$ORACLE_HOME/ctx/bin/ctxhx called during a select?

Hello,

This might seem like a weird question, but is $ORACLE_HOME/ctx/bin/ctxhx called during a select when using the contains clause?

For example: select score(1),  text_col from text_table where contains(text_col,'bla bla bla',1)>0

I was under the assumption that ctxhx was called during index creation or when a document was being converted to html or text.

Environment: Oracle EE 10.2.0.4 on Solaris x86-64

Thanks,

John