Exam 1Z0-52

  1. Level 0 backup contains all used blocks.
  2. Level 1 backup  contains all blocks changed since level 0 or level 1 backup
  3. DBA command “alter database open” results in opening of online redo files and online datafiles.
  4. You can set the constraint to deferred state if you want to insert data into child table 1st and parent table later in the same transaction.
  5. Stopping the listener will not impact established sessions; Only new sessions will not be able to connect to database
  6. Multiple listeners can run on same host or server.
  7. Rows  in Global temporary table created with “ON COMMIT PRESERVE ROWS”  will stay for the life of session
  8. Frequent full checkpoints can cause degradation of database performance.
  9. Databases running archivelog support online backups.
  10. SPfile is binary file whereas pfile is text file
  11. Rows in Global temporary table created with “ON COMMIT DELETE ROWS” will stay for the life of transaction i.e. until you commit.
  12. DML locks are never acquired for data in temporary tables.
  13. Hierarchy of  database structures : OS Blocksè Oracle Data Blockè Extentsè Segmentsè Tablespace
  14. SGA_TARGET can be increased up to SGA_MAX_SIZE
  15. Initialization parameter REMOTE_AUTHENT_OS when set to FALSE ensures users cannot connect to database from remote machine by just logging  on to remote server
    1. Connection is possible if  database  authentication is performed
  16. Initialization parameter               LOG_BUFFER cannot be  dynamically modified for current instance
    1. Reboot is required if SPFILE/PFILE is modified for changes to take effect.
  17. Initialization parameter  DDL_LOCK_TIMEOUT
  18. Table locked in SHARED ROW EXCLUSIVE allows DML operation
  19. DRA does not support standby databases and RAC
  20. Changes to SPfile can be persistent across database restarts
  21. Buffer currently being accessed is called pinned buffer.
  22. DRA creates a manual checklist when a failure occurs because a datafile is accidently renamed or when a failure occurs because of bad  hardware connectivity
  23. Statistics can be locked to prevent overwriting of statistics.
  24. Datapump supports renaming of  tables during import
  25. Successful checkpoint during shutdown ensures all data is written to database files.
  26. Users cannot access data from offline tablespaces.
  27. Undo retention is not guaranteed if undo tablespace is of fixed size.
  28. Frequent update/inserts/deletes on tables with bitmap indexes cause performance issues because the smallest unit lock that can be acquired is bitmap segment.
  29. Multiple databases can be registered to single instance.
  30. SPfile resides on the database server only
  31. Exclusive locks are not required for conventional path SQL*loader
  32. Background process MMON is responsible for issuing alerts when thresholds are exceeded.
  33. Oracle supports creating indexes and views on temporary tables
  34. Enable validate  of  table defined as  initially immediate with  prevent  DML operations on table when the constraint is being enabled.
  35. Temporary tables are always created in temporary tablespace
  36. “ALTER TABLESPACE USERS OFFLINE” will result in checkpointing all datafiles belonging to database.
  37. Initialization parameter O7_DICTIONARY_ACCESSIBILITY used to restrict access to data dictionary objects.
  38. A datafile can belong to one tablespace.
  39. Leaf blocks in indexes are doubly linked
  40. If a row is deleted from table, It is logically deleted from index; however space is available for reuse.
  41. MMON transfers statistics from memory to disk at frequent intervals.
  42. oraInst.loc must be created manually before running  OUI in silent mode
  43. Value for LOG_CHECKPOINT_INTERVAL will override FAST_MTTR_TARGET settings
  44. Undo is required for flashback transaction, running reports requiring read consistency or to rollback a transaction.
  45. The number of private SQL areas is dependent on OPEN_CURSORS settings
  46. Local naming method uses tnsnames.ora file
  47. A extent cannot span datafiles
  48.  Enable validate of table defined as initially immediate with fail if existing rows violate the constraint.
  49. Ongoing transactions are rolled back  when the restarted after instance crash
  50. Undo retention is minimum time the committed undo data will be retained if there is free space.
  51. Static database  registration  for listener is required   if  DBA wants to connect to database remotely and start the database remotely
  52.  AWR is not generated if initialization parameter statistics_level is set to basic.

 

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