最近几年来,地理信息系统无论是在理论上还是应用上都处在一个飞速发展的阶段。 GIS被应用于多个领域的建模和决策支持,如城市管理、区划、环境整治等等,地理信息成为信息时代重要的组成部分之一; “数字地球”概念的提出,更进一步推动了作为其技术支撑的GIS的发展。 与此同时,一些学者致力于相关的理论研究,如空间感知、空间数据误差、空间关系的形式化等等。 这恰好说明了地理信息系统作为应用技术和学科的两个方面,并且这两个方面构成了相互促进的发展过程。
Memcached The The parameters are described as follows: In the following example, we use the Output information description: delete command is used to delete an existing key . 1.13.1. Syntax: ¶
delete basic syntax format of the command is as follows:delete key [noreply]
key :Key value key-value in the structure key used to find cached values noreply (optional): this parameter tells the server that there is no need to return data 1.13.2. Example ¶
runoob as key the expiration time is set to 900 seconds And then we use delete command to delete the``key`` .set runoob 0 900 9 memcached STORED get runoob VALUE runoob 0 9 memcached END delete runoob DELETED get runoob END delete runoob NOT_FOUND
1.13.3. Output ¶
DELETED :Deleted successfully. ERROR :Syntax error or deletion failed. NOT_FOUND : key doesn’t exist.