Some writer formats do indeed have an index column where you can define attribute indexes, but you'll have to do it manually (you can not do it e.g. using an attribute or a published parameter). Here's an example from the PostGIS writer:

Thanks David_r for your reply, though maybe I should have been a bit clearer. I want to be able to define attribute indexes specifically on an ESRI File Geodatabase Feature Class that is being generated using an FME Writer.

If you use the "Esri Geodatabase (File Geodb API)" writer you'll have that option.

It doesn't look like the "Esri Geodatabase (File Geodb ArcObjects)" allows you to define indexes the same way, but hopefully someone can prove me wrong.

I am pretty sure, you want believe me :-)

But try this:

The writer is for a

Esri Geodatabase (File Geodb)

FME 2017 Build 17650

CREATE INDEX I_IDX ON FeatureClass1 (Test)

CREATE Indexname ON Featureclass (Attribute)

OR

CREATE Indexname ON Featureclass (Attribute1,Attribute2,....)

Result:

I don’t know how or why it works…….

But it works!

Just to add a comment here. This solution posted here is now my Default solution to Creating FGDB indices. It is weird that an SQL command like "CREATE INDEX" works, but that will be in part because the FGDB API supports a subset of SQL commands.

As it creates the index AFTER writing the features, this is by far the fastest way to write to the Geodatabase. All other methods create the index before writing the features and with FGDBs this slows writing/updating down considerably.

Unfortunately it doesn't appear that "DROP INDEX" is supported in the API however.

Thanks for the bump and for confirming that it works, I've flagged the answer accordingly.