Chill With Searching and Loading

If you have 50,000,000 or more records contained in a variable and you want to look up the data from array by key and get a value similar to what you are looking for. What would you do?

Are you going to use untested code like this

<?php

$lotOfData = ['name' => 'I am stupid', ... , 'name' => 'Yes, I Am'];
$searchTerm = 'am';

foreach ( $lotOfData as $key => $value ) {
   if ( strpos($value, 'am') ) {
      return $value;
   } else {
      return "What ur looking for?!";
   }
}

Or using code like this?

<?php

function search( $array, $key, $value ) {
    $search = "/$value/i";
    $results = array_filter( $array, function( $a ) use( $search )  {
        unset( $a[$key] );
        return preg_grep( $search, $a );
    });
    return $results;
}

$lotOfData = ['name' => 'I am stupid', ... , 'name' => 'Yes, I Am'];
$searchTerm = 'am';

$search_result = search($lotOfData, 'name', $searchTerm);

Which code will you choose? If you have your own way to find similar data in arrays, please tell us how. It looks stupid, but YES that's ME. Spreading ignorance in orderly disorder.