[Oracle true 2 series] the initialization parameter is static & amp; Dynamic

[Oracle true 2 series] the initialization parameters are static and dynamic. When learning Oracle, we will find that many Oracle knowledge points are both in pairs. For ease of understanding and memory, I we will make a summary of this series. The first part of this series is: is the initialization parameter static or dynamic? In Oracle, spfile is introduced from 9i. Many parameters can be modified online, that is, the modifications will take effect immediately. The official documentation provides the following instructions: [plain] The ISSYS_MODIFIABLE column in V $ PARAMETER tells us whether the parameters are static or dynamic Static parameters require the instance to be restarted while dynamic parameters can take effect immediately upon being changed value: [plain] sys @ ORCL> select distinct issys_modifiable from v $ parameter; ISSYS_MOD --------- immediate false deferred parameter value description: ● FALSE: if issys_modifiable is changed to this value, the parameter is static. ● IMMEDIATE: indicates that the parameter is dynamic, can be modified online, and takes effect online. ● DEFERRED: this also indicates that the parameter is dynamic. However, the modification is invalid in the current session and takes effect only for the next session.