Is Chronicle the only way to reduce the size of my database?
Transactions on the database of a normal node will be regularly pruned, which keeps your database small. Only transactions that are still needed, as well as unspent outputs are kept in the database forever.
Chronicle, however, is a permanode implementation. Transactions of a permanode will not be pruned, so Chronicle is a way not to reduce your database size, but to increase it. However, if you need to have a full history of all transactions, running a Chronicle node is the only chance you can ensure this without having to rely on others running Chronicle nodes.