oracle| problem
ORACLE interview Questions-Technical articles (2)
21. How to determine the time zone of the database?
Answer: SELECT dbtimezone from DUAL;
22. Explain the purpose of global_names set to True
Answer: Global_names indicates how the database is joined. If this argument is set to True,
You must connect the remote database with the same name when you create the database link
23. How do I encrypt the Pl/sql program?
Answer: WRAP
24. Interpretation of differences between function,procedure and package
Answer: Function and procedure are collections of Pl/sql code, usually in order to complete
a task. Procedure does not need to return any value and the function returns a value
On the other hand, package is a set of functions and Proceudre to complete a commercial function
The collection
25. Explain the purpose of the table function
Answer: The TABLE function returns a set of records by Pl/sql logic for
Normal table/view. They are also used for pipeline and ETL processes.
26.3 types of three advisory can be collected statistics
Solution: Buffer Cache Advice, Segment level Statistics, Timed Statistics
Which Oracle directory structure is Audit trace stored in?
Solution: Unix $ORACLE _home/rdbms/audit
Windows the Event Viewer
28. Explain the role of materialized views
Answer: Materialized views are used to reduce those totals, collections, and groupings of
The number of collections of information. They are typically suitable for data warehousing and DSS systems.
29. When the user process fails, which background process is responsible for cleaning it up
Answer: Pmon
30. Which background process refreshes materialized views?
Answer: The Job Queue processes.
31. How can you tell which session is being linked and what resources they are waiting for?
Answer: v$session/v$session_wait
32. Describe what is redo logs
Answer: Redo Logs is a physical and logical structure for storing database data changes.
can be used to repair the database.
33. How do I force log SWITCH?
Answer: ALTER SYSTEM SWITCH LOGFILE;
34. What are the two ways to determine DDL changes?
Answer: You can use Logminer or Streams
What did coalescing do?
Answer: coalescing for the tablespace of the dictionary management, the
The adjacent small extents are merged into a single large extent.
What is the difference between temporary tablespace and permanent tablespace?
Answer: A temporary tablespace is used for temporary objects such as sorting structures and permanent tablespaces
Used to store those ' real ' objects (such as tables, rollback segments, etc.)
37. Tablespace name created automatically when creating a database?
Answer: SYSTEM tablespace.
38. When you create a user, you need to give the new user what permissions to enable it to be linked to the database.
Answer: CONNECT
39. How to add data files to the tablespace?
Answer: ALTER tablespace <tablespace_name> ADD datafile <datafile_name> SIZE <size>
40. How to change the size of the data file?
Answer: ALTER DATABASE datafile <datafile_name> RESIZE <new_size>;
41. Which view is used to check the size of the data file?
Answer: Dba_data_files
42. Which view is used to judge the remaining space of tablespace
Answer: Dba_free_space
43. How can I tell who has added a record to the table?
Answer: Auditing
44. How do I refactor an index?
Answer: ALTER INDEX <index_name> REBUILD;
45. Explain what is partitioning (partition) and its advantages.
Answer: partition divides large tables and indexes into smaller, manageable partitions.
46. You have just compiled a pl/sql package but there are error reports, how to display error messages?
Answer: Show ERRORS
47. How to collect various state data of the table?
Answer: ANALYZE
The ANALYZE command.
48. How to start the session level trace
Answer: Dbms_session. Set_sql_trace
ALTER session SET sql_trace = TRUE;
Differences between the 2 tools of import and Sql*loader
Answer: These two Oracle tools are used to import data into the database.
The difference is that the import tool can only be processed by another Oracle tool export build
of data. and Sql*loader can import data sources in different ASCII formats.
50. 2 files for network connections?
Answer: TNSNAMES. ORA and Sqlnet. ORA
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