71. Application of kernel parameters? SHMMAX mean: This setting does not decide how much physical memory is used in Oracle database or operating system, only determines the number of memory available. This setting does not affect the kernel resources of the operating system. Setting method: 0.5 * Physical memory example: SHMINFO_SHMMAX = 10485760 shmmin meaning: Shared memory minimum size. Setting method: Usually set to 1. Example: set shmsys: shminfo_shmmin = 1: SHMMNI meaning: The maximum number of memory segments in the system. Example: set shmsys: shminfo_shmmni = 100 shmseg Meaning: The number of maximum shared memory segments per user process can be used. Example: set shmsys: shminfo_shmseg = 20: semmni meaning: The maximum number of Semaphore Identifierer in the system. Setting method: Set the value of this variable to all Oracle's instances of all Oracle's instances of the processes to add 10. Example: Set Semsys: seminfo_semmni = 100 SemMns Emnity: The maximum number of EMAPHORES in the system. Setting method: This value can be calculated in the following manner: the sum of the value of the processes of each Oracle instance, the sum of the value (remove the largest processes parameter) the number of the maximum of the processes × 2 10 × Oracle instance. Example: Set Semsys: seminfo_semmns = 200 Semmsl: Meaning: The maximum number of Semaphore in a set. Setting method: Set the value of the largest processes in INITSID.ORA for 10 all Oracle instances. Example: set Semsys: seminfo_semmsl = -200
72. Which users have SYSDBA, SYSOPER? SQL> conn sys / change_on_install sql> select * from v_ $ pWFILE_USERS; 73. How to back up one or more tables separately? EXP user / password Tables = (Table 1, ..., Table 2) 74. How to back up one or more users separately? Exp System / Manager Owner = (User 1, User 2, ..., User N) File = Export File 75. How to retrieve the CLOB field full-text search? Select * from a where dbms_lob.instr (AA, 'K', 1, 1)> 0; 76. How to display the current connection user? Show user 77. How to view the path placed by the data file? Col File_Name Format A50 SQL> SELECT TABLESPACE_NAME , file_id, bytes / 1024/1024, file_name from dba_data_files order by file_id; 78. how to view the existing rollback segments and their status SQL> col segment format a30 SQL> SELECT SEGMENT_NAME, OWNER, TABLESPACE_NAME, SEGMENT_ID, fILE_ID, sTATUS fROM? DBA_ROLLBACK_SEGS79. How to change the CHECK range initially defined by a field? SQL> ALTER TABLE XXX DROP CONSTRAINT CONSTRAINT_NAME; then create a new constraint again: SQL> ALTER TABLE XXX Add constraint constraint_name check (); 80. What are the Oracle common system files? Display these files from the following view: V $ DATABASE, V $ DATAFILE, V $ logfile v $ ControlFile V $ Parameter;
