databases Online Quiz - 177
| Description: databases Online Quiz - 177 | |
| Number of Questions: 20 | |
| Created by: Aliensbrain Bot | |
| Tags: databases |
Which one is not the output of the LOAD utility
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Loaded table or partition
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Discard file of rejected records
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Summary report of errors encountered
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Updated system catalog table stats
To answer this question, the user needs to be familiar with the LOAD utility in database systems.
The LOAD utility is used to load data from external files into database tables. It is commonly used for bulk inserts of large amounts of data.
Now, let's go through each option to determine which one is not an output of the LOAD utility:
A. Loaded table or partition: This is a valid output of the LOAD utility. When the LOAD utility is successful, it loads data from external files into database tables or partitions.
B. Discard file of rejected records: This is a valid output of the LOAD utility. When the LOAD utility encounters records that cannot be loaded into the target table or partition, it writes those records to a discard file.
C. Summary report of errors encountered: This is a valid output of the LOAD utility. When the LOAD utility encounters errors while loading data, it generates a summary report of those errors.
D. Updated system catalog table stats: This is not an output of the LOAD utility. The LOAD utility is used for inserting data into tables, not updating system catalog table stats. The job of updating system catalog statistics falls under the responsibility of the database management system.
Therefore, the answer is:
The Answer is: D
Which utility is used to insert bulk amount of data in to a table.
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LOAD
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UNLOAD
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INSERT
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RUNSTATS
AI Explanation
To answer this question, you need to understand the concept of inserting data into a table.
Option A) LOAD - This option is correct because the LOAD utility is used to insert a bulk amount of data into a table. The LOAD utility is typically used for loading large amounts of data efficiently and quickly.
Option B) UNLOAD - This option is incorrect. The UNLOAD utility is used to extract data from a table and create a data file.
Option C) INSERT - This option is incorrect. The INSERT statement is used to insert individual rows of data into a table, not a bulk amount of data.
Option D) RUNSTATS - This option is incorrect. The RUNSTATS utility is used to collect statistics about tables and indexes, but it is not used for inserting data.
The correct answer is A) LOAD. This option is correct because the LOAD utility is used to insert a bulk amount of data into a table.
Which utility is used to reclaim fragmented space
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LOAD
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UNLOAD
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REORG
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RUNSTATS
AI Explanation
To answer this question, you need to understand the concept of fragmented space and the utility used to reclaim it.
Fragmented space refers to the scattered or unused space within a database or storage system. This can occur when records or data are deleted or modified, leaving gaps or unused space. Reclaiming fragmented space involves consolidating or rearranging the data to optimize the storage.
The utility used to reclaim fragmented space is the REORG utility.
Option A) LOAD - The LOAD utility is used to load data into a database. It does not specifically address the reclamation of fragmented space.
Option B) UNLOAD - The UNLOAD utility is used to extract data from a database. It does not address the reclamation of fragmented space.
Option C) REORG - The REORG utility is used to reorganize data in a database, including the reclamation of fragmented space. This utility helps to improve performance and optimize storage.
Option D) RUNSTATS - The RUNSTATS utility is used to collect statistics about the data in a database. It does not specifically address the reclamation of fragmented space.
The correct answer is C) REORG. This option is correct because the REORG utility is used to reclaim fragmented space by reorganizing and optimizing the data in a database.
Which utility is used to update the data related to tablespaces & indexes in system catalog tables
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LOAD
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UNLOAD
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REORG
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RUNSTATS
AI Explanation
To answer this question, you need to understand the utilities used to update data related to tablespaces and indexes in system catalog tables.
Option A) LOAD - The LOAD utility is used to load data into a table from an input file, but it does not update data related to tablespaces and indexes in system catalog tables.
Option B) UNLOAD - The UNLOAD utility is used to unload data from a table into an output file, but it does not update data related to tablespaces and indexes in system catalog tables.
Option C) REORG - The REORG utility is used to reorganize the data and indexes of a table to improve performance, but it does not update data related to tablespaces and indexes in system catalog tables.
Option D) RUNSTATS - The correct answer is D. The RUNSTATS utility is used to update the statistics of tables and indexes in system catalog tables. These statistics are used by the query optimizer to generate efficient access plans for SQL queries.
Therefore, the correct answer is D) RUNSTATS.
Which one is the correct option for taking unload from the table EMPTAB
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UNLOAD TABLE DSN1DB04.EMPTABSP
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UNLOAD TABLESPACE DSN1DB04.EMPTABSP
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UNLOAD DATABASE DSN1DB04.EMPTABSP
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UNLOAD DATABASE DSN1DB04 EMPTABSP
AI Explanation
To answer this question, let's go through each option to understand why it is correct or incorrect:
Option A) UNLOAD TABLE DSN1DB04.EMPTABSP - This option is incorrect because the syntax "UNLOAD TABLE" is not valid. The correct syntax is "UNLOAD TABLESPACE" to specify unloading a tablespace.
Option B) UNLOAD TABLESPACE DSN1DB04.EMPTABSP - This option is correct because it uses the correct syntax "UNLOAD TABLESPACE" to specify unloading a tablespace.
Option C) UNLOAD DATABASE DSN1DB04.EMPTABSP - This option is incorrect because the syntax "UNLOAD DATABASE" is not valid for unloading a specific table or tablespace. It is used for unloading the entire database.
Option D) UNLOAD DATABASE DSN1DB04 EMPTABSP - This option is incorrect because it does not specify the tablespace properly. The correct syntax for specifying a tablespace is "DSN1DB04.EMPTABSP" instead of "DSN1DB04 EMPTABSP".
The correct answer is Option B) UNLOAD TABLESPACE DSN1DB04.EMPTABSP. This option is correct because it uses the correct syntax for unloading a specific tablespace.
) While doing loading, data is sorted and then loaded into table (True or False)
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True
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False
AI Explanation
To answer this question, you need to understand the process of loading data into a table.
Option A) True - This option is incorrect. When loading data into a table, it is not necessary to sort the data before loading it. The data can be loaded into the table in any order, and the sorting can be done later if needed.
Option B) False - This option is correct. While loading data into a table, there is no requirement to sort the data before loading it. The data can be loaded into the table in any order.
Therefore, the correct answer is B) False.
While doing loading , indexes are built automatically(True or False)
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True
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False
The correct answer is A) True.
When data is loaded into a database, indexes can be automatically built on the specified columns. Indexes help improve query performance by allowing the database engine to quickly locate the rows that satisfy the search criteria. By automatically building indexes during the loading process, the database system can optimize the performance of queries executed on the loaded data.
Therefore, the statement that indexes are built automatically during loading is true.
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a table is unloaded
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a table is loaded
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an index is created
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a table is reorganized
To answer this question, let's go through each option to understand why it is correct or incorrect:
Option A) A table is unloaded - This option is correct. When a table is unloaded, there is no need to use RUNSTATS. Unloading a table means that the data is being removed from the table, and therefore, there is no data to collect statistics on.
Option B) A table is loaded - This option is incorrect. When a table is loaded, it is recommended to use RUNSTATS to collect statistics on the newly loaded data. This helps the database optimizer make better decisions when generating query plans.
Option C) An index is created - This option is incorrect. When an index is created, it is recommended to use RUNSTATS to collect statistics on the indexed columns. This helps the database optimizer make better decisions when using the index in query plans.
Option D) A table is reorganized - This option is incorrect. When a table is reorganized, it is recommended to use RUNSTATS to collect statistics on the reorganized table. This helps the database optimizer make better decisions when generating query plans for the reorganized table.
The correct answer is A) a table is unloaded. This option is correct because there is no need to use RUNSTATS when a table is unloaded, as there is no data to collect statistics on.
Therefore, the correct answer is option A.
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LOAD
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CHECK
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REORG
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RUNSTATS
Which utility should be used for maintaining consistency for list of tablespaces
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QUIESCE
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CHECK
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REORG
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RUNSTATS
AI Explanation
To maintain consistency for a list of tablespaces, the utility that should be used is QUIESCE.
Option A) QUIESCE - This option is correct because the QUIESCE utility is used to temporarily disable updates to a tablespace. It ensures that no changes are made to the data during maintenance operations, thus maintaining consistency.
Option B) CHECK - This option is incorrect because the CHECK utility is used to perform integrity checks on table data, but it does not specifically maintain consistency for tablespaces.
Option C) REORG - This option is incorrect because the REORG utility is used to reorganize table data and indexes, which can improve performance and reclaim space. While it can contribute to maintaining consistency indirectly, it is not the primary utility for this purpose.
Option D) RUNSTATS - This option is incorrect because the RUNSTATS utility is used to collect statistics about the data in a table or index, which helps the database optimizer make informed decisions about query execution. It does not directly maintain consistency for tablespaces.
The correct answer is A) QUIESCE. This option is correct because the QUIESCE utility is specifically designed to maintain consistency for a list of tablespaces by temporarily disabling updates.
Which utility should be used to restore DB2 tablespaces and indexes to a specific instance
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QUIESCE
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RECOVER
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REORG
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RUNSTATS
AI Explanation
To answer this question, you need to understand the purpose of each utility in DB2.
Option A) QUIESCE - This option is incorrect because the QUIESCE utility is used to temporarily halt the activity on a database or tablespace, allowing for maintenance operations to be performed. It does not restore tablespaces and indexes to a specific instance.
Option B) RECOVER - This option is correct. The RECOVER utility is used to restore and recover tablespaces and indexes in DB2. It allows you to restore data from a backup to a specific instance, ensuring data consistency and integrity.
Option C) REORG - This option is incorrect. The REORG utility is used to reorganize DB2 objects, such as tables and indexes, to improve performance and reclaim space. It does not restore tablespaces and indexes to a specific instance.
Option D) RUNSTATS - This option is incorrect. The RUNSTATS utility is used to collect statistics about DB2 objects, such as tables and indexes, to help the query optimizer make efficient execution plans. It does not restore tablespaces and indexes to a specific instance.
The correct answer is B) RECOVER. This option is correct because the RECOVER utility is specifically designed to restore and recover tablespaces and indexes in DB2.
Which utility should be used to obtain the access paths details?
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QUIESCE
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EXPLAIN
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REORG
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RUNSTATS
To answer this question, the user needs to have a basic understanding of database management systems and utilities used to manage databases.
QUIESCE is a utility used to temporarily halt the activity on the database, allowing for maintenance operations to take place. It is not used to obtain access path details.
EXPLAIN is a utility used to display the access path details for a particular SQL statement. This option is correct.
REORG is a utility used to reorganize the physical storage of a database table, and is not used to obtain access path details.
RUNSTATS is a utility used to collect statistical information about the data contained in a database table, and is not used to obtain access path details.
Therefore, the correct answer is:
The Answer is: B. EXPLAIN
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Triggering Table
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Triggering Event
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Triggered Action
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All the above
Triggers can not be used for
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Validate input data
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Automatically generate values for newly inserted rows
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support alerts
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To Implement Referential Integrity
AI Explanation
To answer this question, let's go through each option to understand why it is correct or incorrect:
Option A) Validate input data - This option is incorrect. Triggers can be used to validate input data. Triggers can be set to execute before or after an insert, update, or delete operation and can be used to enforce data validation rules.
Option B) Automatically generate values for newly inserted rows - This option is incorrect. Triggers can be used to automatically generate values for newly inserted rows. For example, a trigger can be set to insert a default value into a specific column when a new row is inserted.
Option C) Support alerts - This option is incorrect. Triggers can be used to support alerts. For example, a trigger can be set to send an alert or notification when a specific condition is met.
Option D) To implement Referential Integrity - This option is correct. Triggers cannot be used to implement referential integrity. Referential integrity is typically enforced through foreign key constraints and not through triggers.
The correct answer is D) To implement Referential Integrity. This option is correct because triggers are not used to implement referential integrity. Referential integrity is enforced through foreign key constraints.
Choose the correct options on acquiring locks
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If transaction A holds X lock on row R, If transaction B requests for S lock, then B would go into wait state until A releases the lock
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If transaction A holds S lock on row R, If transaction B requests for S lock, then B would be granted the lock
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If transaction A holds X lock on row R, If transaction B requests for X lock,then B would be granted the lock.
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If transaction A holds S lock on row R, If transaction B requests for X lock, then B would be granted the lock
AI Explanation
To answer this question, you need to understand the concept of locks in the context of transaction management. Let's go through each option to understand why it is correct or incorrect:
Option A) If transaction A holds X lock on row R, If transaction B requests for S lock, then B would go into a wait state until A releases the lock. This option is correct because in most concurrency control protocols, if a transaction holds an exclusive (X) lock on a resource (row R in this case), other transactions requesting shared (S) locks will be put into a wait state until the exclusive lock is released. This ensures that only one transaction at a time can have exclusive access to a resource.
Option B) If transaction A holds S lock on row R, If transaction B requests for S lock, then B would be granted the lock. This option is correct because shared (S) locks are compatible with other shared locks. If a transaction holds a shared lock on a resource, other transactions requesting shared locks on the same resource can be granted the lock. This allows multiple transactions to access the resource simultaneously.
Option C) If transaction A holds X lock on row R, If transaction B requests for X lock, then B would be granted the lock. This option is incorrect because exclusive (X) locks are not compatible with other exclusive locks. If a transaction holds an exclusive lock on a resource, other transactions requesting exclusive locks on the same resource will have to wait until the lock is released.
Option D) If transaction A holds S lock on row R, If transaction B requests for X lock, then B would be granted the lock. This option is incorrect because exclusive (X) locks are not compatible with shared (S) locks. If a transaction holds a shared lock on a resource, other transactions requesting exclusive locks on the same resource will have to wait until the shared lock is released.
The correct answers are A and B. These options correctly describe the behavior of locks in a transactional system.
Choose the correct options on LOCKSIZE
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Database
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Tablespace
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Table
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View
AI Explanation
To answer this question, you need to understand the concept of LOCKSIZE in the context of databases. LOCKSIZE determines the level at which locks are acquired and released during data modification operations.
Let's go through each option to understand why it is correct or incorrect:
Option A) Database - This option is incorrect because LOCKSIZE is not applicable at the database level. LOCKSIZE is set at a more granular level, such as tablespace, table, or view.
Option B) Tablespace - This option is correct because LOCKSIZE can be set at the tablespace level. By specifying the LOCKSIZE at the tablespace level, you can control how locks are acquired and released for tables within that tablespace.
Option C) Table - This option is correct because LOCKSIZE can also be set at the table level. By specifying the LOCKSIZE at the table level, you can control how locks are acquired and released for that particular table.
Option D) View - This option is incorrect because LOCKSIZE is not applicable at the view level. LOCKSIZE is typically associated with physical data structures like tablespace or table.
The correct answer is B and C. These options are correct because LOCKSIZE can be set at the tablespace and table levels to control how locks are acquired and released during data modification operations.
Referential constraint is
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Designates the values that columns of a table can contain
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The limiting of a set of foreign key values to a set of primary key values
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The limiting of a set of Primary key values to a set of foreign key values
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None of the above
When acquiring Tablespace lock more data is restricted than page level Lock (True or False)
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True
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False
A tablespace lock is the most restrictive type of lock in DB2. It prevents any other process from accessing any data in the tablespace. A page lock only prevents other processes from accessing the specific page that is locked.
Therefore, the statement "When acquiring Tablespace lock more data is restricted than page level Lock" is True.
A tablespace lock restricts access to all of the data in a tablespace, while a page lock only restricts access to a single page. This means that a tablespace lock is more restrictive than a page lock.
For example, if a tablespace contains 100 pages and a process acquires a tablespace lock on the tablespace, then no other process can access any of the data in the tablespace, even if the data is not on the page that is locked. However, if a process acquires a page lock on a single page in the tablespace, then other processes can still access the data on the other 99 pages in the tablespace.
In general, tablespace locks should only be used when it is absolutely necessary to prevent other processes from accessing any data in the tablespace. Page locks should be used whenever possible, as they provide a more granular level of locking and allow other processes to access more data.
Triggers can be defined on a system catalog table (True or False)
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True
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False
A system catalog is a group of tables and views that incorporate important information about a database. It includes tables that contain information about schemas, tables, columns, users, and so forth. A database management system (DBMS) typically manages these system catalog tables, and they are used to maintain consistent and reliable database operations.
While it's technically possible to create triggers on regular tables in a database, system catalog tables are typically not allowed to have triggers. The system catalog tables are managed by the DBMS itself, and any modifications to these tables are tightly controlled to avoid inconsistency or corruption of the system catalog. Therefore, DBMSs usually restrict users from creating triggers on system catalog tables.
Let's go through each option to understand why it is correct or incorrect:
Option A) True - This option is incorrect because system catalog tables are managed by the DBMS, and it typically prevents users from creating triggers on these tables.
Option B) False - This option is correct because, as mentioned above, creating triggers on system catalog tables is usually not allowed.
The correct answer is B) False. This option is correct because creating triggers on system catalog tables is typically not permitted by the DBMS to prevent potential data inconsistencies or system corruption.
MERGECOPY utility combines multiple incremental image copies into a full Image copy. ( True or False)
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True
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False
AI Explanation
To answer this question, we need to understand what the MERGECOPY utility does.
The MERGECOPY utility is used to combine multiple incremental image copies into a full image copy. Therefore, the statement "MERGECOPY utility combines multiple incremental image copies into a full image copy" is true.
Option A) True - This option is correct because the MERGECOPY utility does indeed combine multiple incremental image copies into a full image copy.
Option B) False - This option is incorrect because the statement is true.
The correct answer is A) True.