Just look up general best practices for persistent connections. My suggestions.

* By default, DO NOT
* If you have:
 * Dedicated web server and database hardware in production
 * and have tuned the web server and database correctly
 * and have an accurate production-like test environment
 * And still think your performance problems are caused by database connection time,

CONSIDER turning it on 

Persistent connections can cause

* Bugs because some connection state persisted unintentionally (this is a biggie!)
* Database connection limits to be exceeded
* Database performance to drop because of lots of ram used by the many (mostly idle) connections
* Bugs because connections have gone &quot;stale&quot; and the app didn&#39;t notice

But CAN

* Reduce latency on initial connection

If you think that connection latency is causing a problem, consider turning it on in your performance test system and *measuring* the impact.

I want to simulate a click on any link on a page using JavaScript. If that link has some function binded to its &#39;onclick&#39; event (by any other JS I don&#39;t have any control over), then that function must be called otherwise the link should behave in the normal manner and open a new page. 

I am not sure that just checking the value of the &#39;onclick&#39; handler would suffice. I want to build this so that it works on any link element. 

I have no control over what function maybe binded to the onclick event of the link using whichever JS library (not necessarily jQuery) or by simply using JavaScript.

EDIT: With the help of the answers below, it looks like it is possible to check for event handlers attached using jQuery or using the `onclick` attribute. How do I check for event handlers attached using `addEventListener` / any other JS library so that it is foolproof?

Simulating a click in jQuery/JavaScript on a link

What does it mean when you see things like:

    ?__utma=1.32168570.1258672608.1258672608.1259628772.2&amp;__utmb=1.4.10.1259628772&amp;

etc in the the url string?

Maybe it&#39;s simple, but I&#39;m thinking it&#39;s something I&#39;m not aware of because I see it every now and again.



What does __utma mean?

One of the parameters in the CodeIgniter database config is the following 

    [&#39;pconnect&#39;] TRUE/FALSE - Whether to use a persistent connection

    
What do you recommend I set this to?  
Is there a significant performance hit if I set it to FALSE?  
What potential problems might arise from setting it to TRUE?

Advantages / Disadvantages of pconnect option in CodeIgniter

One of the parameters in the CodeIgniter database config is the following
<pre><code class="hljs language-css">['pconnect'] TRUE/FALSE - Whether to use a persistent connection

</code></pre>
What do you recommend I set this to? 
Is there a significant performance hit if I set it to FALSE? 
What potential problems might arise from setting it to TRUE?

I get this error when I try to use autoload and namespaces:

&gt; **Fatal error:** Class &#39;Class1&#39; not found in **/usr/local/www/apache22/data/public/php5.3/test.php** on **line 10**

Can anyone tell me what I am doing wrong?

Here is my code:

Class1.php:

    &lt;?php
    
    namespace Person\Barnes\David
    {
        class Class1
        {
            public function __construct()
            {
                echo __CLASS__;
            }
        }
    }
    
    ?&gt;

test.php:

    &lt;?php
    
    function __autoload($class)
    {
        require $class . &#39;.php&#39;;
    }
    
    use Person\Barnes\David;
    
    $class = new Class1();
    
    ?&gt;

How do I use PHP namespaces with autoload?

I am running this DB call to get me multi-dimensional array
I am trying to get the keys of each but when I try it comes up blank or as array.   

    $root_array = array();
    $sites = $this-&gt;sites($member_id);
    foreach ($sites as $site){
        $records = $this-&gt;db-&gt;select(&#39;p.name as place_name, p.id as place_id,p.active as place_status&#39;)
                    -&gt;from(&#39;places p&#39;)
        	        -&gt;join(&#39;members_permissions pm&#39;,&#39;pm.sites_id = p.sites_id and pm.members_id =&#39;.$member_id)
        			-&gt;where(&#39;p.active&#39;, 0)
        			-&gt;get();
        
        $places = $records-&gt;result_array();
        $places[&#39;name&#39;] = $site[&#39;name&#39;];
        foreach($places as $place){
           $root_array[$site[&#39;name&#39;]][] = $place;
        }
        
    }
    return $root_array;

here is my php that loops through:

    &lt;?php foreach($places as $site): ?&gt;
        &lt;h5&gt;&lt;?=key($site)?&gt;&lt;/h5&gt;
            &lt;?php foreach($site as $place): ?&gt;
                &lt;h6&gt;&lt;?=$place[&#39;place_name&#39;]?&gt;&lt;/h6&gt;
            &lt;?php endforeach?&gt;
    
    &lt;?php endforeach ?&gt;

Also when I run a test which just spits out the array this is the result,
What I am trying to render is **[Philadelphia]**

    [Philadelphia] =&gt; Array
            (
                [0] =&gt; Array
                    (
                        [place_name] =&gt; XYX
                        [place_id] =&gt; 103200
                        [place_status] =&gt; 0
                    )
    
                [1] =&gt; Array
                    (
                    [place_name] =&gt; YYYY
                    [place_id] =&gt; 232323
                    [place_status] =&gt; 0
                )


PHP foreach loop key value

I have the following XML file, the file is rather large and i haven&#39;t been able to get simplexml to open and read the file so i&#39;m trying XMLReader with no success in php

    &lt;?xml version=&quot;1.0&quot; encoding=&quot;ISO-8859-1&quot;?&gt;
    &lt;products&gt;
    	&lt;last_updated&gt;2009-11-30 13:52:40&lt;/last_updated&gt;
    	&lt;product&gt;
    		&lt;element_1&gt;foo&lt;/element_1&gt;
    		&lt;element_2&gt;foo&lt;/element_2&gt;
    		&lt;element_3&gt;foo&lt;/element_3&gt;
    		&lt;element_4&gt;foo&lt;/element_4&gt;
    	&lt;/product&gt;
    	&lt;product&gt;
    		&lt;element_1&gt;bar&lt;/element_1&gt;
    		&lt;element_2&gt;bar&lt;/element_2&gt;
    		&lt;element_3&gt;bar&lt;/element_3&gt;
    		&lt;element_4&gt;bar&lt;/element_4&gt;
    	&lt;/product&gt;
    &lt;/products&gt;

I&#39;ve unfortunately not found a good tutorial on this for PHP and would love to see how I can get each element content to store in a database.

How to use XMLReader in PHP?

I&#39;m maintaining library written for PHP 5.2 and I&#39;d like to create PHP 5.3-namespaced version of it. However, I&#39;d also keep non-namespaced version up to date until PHP 5.3 becomes so old, that even Debian stable ships it ;)

I&#39;ve got rather clean code, about 80 classes following `Project_Directory_Filename` naming scheme (I&#39;d change them to `\Project\Directory\Filename` of course) and only few functions and constants (also prefixed with project name).

Question is: what&#39;s the best way to develop namespaced and non-namespaced versions in parallel?

* Should I just create fork in repository and keep merging changes between branches? Are there cases where backslash-sprinkled code becomes hard to merge?

* Should I write script that converts 5.2 version to 5.3 or vice-versa? Should I use PHP tokenizer? `sed`? C preprocessor?

* Is there a better way to use namespaces where available and keep backwards compatibility with older PHP?

----

*Update: [Decided against use of namespaces after all](http://pornel.net/phpns).*

Strategy for developing namespaced and non-namespaced versions of same PHP code

How would it be possible to generate a random, unique string using numbers and letters for use in a verify link? Like when you create an account on a website, and it sends you an email with a link, and you have to click that link in order to verify your account

How can I generate one of those using PHP?

How to generate a random, unique, alphanumeric string?

Is there going to be much benefit in indexing a boolean field in a database table?

Given a common situation, like &quot;soft-delete&quot; records which are flagged as inactive, and hence most queries include `WHERE deleted = 0`, would it help to have that field indexed on its own, or should it be combined with the other commonly-searched fields in a different index?

Indexing boolean fields

**Which providers are there and your experience using them**

I would like to know about all possible native .NET Framework Entity Framework providers that are out there as well as their limitations compared to the default *LINQ2Entities* (from MS for MS SQL). If there are more for the same database even better. Tell me and I&#39;ll be updating this post with this list.

Feel free to add additional providers directly into this post or provide an answer and others (including me) will add it to the list.

Entity Framework 1
--
**Microsoft SQL Server Standard/Enterprise/Express**

* Linq 2 Entities - Microsoft SQL Server connector
* [DataDirect ADO.NET Data Providers](http://www.datadirect.com/products/net/index.ssp)

**Microsoft SQL Server CE (Compact Edition)**

* Any provider?

**MySQL**

* [MySQL Connector](http://dev.mysql.com/downloads/connector/net) (since version 6.0) - I&#39;ve read about issues when using `Skip()`, `Take()` and `Sort()` in the same expression tree - everyone welcome to input their experience/knowledge regarding this.

  &gt; ***Note**: MySQL Connector/NET Visual Studio Integration is not supported in the Express Editions of Visual Studio, meaning you won&#39;t be able to view MySQL databases in the Database explorer window or add a MySQL data source via Visual Studio wizard dialog boxes.  Some users may find  that this limits their ability to use Entity Framework and MySQL within Visual Studio Express).*

* [Devart dotConnect for MySQL](http://www.devart.com/dotconnect/mysql/) - &lt;strike&gt;similar issues to MySql&#39;s connector as I&#39;ve read and both try to blame MS for it&lt;/strike&gt; *\[these issues are supposed to be [solved](https://stackoverflow.com/questions/1865352/1873609#1873609)\]*

**SQLite**

* [Devart dotConnect for SQLite](http://www.devart.com/dotconnect/sqlite/)
* [System.Data.SQLite](http://system.data.sqlite.org/)

**PostgreSQL**

* [Devart dotConnect for PostgreSQL](http://www.devart.com/dotconnect/postgresql/)
* [Npgsql](http://npgsql.projects.postgresql.org/)

**Oracle**

* [Devart dotConnect for Oracle](http://www.devart.com/dotconnect/oracle/)
* [Sample Entity Framework Provider for Oracle](http://code.msdn.microsoft.com/EFOracleProvider) - community effort project
* [DataDirect ADO.NET Data Providers](http://www.datadirect.com/products/net/index.ssp)

**DB2**

* IBM Data Server Provider [has EF support][1]. Here are some [limitations][2].
* [DataDirect ADO.NET Data Providers](http://www.datadirect.com/products/net/index.ssp)

**Sybase**

* [Sybase iAnywhere](http://www.sybase.com/detail?id=1060541)
* [DataDirect ADO.NET Data Providers](http://www.datadirect.com/products/net/index.ssp)

**Informix**

* IBM Data Server Provider [supports Informix](http://publib.boulder.ibm.com/infocenter/db2luw/v9r5/index.jsp?topic=/com.ibm.db2.luw.wn.doc/doc/c0051507.html)

**Firebird**

* [ADO.NET Data Provider with EF support][3]

**Provider Wrappers**

* [Tracing and Caching Providers for EF][4]

Entity Framework 4 (&lt;strike&gt;beta&lt;/strike&gt;)
--
**Microsoft SQL Server**

* Microsoft&#39;s Linq to Entities 4 - shipped with .net 4.0 and Visual Studio 2010; so far the only provider for EF4

**MySQL**

* [MySQL .NET connector](http://www.mysql.com/downloads/connector/net/), mostly functional but pending issues with CreateDatabase and DatabaseExists methods (v6.3.5)
* [Devart dotConnect for MySQL](http://www.devart.com/dotconnect/mysql/)

**SQLite**

* [Devart dotConnect for SQLite](http://www.devart.com/dotconnect/sqlite/)

**PostgreSQL**

* [Devart dotConnect for PostgreSQL](http://www.devart.com/dotconnect/postgresql/)

**Oracle**

* [Devart dotConnect for Oracle](http://www.devart.com/dotconnect/oracle/)

**Microsoft SQL Server Analysis Services (SSAS)**

* [SSAS Entity Framework Provider](http://agiledesignllc.com/Products.htm)


  [1]: http://publib.boulder.ibm.com/infocenter/db2luw/v9r5/index.jsp?topic=/com.ibm.db2.luw.apdv.ms.doc/doc/c0054118.html
  [2]: http://www.ibm.com/developerworks/wikis/display/DB2/IBM+Data+Server+LINQ+Entity+Framework+Limitations
  [3]: http://firebirdsql.org/index.php?op=files&amp;id=netprovider
  [4]: http://code.msdn.microsoft.com/EFProviderWrappers

A list of Entity Framework providers for various databases

When you study relational theory foreign keys are, of course, mandatory. But in practice, in every place I worked, table products and joins are always done by specifying the keys explicitly in the query, instead of relying on foreign keys in the DBMS.  

This way, you could of course join two tables by fields that are not meant to be foreign keys, having unexpected results.  

Why do you think that is? Shouldn&#39;t DBMSs enforce that Joins and Products be made only by foreign keys?


EDIT: Thanks for all the answers. It&#39;s clear to me now that the main reason for FKs is reference integrity. But if you design a DB, all relationships in the model (I.E. arrows in the ERD) become Foreign keys, at least in theory, whether or not you define them as such in your DBMS, they&#39;re semantically FKs. I can&#39;t imagine the need to join tables by fields that aren&#39;t FKs. __Can someone give an example that makes sense?__

PS: I&#39;m aware about the fact that N:M relationships become separate tables and not foreign keys, just omitted it for simplicity&#39;s sake.

Why are foreign keys more used in theory than in practice?

I can do SELECT TOP (200) ... but why not BOTTOM (200)?

Well not to get into philosophy what I mean is, how can I do the equivalent of TOP (200) but in reverse (from the bottom, like you&#39;d expect BOTTOM to do...)?

How to select bottom most rows?

I am creating a web app that will use OpenID logins and OAuth tokens with Youtube.  I am currently storing the OpenID identity and OAuth token/token secret in plain text in the database.

Is it inappropriate to store these values as plain text?  I could use a one-way encryption for the OpenID identifier but I don&#39;t know if that is necessary.  For the OAuth tokens, I would need to use a two-way encryption as my app relies on getting the session token for some uses.

Is it necessary to encrypt the OpenID identity?  Could someone use it to gain access to a user&#39;s account?

Securly Storing OpenID identifiers and OAuth tokens

I can sort a list  using Sort or OrderBy. Which one is faster? Are both working on same 
algorithm?

    List&lt;Person&gt; persons = new List&lt;Person&gt;();
    persons.Add(new Person(&quot;P005&quot;, &quot;Janson&quot;));
    persons.Add(new Person(&quot;P002&quot;, &quot;Aravind&quot;));
    persons.Add(new Person(&quot;P007&quot;, &quot;Kazhal&quot;));

1.

    persons.Sort((p1,p2)=&gt;string.Compare(p1.Name,p2.Name,true));
    
2.

    var query = persons.OrderBy(n =&gt; n.Name, new NameComparer());

    class NameComparer : IComparer&lt;string&gt;
    {
        public int Compare(string x,string y)
        {
          return  string.Compare(x, y, true);
        }
    }

C# Sort and OrderBy comparison

On December 1, 2009, Google announced support for &lt;a href=&quot;http://googlecode.blogspot.com/2009/12/google-analytics-launches-asynchronous.html&quot;&gt;asynchronous Google Analytics tracking&lt;/a&gt;.

The asynchronous tracking is achieved using the async directive for the `&lt;script&gt;` tag.

&lt;b&gt;Which browsers support the async directive (`&lt;script async=&quot;async&quot; /&gt;`) and since which version?&lt;/b&gt;

Which browsers support &lt;script async=&quot;async&quot; /&gt;?

Do you know if using double quotes instead of single quotes in ruby decreases performance in any meaningful way in ruby 1.8 and 1.9.

so if I type 

    question = &#39;my question&#39;

is it faster than 

    question = &quot;my question&quot;

I imagine that ruby tries to figure out if something needs to be evaluated when it encounters double quotes and probably spends some cycles doing just that.

Is there a performance gain in using single quotes vs double quotes in ruby?

&lt;a href=&quot;https://stackoverflow.com/questions/1310344/why-use-when-converting-int-to-bool&quot;&gt;Extends&lt;/a&gt;.

I thought I was being cool when I did something like:

&lt;pre&gt;
bool hasParent()
{
  return this-&amp;gt;parentNode ;
}
&lt;/pre&gt;

Even with a (bool) cast, the warning still doesn&#39;t go away.

Where this-&amp;gt;parentNode is NULL when there is no parent node.

But I&#39;m getting:

&lt;pre&gt;
warning C4800: &#39;Node *&#39; : forcing value to bool &#39;true&#39; or &#39;false&#39; (performance warning)
&lt;/pre&gt;

What&#39;s the deal, yo?  Why is that a performance warning?  I thought it&#39;d be more efficient to not write something like:

&lt;pre&gt;

bool hasParent()
{
  if( this-&amp;gt;parentNode )
    return true ;
  else
    return false ;
}
&lt;/pre&gt;

But the second version generates no warnings and the compiler seems a lot happier.  Which is faster though?

Why is there a performance warning on cast pointer to bool?

&gt; **Possible Duplicate:**  
&gt; [What is Big O notation? Do you use it?](https://stackoverflow.com/questions/133008/what-is-big-o-notation-do-you-use-it)  


Hi all,

fairly basic scalability notation question.

I recently recieved a comment on a post that my python ordered-list implimentation
&quot;but beware that your &#39;ordered set&#39; implementation is O(N) for insertions&quot;

Which is great to know, but I&#39;m not sure what this means.

I&#39;ve seen notation such as n(o) o(N), N(o-1) or N(o*o)

what does the above notation refer to?



what does O(N) mean

Are there any options to get the last insert id of a new record in CodeIgniter?

    $last_id = $this-&gt;db-&gt;insert(&#39;tablename&#39;,
        array(&#39;firstcolumn&#39; =&gt; &#39;value&#39;,
        &#39;secondcolumn&#39; =&gt; &#39;value&#39;)
    );

Considering the table consits of fields id (autoincrement) firstcolumn and secondcolumn.

This way you can use the insert id in the following code.


CodeIgniter activerecord, retrieve last insert id?

I have these URLs:

- http://backend.domain.com/system/setting/edit/12 
- http://backend.domain.com/product/edit/1

How to get controller name, action name from these URLs. I&#39;m CodeIgniter newbie. Are there any helper function to get this info

Ex:

```php
$params = helper_function( current_url() )
```

Where `$params` becomes something like 

```php
array (
  &#39;controller&#39; =&gt; &#39;system/settings&#39;, 
  &#39;action&#39; =&gt; &#39;edit&#39;, 
  &#39;...&#39;=&gt;&#39;...&#39;
)
```


CodeIgniter: How to get Controller, Action, URL information

I am working on my [REST client library for CodeIgniter][1] and I am struggling to work out how to send PUT and DELETE arguments in PHP.

In a few places I have seen people using the options:

    $this-&gt;option(CURLOPT_PUT, TRUE);
    $this-&gt;option(CURLOPT_POSTFIELDS, $params);

Annoyingly, this seems to do nothing. Is this the correct way to set PUT parameters?

If so, how do I set DELETE parameters?

*$this-&gt;option() is part of my library, it simply builds up an array of CURLOPT_XX constants and sends them to curl_setopt_array() when the built up cURL request is executed.* 

I am attempting to read PUT and DELETE parameters using the following code:

        	case &#39;put&#39;:
		    	// Set up out PUT variables
		    	parse_str(file_get_contents(&#39;php://input&#39;), $this-&gt;_put_args);
    		break;
    		
        	case &#39;delete&#39;:
		    	// Set up out PUT variables
		    	parse_str(file_get_contents(&#39;php://input&#39;), $this-&gt;_delete_args);
    		break;

There are two options here, I am approaching this in the wrong way or there is a bug somewhere in my libraries. If you could let me know if this should theoretically work I can just hammer away on debug until I solve it.

I dont want to waste any more time on an approach that is fundamentally wrong.

  [1]: http://github.com/philsturgeon/codeigniter-restclient

Handling PUT/DELETE arguments in PHP

Quick question.

Is there something similar to a **`phpinfo()`** - that would display the version for **`CodeIgniter`**?  

Thanks.

Which version of CodeIgniter am I currently using?

Can anyone assist in pointing me to a tutorial, library, etc. that will allow me to work with MongoDB from CodeIgniter?

Content Type	Original Author	Original Content on Stackoverflow
Question	Clayton	View Question on Stackoverflow
Solution 1 - Php	MarkR	View Answer on Stackoverflow

Advantages / Disadvantages of pconnect option in CodeIgniter

Php Problem Overview

Php Solutions

Solution 1 - Php

What does __utma mean?

Simulating a click in jQuery/JavaScript on a link

Attributions