Comments on: Data portability and data serialization in WordPress

By: Cory

Cory — Wed, 13 Feb 2013 23:18:13 +0000

Hi Miriam,

Thanks for the detailed write-up on this topic!

I authored a plugin called WordPress Duplicator (http://wordpress.org/extend/plugins/duplicator/) and many times I have to educate users on the complexities of PHP serialization and its usually painful…

I stumbled across your article after looking for something to point user at as I was getting tired of trying to explain the subject. Kudos as this is exactly what I was looking for…

Trying to explain to users why a simple move is more complex than just moving files and a database is difficult when this topic enters the conversation. I’m just going to point them to this article

Thxs much!!

By: Data Serialization, WordPress, and my new best friend | WP Garage

Data Serialization, WordPress, and my new best friend | WP Garage — Thu, 03 May 2012 13:00:23 +0000

[...] my new best friend Rebecca Markowitz | May 3, 2012 | 0 Comments Recently, Miriam wrote about Data Serialization and what a pain in the tuchus(tush/bottom) it can be to migrate a site that has seralized links in [...]

By: Ryan Hellyer

Ryan Hellyer — Sat, 21 Apr 2012 19:55:51 +0000

The need to serialize data in WordPress is too ingrained to be stopped. Avoiding serialization now would be very problematic IMHO.

I don’t think the negatives are very great either. I can’t even think of any situations in which data portability would become a problem. I assumed people would be more concerned about performance and inability to query across specific bits of data.

By: Ryan Hellyer

Ryan Hellyer — Sat, 21 Apr 2012 19:50:53 +0000

I think that depends on what you are searching and replacing. Basic things like URLs should be fine I imagine.

By: HuangYeWuDeng

HuangYeWuDeng — Sun, 15 Apr 2012 09:25:35 +0000

It seems that data saved in your blog database was not in UNICDOE collection .My nick name just became ???? on your blog.
I’ve repost this article on my blog and put a link to your post.I hope this would be permitted.

By: ????

???? — Sun, 15 Apr 2012 09:23:22 +0000

great aritcle. I am a wordpress user for many years ,and I found that it’s impossible for a wordpresss blog to miagrate to another blog system without any data loose.

By: Dougal Campbell

Dougal Campbell — Fri, 13 Apr 2012 19:46:48 +0000

BTW, AFAIK, PHP is actually pretty resilient when it comes to changing the string lengths in serialized data. In actual usage, I think it will deserialize fine, even when the string length given doesn’t match the actual string. I have not tried a test yet, though.

By: Dougal Campbell

Dougal Campbell — Fri, 13 Apr 2012 19:23:25 +0000

In most cases, the auto serialization/deserialization of options doesn't matter much. If a plugin (or theme) has a good reason to need to store lots of data and select subsets of it, they should use separate table entries (with an identifiable prefix on the keys), or store the data in a different table. Calling serialized data in the database a "serious problem" is kind of overstating things. If the problem is data portability when changing domain names, that's just not a use-case worth optimizing for, because 99.9% of sites will not change their domain. If the problem is efficiency of selecting just certain portions of the data, it's up to the developer to know when to switch from serialized values to separate values.

By: Dougal Campbell

Dougal Campbell — Fri, 13 Apr 2012 19:16:32 +0000

Post meta is one of the places where it really doesn’t make much sense to serialize. One of the quirks of the post meta functions (which is sometimes a feature), is that you can store multiple entries, but with the same key. Then you can get all the values back as an array with just one get_post_meta() call. This can sometimes be useful.

The reason it’s done that way is that at the time I added the post meta functions to WP, the maybe_serialize() and maybe_unserialize() functions used by the options system weren’t in place yet.

By: Amaury

Amaury — Thu, 12 Apr 2012 15:29:18 +0000

For move/rename a WordPress network and manage seralized datas, i share a tools on github :
https://raw.github.com/herewithme/wordpress-cli-tools/master/move-wordpress-ms.php

Try it