tailieunhanh - OCA /OCP Oracle Database 11g A ll-in-One Exam Guide- P17

OCA /OCP Oracle Database 11g A ll-in-One Exam Guide- P17:There is an ever increasing demand for staff with IT industry certification. The benefits to employers are significant—they can be certain that staff have a certain level of competence—and the benefits to the individuals, in terms of demand for their services, are equally great. Many employers are now requiring technical staff to have certifications, and many IT purchasers will not buy from firms that do not have certified staff. | OCA OCP Oracle Database 11g All-in-One Exam Guide 116 At any stage how does the instance find the files it needs and exactly what happens Start with NOMOUNT. When you issue a startup command Oracle will attempt to locate a parameter file using a systematic ordered search as depicted in Figure 3-8. There are three default filenames. On Unix they are ORACLE_HOME dbs ORACLE_HOME dbs ORACLE_HOME dbs and on Windows ORACLE_HOME database ORACLE_HOME database ORACLE_HOME database Figure 3-8 Sequential search for an instance parameter file during STARTUP Chapter 3 Instance Management 117 TIP spfileS is undoubtedly the most convenient file to use as your parameter file. Normally you will only use in a RAC environment where one file may be used to start several instances. You will generally only use an initS file if for some reason you need to make manual edits using a text editor spfiles are binary files and cannot be edited by hand. PART I In all cases SID refers to the name of the instance that the parameter file will start. The preceding order is important Oracle will work its way down the list using the first file it finds and ignoring the rest. If none of them exist the instance will not start. The only files used in NOMOUNT mode are the parameter file and the alert log. The parameters in the parameter file are used to build the SGA in memory and to start the background processes. Entries will be written out to the alert log describing this process. Where is the alert log In the location given by the BACKGROUND_DUMP_ DEST parameter that can be found in the parameter file or by running sho parameter background_dump_dest from a SQL Plus prompt once connected as a privileged user. If the alert log already exists it will be appended to. Otherwise it will be created. If any problems occur during this stage trace files may also be generated in the same location. EXAM TIP An init .