Use the following calculation to identify the size of primary table update:
Message overhead + 2 * Row size + 2 * Sum of length of column names + 8 * Number of columns ____________________________________ = Inbound message size of the update
Message overhead is 200 bytes. Each message includes a transaction ID, an origin queue ID, and other information.
Row size is the ASCII representation of the table columns (float or decimal columns are also presented in ASCII). For example, a CHAR(10) column has a size of 10 bytes. Multiply row width by 2 because both the before and after images of the row are distributed to replication sites.
Sum of length of column names is the sum of all the column name lengths in the table. Multiply this sum by 2.
When you set the value of the Suppress_col_names parameter
to Y and the value of the Use_repdef parameter
to Y, you can eliminate the sum of the length
of the column names and reduce the LTL by this amount.
Number of columns is the number of columns in the updated table. Multiply this number by 8.
Add the four numbers to obtain an estimate, in bytes, of the message size of the largest possible update.
For example, if you had a table with three columns of CHAR(10) each, and column names of 8 bytes each, the calculation is:
200 bytes + 2 * 30 bytes + 2 * 24 bytes + 8 * 3 ______________ = 332 bytes
