Technology for extensible in-memory computing

A system comprising:

• a processor;
• and
• a computer readable storage medium connected to the processor, where the computer readable storage medium has stored thereon a program for controlling the processor, and where the processor is operative with the program to execute the program for:
• receiving a user-defined function (UDF) in a central Computer System, and the central computer system causing registration of the UDF and distributing the UDF to a cluster of computer system nodes configured for performing, in volatile memory of the nodes, extract-transform-load processing of data cached in the volatile memory of the nodes;
• and
• receiving by the central Computer System first and second job specifications that specify the UDF, and the central computer system distributing instructions for the job specifications to the nodes, including at least one instruction that invokes the UDF for loading and executing the UDF in the volatile memory of at least one of the nodes during runtime of the job, where the central Computer System does not cause registration of the UDF again after receiving the first job specification.