Using custom function in mutate() with dplyr & monetDB

Question

I am just beginning to discover all the advantages of using R & monetDB/monetDBLite package - great stuff!
I was curious however if it's possible to use a custom defined function in dplyr's mutate() i.e.

# Connect to monetDBLite
db <- src_monetdb(embedded = db.dir)
data <- tbl(db, "my.table")

# Try to make a new column using custom defined function  
data %>% group_by(colX) %>% mutate(NewCol = customFunc())  

Results in the following error:

Error in .local(conn, statement, ...) : 
Unable to execute statement 'SELECT colA colB colC...'.
Server says 'ParseException:SQLparser:SELECT: no such operator 'customFunc''.

It seems like the SQL parser has a problem finding the custom function. Am I overseeing something (declare R code in a SQL function definition etc.) ? Is it possible to use custom defined functions with the monetDBLite package like this?

Answer 1

Since @Hannes answered my question in the comments - i'm adding it here with some other stuff i picked up:

• one can use the basic dplyr verbs (select, filter, group_by & mutate) in conjunction with some other "basic" R functions. There is a list of the supported functions, and more on this, in the dplyr databases vignette under the section "SQL translation". So, using the example from my question above - one can do:
  data %>% group_by(col_x) %>% mutate(new_col = log10(some_old_col)).

• MonetDBLite does not support UDFs (e.g. my question here - if it's possible to use my UDF inside a mutate call) ...

• ... however the "full" MonetDB does support used defined functions to be sent to the db for computation. It is all well explained on their homepage.