In Computers, What Is a Subroutine?

A routine is a computer program that is a description of the processing objects and processing rules corresponding to a computing task. It is a dedicated program or part of the main program, and it can also consist of several subroutines. Configuration routines refer to routines in software systems or devices that deal with related issues, such as configuration assembly routines, fault routine diagnostic routines, input routines, and so on.

A configuration routine is a routine that configures a software system or device to handle related issues. Different software systems and equipment designs are generally different, so the steps for configuring the routines are also different. The purpose of configuration routines is to enhance the ability of systems and equipment to handle problems,

Configuration is a specification that defines the basic J2ME runtime environment, including a virtual machine and a set of core classes derived from J2SE. Each Configuration corresponds to a group of devices with similar capabilities. For example, a certain configuration may be defined as an embedded device with rich memory and network connection. The virtual machine may be a complete JVM, and the API may be a larger subset of the API in J2SE. Another configuration may be It is defined as a device with less memory and simple network connections. Its virtual machine may be a subset of the JVM, and its API may be a smallest subset of the APIs in J2SE plus a few other specific APIs.

Routines are computer programs or parts of them that can be used multiple times. The term program here refers to low-level language programs. Others see routines as synonyms for subroutines. The concept of routines has almost come with computer programs. Most programs need to output the results of their solution, and this is the routine. It is used to start the output device, send the data to the output device in its prescribed format, control, and supervise the output operation. As another example, users often check the program by prompting the execution order of instructions (commands), or by prompting the results, which can be done with trace routines. The most commonly used service routines are assembly routines, editing routines, input routines, fault routine diagnostic routines, and classification routines. A larger software system often consists of several routines. For example, the operating system can be composed of file management routines, resource management routines, job scheduling routines, input and output routines, clock management routines, synchronization exit routines, error analysis exit routines, etc. ^[1]

Configuration routine overview

The parameter file is a file that configures the entire Oracle database system. When the Oracle instance starts, it needs to read its configuration parameter values from the parameter file, and configure the instance memory structure and background process according to these values. For example: set the size of the SGA, determine the name and location of the database control file, whether to archive after the online redo day is filled. Therefore, the parameter file is very useful. If the parameter is not set properly, it may affect the performance of the entire Oracle database. We can adjust the oracle database by adjusting the parameter values in the parameter file to optimize the operating performance of the oracle database system.

Configuration routine parameters

A database parameter can be thought of as a "key = value" pair, such as a very important parameter DB_NAME, which is stored as

"DB_NAME = ORCL", the left DB_NAME of this store is the key, and "=" the right "ORCL" is the value. We can pass

"select * from v $ parameter" statement to get the parameter value of the current instance, or "show parameter parameter name" to get the value of a parameter.

Classification of configuration routine initialization parameters

According to different methods, initialization parameters can be divided into three categories: derivation parameters, operating system dependent parameters and variable parameters.

Derived parameters are usually derived from the calculation of other parameters and depend on other parameters. No modification is usually required.

The operating system depends on parameters, such as the db_cache_size parameter, to set the Oracle buffer cache memory size. This parameter size is limited by physical memory.

Variable parameters: Such parameters can often be adjusted to produce limits or performance changes.

According to the modification method, it can be divided into static parameters and dynamic parameters. Static parameters can only be modified in the parameter file and will take effect after restart. Dynamic parameters can be adjusted dynamically and will take effect after adjustment.

According to different acquisition methods, the initialization parameters can be divided into display parameters and implicit parameters. Display parameters can be queried by v $ parameter. Implicit parameters are usually switched by _, which can be obtained by querying the system table. There are no parameter entries in the initialization parameter file, but the ORACLE default value is used.