Suppose that you join Tables A through E in a join index called ABCDE. If each table has two columns of data, expect the join index to have a total of fourteen columns. Sybase IQ creates an additional column, the ROWID column, for each of the joined tables except the top table. In this case, there are ten columns (two from each of the five tables), plus four ROWID columns.
You can use the NOTIFY option of the LOAD TABLE or INSERT statement to receive notification messages when you insert into a column index. These messages identify each column in a join index, including the ROWID column.
You can set the frequency of these messages with the NOTIFY_MODULUS option, and override the option value in either the CREATE DATABASE or LOAD TABLE command. For examples of these messages, see “Interpreting notification messages”.
Join index columns must have identical data type, precision, and scale.
