sybase IQ index

Sybase IQ stores data very differently from conventional RDBMSs. A copy of the data is stored in a column-oriented format (instead of a row-oriented format, as in a conventional RDBMS).
The data values are indexed in arrays of bits for each column, called Bit-Wise indexes. The index either contains the distinct values if there are a few (up to 1,000), or it contains slices of values for larger numbers of distinct values. In both cases, these structures can be manipulated through simple binary operations. These Bit-Wise indexes can be applied to all types of data, for data element