optdiag Input Mode

When you use the -i input_file syntax, optdiag reads the file as named and updates statistics in sysstatistics.

optdiag input mode changes the allow update to system tables configuration parameter by setting the parameter to 1 at the beginning of the session, and then to 0 at the end of the session.

During histogram input, the process checks these rules and displays error messages for any violated rules:
  • The step numbers must increase monotonically, unless the command includes the -T4 trace flag.

  • The column values for the steps must increase monotonically.

  • The weight for each cell must be between 0.0 and 1.0.

  • The total of weights for a column must be close to 1.0.

  • The first cell represents null values, and it must be present, even in columns that do not allow null values. There must be only one cell to represent the null value.

  • Two adjacent cells must not both use the < (less than) operator.