[OSM-dev] Timestamp in PBF files

[Frederik Ramm]

Hi,

On 11/21/12 18:46, Jochen Topf wrote:
> On Tue, Nov 20, 2012 at 09:17:59PM -0600, Scott Crosby wrote:
>> How many nodes in the planet lack a latitude or longitude? Using a MAXINT
>> encoding will cost about 8 bytes for each missing latitude or longitude.
>>  It's possible to reduce this to 2-3 bytes, but the format gets
>> uglier/hackier. IMHO, probably not worth that cost.
>
> I just counted those cases. In the history dump from October 2012 there are
> 2344 nodes without coordinates. Hardly worth thinking about...

That sounds implausibly low.

Given that

1. every deleted node should be in that file without coordinates
2. we're currently at node id 2.03 billion,
3. there are 1.66 billion visible nodes in the database

we should have something like 370 million deleted nodes.

Hm, we probably have to remove from that number those nodes that were 
deleted in ancient times where we've meanwhile dropped the history, and 
maybe some from the first TIGER import where we manually removed them 
from the database, but still - at least every node deleted in the past 
couple of years *should* show up with visible=false in the full history 
dump, and any node with visible=false *should* not have coordinates.

Either there's an error in my thinking, or in your count, or in the 
script that does the history export ;)

Bye
Frederik


-- 
Frederik Ramm  ##  eMail frederik at remote.org  ##  N49°00'09" E008°23'33"