TYPO3 - page IDs change when exporting and importing the pagetree with 'Export to .t3d' - v8

Question

I've created a pagetree like this:

[0]Site
|_[1]Root
..|_[3]Home
..|_[4]Company
..|_[2]Prices
..|_[5]Solutions
..|_[6]News
..|_[7]Contact
..[8]Footer //Folder
....|_[9]Impressum
....|_[10]Terms of Use
....|_[11]Sitemap

When I export it with 'Export to .t3d' and embed the data.t3d file into the initialisation folder of a distribution ... move it to the ext folder via ftp and activate it in the extension manager of another site (blank), the page IDs of the pages change:

[0]Site
|_[1]Root
..|_[11]Home
..|_[10]Company
..|_[9]Prices
..|_[8]Solutions
..|_[7]News
..|_[6]Contact
..[2]Footer //Folder
....|_[5]Impressum
....|_[4]Terms of Use
....|_[3]Sitemap   

When I do the same from the second to the third site (blank) ... the page IDs stay the same:

[0]Site
|_[1]Root
..|_[11]Home
..|_[10]Company
..|_[9]Prices
..|_[8]Solutions
..|_[7]News
..|_[6]Contact
..[2]Footer //Folder
....|_[5]Impressum
....|_[4]Terms of Use
....|_[3]Sitemap      

What logic does the 'Export to .t3d' follow for allocating the page IDs? And why do they not stay the same the first time? As a consequence I need to redefine my configuration setups ...

Answer 1

While importing you have an option force uids. This will use the same uids as the export is done. But that could destroy data on your importing installation if already data with those uids exist.

Therefore TYPO3 uses relocating on imports. Uids are adapted while imported to avoid collision or overwriting.

TYPO3 tries to identify all uids but sometimes (fields not clearly defines as page uids, usage in typoscript, ...) it fails and you need to adapt the uids by hand.

Be aware that force uids is used for all uids not only pages records.

If you import into a blank installation the pages are generated in order of occurence in the import. This will be the same order if you install an export of an once imported site (if you did not change pages meanwhile). Adding, deleting or moving pages in the second installation before the second export would result in changed uids in teh third installation while importing.