The use of lc and lemma_lc attributes can significantly increase the speed of various query operations. You can modify your corpus configuration files in order to include definitions of the lc and lemma_lc attributes. Both attributes can be calculated dynamically by including lines as follows:

ATTRIBUTE lc {
LABEL "word (lowercase)"
DYNAMIC utf8lowercase
DYNLIB internal
ARG1 "C"
FUNTYPE s
FROMATTR word
TYPE index
TRANSQUERY yes
}

ATTRIBUTE lemma_lc {
LABEL "lemma (lowercase)"
DYNAMIC utf8lowercase
DYNLIB internal
ARG1 "C"
FUNTYPE s
FROMATTR lemma
TYPE index
TRANSQUERY yes
}
To check that lc/lemma_lc is present in the corpus,  do a simple search for a word and click the info icon next to the frequency per million, labelled (3) in the screenshot. This will display the actual CQL used to execute the query.
  1. if the query uses word as the attribute, e.g. [word="(?i)calendar" | lemma="(?i)calendar"], lc/lemma_lc is not present
  2. if the query uses lc and lemma_lc, e.g. [lc="calendar"|lemma_lc="calendar"], lc/lemma_lc are present

description of the concordance search result screen