Add comments

conn.go

@@ -325,6 +325,7 @@ func (c *Conn) WaitForNotification(ctx context.Context) (*pgconn.Notification, e
 	return n, err
 }
 
+// IsClosed reports if the connection has been closed.
 func (c *Conn) IsClosed() bool {
 	return c.pgConn.IsClosed()
 }
@@ -358,6 +359,8 @@ func quoteIdentifier(s string) string {
 	return `"` + strings.ReplaceAll(s, `"`, `""`) + `"`
 }
 
+// Ping executes an empty sql statement against the *Conn
+// If the sql returns without error, the database Ping is considered successful, otherwise, the error is returned.
 func (c *Conn) Ping(ctx context.Context) error {
 	_, err := c.Exec(ctx, ";")
 	return err

pgxpool/tx.go

@@ -58,6 +58,13 @@ func (tx *Tx) LargeObjects() pgx.LargeObjects {
 	return tx.t.LargeObjects()
 }
 
+// Prepare creates a prepared statement with name and sql. If the name is empty,
+// an anonymous prepared statement will be used. sql can contain placeholders
+// for bound parameters. These placeholders are referenced positional as $1, $2, etc.
+//
+// Prepare is idempotent; i.e. it is safe to call Prepare multiple times with the same
+// name and sql arguments. This allows a code path to Prepare and Query/Exec without
+// concern for if the statement has already been prepared.
 func (tx *Tx) Prepare(ctx context.Context, name, sql string) (*pgconn.StatementDescription, error) {
 	return tx.t.Prepare(ctx, name, sql)
 }