What SQL dialect is used for AGOL Feature Service definition queries?

[Bud]

@JustinH mentioned in 1:M Join to Pull feature with Specific Attribute information:

I pull all of the data from an AGOL Feature Service that our organization is hosting. 

What SQL dialect is used in SQL expressions on AGOL Feature Service data?

• Definition query
• Select by Attributes
• Any other SQL expressions in geoprocessing tools

[ChrisUnderwood · Accepted solution]

Hello @Bud , is "Standardized SQL" the answer you are looking for ?

https://doc.arcgis.com/en/arcgis-online/reference/sql-agol.htm

"ArcGIS Online requires developers to use standardized SQL queries when querying hosted feature layers."

[Bud]

Thanks @ChrisUnderwood.

What is meant by the word "workspace" in this context? Is a different AGOL FC/table considered to be a different workspace?

Standardized SQL functions in ArcGIS Online

Standardized queries are not supported on joins between different workspaces.

For example, are Table_1 and Table_2 different workspaces?