or more local computers configured to:
• receive a query at the first computer system;
• use a portion of the received query to access non-sensitive data stored at a second computer system, remotely separated from the first computer system, which relates to a response to the received query;
• generate the response to the received query using the non-sensitive data accessed from the second computer system and using another portion of the received query to access sensitive data that is stored locally at the first computer system;
• and
• send the response as a reply to the received query,
• wherein data stored in the first computer system and data stored in the second computer system collectively define a star schema, wherein one or more dimension tables of the star schema comprise data stored in the first computer system and a fact table of the star schema comprise data stored in the second computer system, and
• wherein the fact table includes a first column of surrogate values, wherein the first column of the fact table is associated with a first column in a first dimension table, wherein the first column in the first dimension table includes said surrogate values, the first dimension table comprising a second column comprising actual values corresponding to the surrogate values;
• wherein the received query is an SQL query specifying at least a first column in a first table stored in the first computer system and at least a second column in a second table stored on the second computer system, wherein accessing the non-sensitive data includes generating a derived SQL query specifying the one or more columns in the second table and one or more third columns in the first table.