डाटाबेस र DBMS – Database & DBMS MCQ

डाटाबेस र DBMS: प्रश्न र उत्तर

सही लागेको विकल्पमा थिच्नुहोस्। सही भए हरियो, गलत भए रातो देखिन्छ; ३ सेकेन्डपछि सही उत्तर र व्याख्या देखिन्छ।

सही: ० / ०

441. In multiple-granularity locking, an 'IX' (intention-exclusive) lock on a table indicates that:

     कThe table is being dropped खThe whole table is locked exclusively गThe transaction intends to set exclusive locks on some rows within that table घNo other transaction may read any row of the table
     💬 टिप्पणी / गल्ती रिपोर्ट (०)

     छलफल / प्रश्न उत्तरमा गल्ती छ

     पठाउनुहोस्

     टिप्पणी जाँचपछि मात्र देखिन्छ।

442. Optimistic concurrency control (validation-based protocol) is most suitable when:

     कTransactions are very long and always conflict खConflicts between transactions are rare गThe system has no recovery log घAlmost all transactions update the same rows
     💬 टिप्पणी / गल्ती रिपोर्ट (०)

     छलफल / प्रश्न उत्तरमा गल्ती छ

     पठाउनुहोस्

     टिप्पणी जाँचपछि मात्र देखिन्छ।

443. In timestamp-ordering concurrency control, each transaction is given a timestamp:

     कWhen it starts, and conflicting operations are executed in timestamp order खOnly when it commits गOnly when a deadlock occurs घEqual to the number of locks it holds
     💬 टिप्पणी / गल्ती रिपोर्ट (०)

     छलफल / प्रश्न उत्तरमा गल्ती छ

     पठाउनुहोस्

     टिप्पणी जाँचपछि मात्र देखिन्छ।

444. Under strict two-phase locking (strict 2PL):

     कA transaction may acquire locks after releasing one खAll locks are released immediately after use गLocks are never needed for reading घExclusive locks are held until the transaction commits or aborts
     💬 टिप्पणी / गल्ती रिपोर्ट (०)

     छलफल / प्रश्न उत्तरमा गल्ती छ

     पठाउनुहोस्

     टिप्पणी जाँचपछि मात्र देखिन्छ।

445. When the failure of one transaction forces several other transactions that read its uncommitted data to roll back as well, this is called:

     कCheckpointing खLock escalation गCascading rollback घTwo-phase commit
     💬 टिप्पणी / गल्ती रिपोर्ट (०)

     छलफल / प्रश्न उत्तरमा गल्ती छ

     पठाउनुहोस्

     टिप्पणी जाँचपछि मात्र देखिन्छ।

446. Two transactions read the same balance and then both write updated values, so that the first update is overwritten by the second. This problem is called the:

     कDirty read problem खLost update problem गPhantom problem घDeadlock problem
     💬 टिप्पणी / गल्ती रिपोर्ट (०)

     छलफल / प्रश्न उत्तरमा गल्ती छ

     पठाउनुहोस्

     टिप्पणी जाँचपछि मात्र देखिन्छ।

447. After a transaction executes its final statement but before its changes are made permanent, it is in the:

     कPartially committed state खAborted state गActive state घFailed state
     💬 टिप्पणी / गल्ती रिपोर्ट (०)

     छलफल / प्रश्न उत्तरमा गल्ती छ

     पठाउनुहोस्

     टिप्पणी जाँचपछि मात्र देखिन्छ।

448. Deliberately adding redundancy to normalized tables to speed up read-heavy queries is called:

     कFragmentation खSerialization गDecomposition घDenormalization
     💬 टिप्पणी / गल्ती रिपोर्ट (०)

     छलफल / प्रश्न उत्तरमा गल्ती छ

     पठाउनुहोस्

     टिप्पणी जाँचपछि मात्र देखिन्छ।

449. Fifth Normal Form (5NF), also called Project-Join Normal Form, deals with:

     कPartial dependencies खTransitive dependencies गJoin dependencies घMultivalued dependencies only
     💬 टिप्पणी / गल्ती रिपोर्ट (०)

     छलफल / प्रश्न उत्तरमा गल्ती छ

     पठाउनुहोस्

     टिप्पणी जाँचपछि मात्र देखिन्छ।

450. A decomposition of R into R1 and R2 is lossless-join if:

     कEvery functional dependency appears in R1 खThe common attributes R1 ∩ R2 form a super key of R1 or of R2 गR1 and R2 have no attributes in common घR1 and R2 have the same number of attributes
     💬 टिप्पणी / गल्ती रिपोर्ट (०)

     छलफल / प्रश्न उत्तरमा गल्ती छ

     पठाउनुहोस्

     टिप्पणी जाँचपछि मात्र देखिन्छ।