4.0.0 (Prerelease)

v4 is a major release with many significant changes.

Simplified establishing a connection with a connection string.
All potentially blocking operations now require a context.Context. The non-context aware functions have been removed.
OIDs are hard-coded for known types. This saves the query on connection.
Context cancellations while network activity is in progress is now always fatal. Previously, it was sometimes recoverable. This led to increased complexity in pgx itself and in application code.
Go modules are required.
Errors are now implemented in the Go 1.13 style. Tests for specific error types must use As or Is.
Rows is now an interface.
The connection pool as been decoupled from pgx and is now a separate, included package (github.com/jackc/pgx/v4/pgxpool).
pgtype has been spun off to a separate package (github.com/jackc/pgtype).
pgproto3 has been spun off to a separate package (github.com/jackc/pgproto3).
Lower level PostgreSQL functionality is now implemented in a separate package (github.com/jackc/pgconn).
Replication support has been temporarily removed. It will be implemented in a separate package.
Tests are now configured with environment variables.