slow retrieval of BYTEA column - postgresql

Question

I'm supposed to be testing different methods to store PDF files in a Postgres Database using JDBC. Currently I'm trying it with BYTEA. Storing files works without problems, but the retrieval is super slow.
I am working with a couple files around 3MB each. Storing them takes around 3 seconds (total), so that's alright. But when I try to retreive them, it takes around 2 minutes between the output of how many files are in the DB and the program actually starting to create the files. Once it starts, it only takes around 5 seconds though to finish. Why is Postgres taking so long for the Query "SELECT file..." ? The query takes equally long when I use pgAdmin. Not retrieving the filesize doesn't change anything.
As far as I understand, the DB uses TOAST to split my files up and when I want to retrieve them, it hast to piece them back together first. But since splitting them (when uploading) only takes a couple seconds, putting them back together shouldn't take that long, right?
Here are some code snippets:
public void saveToDB(Files[] files) {
try (PreparedStatement s = con.prepareStatement("INSERT INTO fileTable (filename, file) VALUES (?,?)")) {
for (File f : files) {
System.out.println(f.getName()+" (" + f.length() / 1024 + "KB)");
s.setString(1, f.getName());
s.setBinaryStream(2, new FileInputStream(f), f.length());
s.executeUpdate();
}
con.commit();
}
}
public void getFromDB(File dir) {
dir.mkdirs();
try (Statement s = con.createStatement(); ResultSet rs = s.executeQuery("SELECT COUNT(*) FROM useByteA")) {
rs.next();
System.out.println("Files: " + rs.getInt(1));
}
try (Statement s = con.createStatement(); ResultSet rs = s.executeQuery("SELECT length(file), filename, file FROM fileTable")) {
while (rs.next()) {
System.out.println(rs.getString(2)+" (" + rs.getInt(1) / 1024 + "KB)");
File f = new File(dir, filename);
f.createNewFile();
try (FileOutputStream out = new FileOutputStream(f)) {
out.write(rs.getBytes(3));
out.flush();
}
}
}
}