Open a dictionary, go to the back find the index
You have all the keywords listed here alphabetically.
You can easily find each keywords show up at what page, which line number.
That inspire me to use it for omni search.
I need a such index table to collect all the possible keywords in all layers.
After each keywords, I have another 2 column, tells me this keyword show up at which layer and which field.
Just like dictionary index tell you this word appear at what page, what line number.
Now you can easily go to that page, count to line number to find that word.
Same idea in omni search, you can easily know which layer, what column to look for that keyword. Any that find that keyword in that layer, that column. The final result point or line has the keyword you looking for.
Omni search index table could looks like this:
keyword, layer name, column name
corona, all-in-one-project-layer, city name
98765431, all-in-one-project-layer, project ID
assembly 78, assembly_district_layer, assembly ID
riverside, counties-layer, county name
How to create such index table? This has to be done in Arcgis Pro in geodatabase, then upload as a table service to arcgis online or portal.