有没有办法截断 CloudWatch 中的字段值?

Is there a way to truncate a field value in CloudWatch?

假设我有一个像这样的简单 Insights 查询

fields @timestamp, @message

有没有办法截断@message 字段。例如,假设我只想跳过前 50 个字符。

我知道我可以使用解析函数,但有没有更简单的方法,我可以在字段行中使用的等效子字符串

有一个substr函数:

Returns a substring from the index specified by the number argument to the end of the string. If the function has a second number argument, it contains the length of the substring to be retrieved. For example, substr("xyZfooxyZ",3, 3) returns "foo".

https://docs.aws.amazon.com/AmazonCloudWatch/latest/logs/CWL_QuerySyntax.html