MongoDB

Safeness levels:

• Confirm change recorded in memory: [ 'w' => 1 ];

• Confirm inclusion in journal: [ 'j' => true ];

• Confirm committed to disk: [ 'fsync' => true ];

• Confirm replication: [ 'w' => 2 ];

<?php
$m = new Mongo();
$c = $m->demo->talks;

$c->insert(
    [ '_id' => 'mongodb' ],      // document
    [ 'w' => 1 ]                 // options
);
?>

Output