Question: ```
<table id="tab">
    <tr><td class="here">dgd</td><td class="here">dfg</td></tr>
    <tr><td class="here">fgf</td><td class="here">sg4</td></tr>
</table>

<table id="new">
    <tr><td id="al">sss</td></tr>
</table>

#tab td {
  padding: 5px;
  border: solid 1px red;
}

#new td {
    padding: 5px;
    height: 40px;
      border: solid 1px green;
    background-color: green;
}

#new {
    display: none;
}

$(".here").click(function(){
   $("#new").show();
})

    $("#al").click(function(){
       alert('ok');
    })

```

LIVE: <http://jsfiddle.net/HTHnK/>

How can i modify this example for add position in jQuery? I would like - if i click on .here then **table id = new** should show me on this clicked TD. Additionally if i clicked outside **table id = new** then this should hide.

How can i make it?

Answer: 
> 
> Will the first query be faster than the second one if there is no index on a column?
> 
> 
> 

In both cases the first on will basically always be faster. The `$where` clause will use the javascript engine. There can only be one javascript engine running per instance, so it may have to wait. Additionally, the `$where` clause will have to move objects into and out of the javascript VM which adds overhead and will be slower.

> 
> Also, is there any way to write query... `.find( { $where: "this.a / this.b > 3" } );` without using $where notation?
> 
> 
> 

The answer here is **no**. The query engine does not support any query where comparing data within an object. The only workarounds here are to:

1. Pre-compute the column (*which I'm sure you're trying to avoid*)
2. Run a `for` loop somewhere and do this "manually". This can be done with a Map/Reduce or a client-side query.

Of course, both solutions are sub-optimal. This is definitely a whole in MongoDB's functionality.
"Javascript executes more slowly than the native operators listed on this page, but is very flexible. See the server-side processing page for more information."

See the following for more details:
<http://www.mongodb.org/display/DOCS/Advanced+Queries#AdvancedQueries-JavascriptExpressionsand%7B%7B%24where%7D%7D>