Is there a performance difference between PDO fetch statements?

Question

like in

/* Exercise PDOStatement::fetch styles */
print("PDO::FETCH_ASSOC: ");
print("Return next row as an array indexed by column name\n");
$result = $sth->fetch(PDO::FETCH_ASSOC);
print_r($result);
print("\n");

print("PDO::FETCH_BOTH: ");
print("Return next row as an array indexed by both column name and number\n");
$result = $sth->fetch(PDO::FETCH_BOTH);
print_r($result);
print("\n");

print("PDO::FETCH_LAZY: ");
print("Return next row as an anonymous object with column names as properties\n");
$result = $sth->fetch(PDO::FETCH_LAZY);
print_r($result);
print("\n");

print("PDO::FETCH_OBJ: ");
print("Return next row as an anonymous object with column names as properties\n");
$result = $sth->fetch(PDO::FETCH_OBJ);
print $result->NAME;
print("\n");

Well the default are FETCH BOTH, I am wondering if FETCH ASSOC is faster when I'm going to fetch a lot of data; or they are the same?

Thanks

Answer 1

ASSOC, BOTH and OBJ are generally the same, except that they return a different structure. No performance differences there.

LAZY does some sort of lazy loading. PDO::FETCH_LAZY creates the object variable names as they are accessed. This means that you get the performance penalty only when you access the properties, not when calling fetch(). This is useful if you use only a part of the returned data.