Thread ID's changed, links to your site no longer work?

[Dirt Bike Addict]

According to Wayne Luke:

Why are my forums, threads, blogs, social groups, etc... renumbered? Or why does everything have new IDS?

Due to the new database structure of vBulletin 5 along with Channels and Nodes, the upgrade is actually doing a lot of importing from old tables into new tables. Since sites usually delete content, forums and so forth, there are usually gaps in the IDs of these items. During an Import these gaps are eliminated due to how MySQL and auto-numbering work.

So does this mean that any links to my site that are posted on another site, could be directed to the wrong thread as the thread ID number changed?

[Zachery]

Moving this here, as its feedback about the beta.

As far as I know this is correct. I know we're doing things to preserve redirects, I'm not sure how much of that is working at this time though.

[dethfire]

If redirects are not perfect, there is zero chance of established forums to upgrade. I'm not losing all my links in google and backlinks. This sounds really scary.

[Dirt Bike Addict]

As far as I know this is correct. I know we're doing things to preserve redirects, I'm not sure how much of that is working at this time though.

Wow, I'm speechless.

So I'm assuming internally posted thread links would also be affected? For example I post a link in this post to another thread on this forum.

[sadikb]

Right now they are doing 302 (temporary redirects). I am sure the bug will be fixed and they will implement 301 redirects in later builds.

[Hemanth]

IMO, they shouldn't use redirects at all. i.e. thread IDs and postids should be kept the same for upgrades.

[Zachery]

IMO, they shouldn't use redirects at all. i.e. thread IDs and postids should be kept the same for upgrades.

Its bad practice to force ids to be preserved when an import is done, which is really what a vB5 upgrade is.

[sadikb]

Its bad practice to force ids to be preserved when an import is done, which is really what a vB5 upgrade is.

Bad practice? Care explain? Zach, you are a great guy and I do not want to sound disrespectful, but it's no such thing as bad practice. Generally preserving ids will take more effort to code, but once done, it matters in no way whatsoever from a technical point of view. And I am an Oracle (and mostly every RDBMS) database professional, so I should know what I am talking about.

It's a stupid move, one done by someone who had either little migration experience or perhaps someone very short on time. "IF" the ids were preserved, someone could have coded an addon to rewrite urls to the old showthread.php etc method. Now you have entirely closed the possibility.

[Zachery]

In impex, our design goals were never to force ids into the system, it was seen as bad practice, I suspect its the same thing here. I'm just talking from experience with working with developers as to why its bad. I'm sorry I don't have more information.

[digitalpoint]

Its bad practice to force ids to be preserved when an import is done, which is really what a vB5 upgrade is.

Errrr... for the most part I agree with things you say, but this is absolutely not correct.

[Zachery]

Errrr... for the most part I agree with things you say, but this is absolutely not correct.

I am parroting things I've been told in the past, based on semi-reliable developer conversations.

If you can give me information as to why it shouldn't happen this way and we should preserve ids in some way, I can make an improvement request. I can't promise it will happen though.

[Joe D.]

All I know is in my test upgrade of my 4.2.0 form to VB5 I could still access all threads using their old URLs. If I couldn't I would have complained about it when I tried. I'm sure I've hard deleted threads and posts from my forum too so it's not like there were no skipped numbers.

[digitalpoint]

I am parroting things I've been told in the past, based on semi-reliable developer conversations.

If you can give me information as to why it shouldn't happen this way and we should preserve ids in some way, I can make an improvement request. I can't promise it will happen though.

Well, for one when you renumber everything, you need to keep a mapping of the old primary ID to the new primary ID. This means if you have 20M records (posts, threads, users, forums, etc.) you need a table that is kept forever that maps the new to the old (an extra 20M record table isn't a good thing).

This database map adds unnecessary DB queries (you have to look up the mapping before you can redirect).

Future upgrades/scalability... let's say vB6 does an upgrade by "importing" again... and again remapping keys... you need a table to store the oldest mapping as well as the new mapping, doubling the size of the mapping database and adding even more queries (first looking up the old map and then looking up the new map based on the first mapping lookup).

I'd certainly be interested to hear the benefits of remapping primary keys and why retaining primary keys is considered "bad practice".

[Zachery]

Okay,

So a quick run down, is that in order to transition the system into the new db schema the new key ids don't really match their old counter parts.
We had things like postid, threadid, blogid, groupid, socialgroupmesageid, pmid, forumid, etc. these can't be carried over 1:1 into the new schema because of the schema.
We keep these old ids mapped properly. So if someone comes in via showthread.php?t=X or p=Y or forumdispay.php?f=Z they get redirected to the proper item in the new system.


Am I making more sense now?

[dethfire]

We keep these old ids mapped properly. So if someone comes in via showthread.php?t=X or p=Y or forumdispay.php?f=Z they get redirected to the proper item in the new system.


Am I making more sense now?

All I care about is whether or not this will hurt google rankings and backlink juice