Method and apparatus for cross-node sharing of cached dynamic SQL in a multiple relational database management system environment

摘要

The invention provides a data processing system, a method, computer program product and software for operating it where the data processing system includes a number of interconnected nodes. At least one data partition resides on one of the nodes, and one or more tables reside in a data partition. One of the nodes has a catalogue containing metadata describing tables and other objects and relationships therebetween in the data processing system. There is a global instruction cache at each node having a statement portion storing instruction statements and associated executables; each of the executable is designed for a particular environment; the instruction cache includes a dependency portion which lists objects and links them to the corresponding executable entries that depend on the objects; the instruction cache includes a shipped variation portion, each entry of the shipped variation portion refers to one executable entry and identifies the node from which the statement associated with the executable was originally shipped and the identification of such executable in the node from which it was originally shipped. The cache includes an invalidations in progress portion, each entry of the invalidations in progress portion refers to an object entry in the dependency portion.