How do Indexed Field Names originate?

[Craig_Eissler_Iceman]

I know how to recognize an Indexed Field Name by the the asterisk (*). And, I know how to add an Index to a field and remove it.

But, how do Indexed Field Names originate? In other words, how do they become indexed in the first place?

I ask because, I can have a Field that is indexed, but when I share that layer with someone else, it may not be indexed when they open it.

Thanks

[ChristopherCounsell]

https://doc.arcgis.com/en/arcgis-online/manage-data/manage-hosted-feature-layers.htm#ESRI_SECTION1_0...

You can create them or some other actions can create them e.g. search settings or filters.

I don't believe the fields are indexed by users. It may be because they are not the owner they don't see the * or something.

[Craig_Eissler_Iceman]

...Hmmm, I may be misunderstanding your response. Fields CAN absolutely be Indexed by a User using the "Add Attribute Index" tool. Users can also remove it using a tool. 

My question, however, is about Fields that become Indexed WITHOUT User involvement -- and, I'm referring to fields other than the 'ObjectID" field. 

It appears that some tools will automatically do this to certain fields as seen by the Output layer or table. ...That's what I don't quite understand. ...Does anybody know more bout this?

[ChristopherCounsell]

The link outlines how tools like filters and search apply an index on
fields.

My comment about users is that I don't believe other users accessing a
shared hosted feature later control over indexing.

[Craig_Eissler_Iceman]

Oh OK, thanks for the clarification.

Yeah, nothing I'm referring to is hosted online. 

[ChristopherCounsell]

https://pro.arcgis.com/en/pro-app/latest/help/data/geodatabases/overview/attribute-indexes-in-the-ge...

System fields are indexed. Different data formats will have different
system fields. What are you working with? How are you sharing it with other
users?
If you have a shape file and export it to file geodatabase I'd expect the
system fields to change.

[Craig_Eissler_Iceman]

I am taking a Standalone CSV Text file and Exporting it into a Geodatabase where it becomes a File Geodatabase Table ...During that process, one of the Fields became automatically Indexed. For some reason it indexes the 'Name' field which stores values for State names.

And, because of that, it will not Join correctly with the associated State spatial layer. ONLY the last record (Wyoming) joins; al other values are <Null>.

If I remove the Index it will work. But, I'm at a total loss as to the real "cause" and what is really going on here?

[ChristopherCounsell]

Name is a reserved word for databases. A bunch of words like 'delete' can
cause issues.

Can you change it to state_name?

[Craig_Eissler_Iceman]

...I've solved the problem, I'm just trying to figure out the exact "cause".

But, I wouldn't think a field named 'Name' would cause problems -- that field  name is used everywhere in GIS without problems.

I've also experienced this problem with a field named, 'GEOID".