A sparse dataset structure is created by creating column vectors for one or more columns in a dataset that have at least one significant value. Each column vector includes data values for columns of the dataset. Each column vector that is a sparse column vector includes a look-up index array and a value array. Entries in the look-up index array represent columns. The value array includes values for a row in a column. Each entry in the value array points to a row entry in the look-up index array. A side structure includes a row index and a column index. The row index includes a location for an entry for each row where entries point to a location in the column index that identifies a column that has a first significant entry for a row. Alternatively a sparse dataset could be constructed with sparse rows.