It allows you to create a second copy of the map, but where markers cannot be created, moved or deleted. This is ideal when you want to publish the map just for viewing.

Please note that due to limitations Notion put on embeds, you will not be able to copy the link, except after opening the map in a separate browser tab.

The reference is the database. As Notion does not provide (yet) ‘webhooks’, there is no way for the map to automatically update when a page is added or modified in the database. Either selecting ‘Refresh markers’ in the right-click menu, or refreshing the Notion page will draw all the markers.

On the other hand, when a marker is added, edited, duplicated or deleted from within the map, the Notion database is updated immediatly, and the changes are visible in the database within a couple of seconds.

Short answer: nowhere, except in a temporary cache, used to display read-only maps faster. We parse in memory your database to extract the information needed to generate the marker data, and have no other need of storing it.

Long answer, here is the detail of what we do store, solely in the European Union on servers operated by European companies:

• Occasionally, we may log error details, mainly to provide you better support if you contact us. All the logs are flushed automatically after 30 days.
• To quickly display the markers when the map is shown, a copy of the marker data is always cached on your device, using what is named ‘Web Storage’. But that is on your device.

There are no limits on the number of times you update a map.

• The text in the ‘Title’ property (all Notion databases have a ‘Title’ property) is used as the label of the marker.
• There must be two properties, named exactly ‘Lon’ and ‘Lat’ (first letter capitalised, the two others in lower case). Their type must be ‘Number’ or ‘Formula’ (a formula which returns a number). The values must represent the longitude and latitude of the marker in decimal degrees.
• The value of the first property of type ‘Url’, if any, is used for the links in the markers.
• The icon associated with the database page (aka row), if any, will be displayed as the marker. Otherwise, a default blue marker is used.
• The database can contain other properties, they are just ignored by geoNotion.

Five decimal places give a precision of roughly 1 meter, which is by far sufficient for any map.

This will occure if the type of the 'Lat' & 'Lon' properties is 'Formula', because you are calculating these values from some over property. geoNotion can in that case not update the values.

On geoNotion’s new map page, you must authorise a ‘Notion workspace’. Click on the ‘key’ button, and go through the authorisation process, selecting the page which contains your database.

Either the database does not exists anymore, or more likely, the page containing the database has not been authorised for geoNotion. Refer to error ‘A Notion workspace must be authorised’.

A list of all the missing requirements for the format of the database is displayed. Correct the database properties accordingly, and press the 'Reload' button in the 'About' menu option.