1.5. Memcached set command

发布时间 : 2025-10-25 13:33:43 UTC      

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Memcached set command is used to use the value (data value) is stored in the specified key .

If set of key already exists, this command can update the key ,the corresponding original data, that is, to achieve the role of update.

1.5.1. Syntax:

The set basic syntax format of the command is as follows:

set key flags exptime bytes [noreply]
value

The parameters are described as follows:

  • key :Key value key-value in the structure key used to find cached values

  • flags :Can include integer parameters for key-value pairs, which clients use to store additional information about key-value pairs

  • exptime :Length of time to save key-value pairs in the cache (in seconds,0 means forever)

  • bytes :Number of bytes stored in the cache

  • noreply (optional): this parameter tells the server that there is no need to return data

  • value :The stored value (always in the second line) (which can be directly understood as key-value in the structure value )

1.5.2. Example

In the following example, we set:

  • Key → runoob

  • Flag → 0

  • Exptime → 900 (in seconds)

  • Bytes → 9 (bytes of data storage)

  • Value → memcached

set runoob 0 900 9
memcached
STORED

get runoob
VALUE runoob 0 9
memcached

END

1.5.3. Output

If the data setting is successful, the output:

STORED

Output information description:

  • STORED :Output after being saved successfully

  • ERROR :Output after a failed save

Principles, Technologies, and Methods of Geographic Information Systems

 102

In recent years, Geographic Information Systems (GIS) have undergone rapid development in both theoretical and practical dimensions. GIS has been widely applied for modeling and decision-making support across various fields such as urban management, regional planning, and environmental remediation, establishing geographic information as a vital component of the information era. The introduction of the “Digital Earth” concept has further accelerated the advancement of GIS, which serves as its technical foundation. Concurrently, scholars have been dedicated to theoretical research in areas like spatial cognition, spatial data uncertainty, and the formalization of spatial relationships. This reflects the dual nature of GIS as both an applied technology and an academic discipline, with the two aspects forming a mutually reinforcing cycle of progress.