This paper focuses on combining multiple databases into one shared database in a software system. This integration reduces repeated data, streamlines database management, simplifies front-end design, minimizes system size, and boosts database performance. They also introduced a transaction pool technique to enhance database processing efficiency by optimizing connections. The transaction pool manages database transactions, maximizes database speed while keeping connection numbers in check, reduces new connection creation, increases connection reuse, speeds up connection retrieval, and controls resource usage. Real-life examples in the paper show how transaction pools link individual databases to the shared one and explain creating non-visual transaction objects. The established method was practically implemented in an integrated software system.