关于oracle的timestamp with time zone的问题
在oracle的“Oracle® Database Globalization Support Guide”文档中
有关timestamp with timezone的描述让我无法理解。
Two TIMESTAMP WITH TIME ZONE values are considered identical if they represent the same instant in UTC, regardless of the TIME ZONE offsets stored in the data. For example, the following expressions have the same value:
TIMESTAMP '1999-01-15 8:00:00 -8:00'
TIMESTAMP '1999-01-15 11:00:00 -5:00'
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TIMESTAMP '1999-01-15 8:00:00 -8:00'
TIMESTAMP '1999-01-15 11:00:00 -5:00'
-----------
这两个数据的utc instance时间是多少?
TIMESTAMP '1999-01-15 8:00:00 -8:00'——》utc time"1999-01-15 0:00:00"
TIMESTAMP '1999-01-15 11:00:00 -5:00'——》utc time"1999-01-15 6:00:00"
还是其他?
怎么得出“the following expressions have the same value”这个结论的?