liquibase-core/src/main/java/liquibase/database/AbstractJdbcDatabase.java
@Override
    public int getMaxFractionalDigitsForTimestamp() {
        if (getConnection() == null) {
            // if no connection is there we cannot do anything...
            Scope.getCurrentScope().getLog(getClass()).warning(
                    LogType.LOG, "No database connection available - specified"
                            + " DATETIME/TIMESTAMP precision will be tried");
            return DEFAULT_MAX_TIMESTAMP_FRACTIONAL_DIGITS;
        }

        return DEFAULT_MAX_TIMESTAMP_FRACTIONAL_DIGITS;
    }
@Override
    public int getMaxFractionalDigitsForTimestamp() {
        if (getConnection() == null) {
            // if no connection is there we cannot do anything...
            Scope.getCurrentScope().getLog(getClass()).warning(
                    LogType.LOG, "No database connection available - specified"
                            + " DATETIME/TIMESTAMP precision will be tried");
            return DEFAULT_MAX_TIMESTAMP_FRACTIONAL_DIGITS;
        }

        return DEFAULT_MAX_TIMESTAMP_FRACTIONAL_DIGITS;
    }
Most relational databases support 9 fractional digits, and subclasses must overwrite this method if they
support less than that.

@return the maxmimum number of supported fractional digits in TIMESTAMP columns