Hands-On Software Engineering with Golang

An overview of the DB schema for the CockroachDB implementation

Setting up the tables we need for the CockroachDB graph implementation is a fairly straightforward process. The following is a combined list of the SQL statements that will be applied when we run the included DB migrations:

CREATE TABLE IF NOT EXISTS links (
    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
    url STRING UNIQUE,
    retrieved_at TIMESTAMP
);

CREATE TABLE IF NOT EXISTS edges (
    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
    src UUID NOT NULL REFERENCES links(id) ON DELETE CASCADE,
    dst UUID NOT NULL REFERENCES links(id) ON DELETE CASCADE,
    updated_at TIMESTAMP,
    CONSTRAINT edge_links UNIQUE(src,dst)
);

You probably noticed that, while building the in-memory graph implementation, ...