# The following SQL statement will convert a table A representing an m by n matrix
# in (i,j,value) format to a table with m rows and (n+1) columns, the first being the row id:
pivot A on j using max(value) order by i;

# To exclude the row id column:
select columns(* exclude (i)) from (pivot A on j using max(value)) order by i;

# To ensure the columns are presented in their natural order,
# the above 'select' statement may need to be adjusted.
# If n < 10, the following would suffice:
select columns(* exclude (i)) from (pivot A on j using max(value)) order by i;

# For 10 to 99 columns:
select columns('^[1-9]$'), columns('^[1-9][0-9]') from (pivot A on j using max(value)) order by i;

# If there are more than 99 columns, the above can be extended in the obvious way.