SQL Server TSQLquiz - 8 - Quiz & Trivia

1. What is a table called, if it does not have either aClustered or a nonclustered index?

Heap

Temporary table

Partitioned table

Unclustered table

A table without either a clustered or a nonclustered index is called a heap. In a heap, the data is stored in an unordered manner, without any specific organization or sorting. This can result in slower data retrieval and manipulation compared to tables with indexes. However, heaps can be useful in certain scenarios, such as when the table is frequently modified or when the data is accessed in a sequential manner.

Explanation

A table without either a clustered or a nonclustered index is called a heap. In a heap, the data is stored in an unordered manner, without any specific organization or sorting. This can result in slower data retrieval and manipulation compared to tables with indexes. However, heaps can be useful in certain scenarios, such as when the table is frequently modified or when the data is accessed in a sequential manner.

2. What is the difference between the following 2 queries: -- 1 SELECT ROW_NUMBER() OVER (ORDER BY NEWID()) FROM sys.all_columns -- 2 SELECT ROW_NUMBER() OVER (ORDER BY (SELECT NEWID())) FROM sys.all_columns

The first query returns an error and the second returns a Tally table.

No difference

not-available-via-ai

Explanation

not-available-via-ai

3. NTILE returns what?

The rows in an ordered partition into a specified number of groups.

The rank of rows within the partition of a result set, without any gaps in the ranking

NTILE returns the rows in an ordered partition into a specified number of groups. This means that it divides the result set into equal-sized groups based on the specified number. Each row is assigned a sequential number representing the group it belongs to. This function is useful for analyzing data distribution and creating percentiles or quartiles.

Explanation

NTILE returns the rows in an ordered partition into a specified number of groups. This means that it divides the result set into equal-sized groups based on the specified number. Each row is assigned a sequential number representing the group it belongs to. This function is useful for analyzing data distribution and creating percentiles or quartiles.

4. True or False: sparse Columns can have the Filestream attribute defined on them?

True

False

Sparse columns cannot have the Filestream attribute defined on them. The Filestream attribute is used to store large binary data outside the database, while sparse columns are used to optimize storage for columns that contain mostly NULL values. These two features serve different purposes and cannot be used together.

Explanation

Sparse columns cannot have the Filestream attribute defined on them. The Filestream attribute is used to store large binary data outside the database, while sparse columns are used to optimize storage for columns that contain mostly NULL values. These two features serve different purposes and cannot be used together.

5. What will be the values returned by the COUNT(*) statements ? (select the answer that show the 3 values in correct order) CREATE TABLE #TempTable (RowID INT) CREATE TABLE UserTable (RowID INT) BEGIN TRAN INSERT UserTable (RowID) VALUES (1) ROLLBACK INSERT UserTable (RowID) VALUES (2) BEGIN TRAN INSERT #TempTable (RowID) VALUES (1) ROLLBACK INSERT #TempTable (RowID) VALUES (2) DECLARE @TableVariable TABLE (RowID INT) BEGIN TRAN INSERT @TableVariable (RowID) VALUES (1) ROLLBACK INSERT @TableVariable (RowID) VALUES (2) SELECT COUNT(*) FROM UserTable SELECT COUNT(*) FROM #TempTable SELECT COUNT(*) FROM @TableVariable DROP TABLE #TempTable DROP TABLE UserTable

1,1,1

1,1,2

1,2,2

2,2,2

The first INSERT statement is rolled back, so no rows are actually inserted into the UserTable. The second INSERT statement inserts one row with a value of 2 into the UserTable. Therefore, the COUNT(*) statement for the UserTable will return a value of 1.

The first INSERT statement for the #TempTable is also rolled back, so no rows are inserted. The second INSERT statement inserts one row with a value of 2 into the #TempTable. Therefore, the COUNT(*) statement for the #TempTable will return a value of 1.

The first INSERT statement for the @TableVariable is rolled back, so no rows are inserted. The second INSERT statement inserts one row with a value of 2 into the @TableVariable. Therefore, the COUNT(*) statement for the @TableVariable will return a value of 1.

Explanation

The first INSERT statement is rolled back, so no rows are actually inserted into the UserTable. The second INSERT statement inserts one row with a value of 2 into the UserTable. Therefore, the COUNT(*) statement for the UserTable will return a value of 1.

The first INSERT statement for the #TempTable is also rolled back, so no rows are inserted. The second INSERT statement inserts one row with a value of 2 into the #TempTable. Therefore, the COUNT(*) statement for the #TempTable will return a value of 1.

The first INSERT statement for the @TableVariable is rolled back, so no rows are inserted. The second INSERT statement inserts one row with a value of 2 into the @TableVariable. Therefore, the COUNT(*) statement for the @TableVariable will return a value of 1.

6. What will be the output of these SELECT queries? DECLARE @var money = 123457756 Declare @dec decimal =12345 Declare @dec1 Decimal(10,2) = 12345 --Select 1 SELECT LEN(@var) --Select 2 SELECT LEN(@dec) --Select 3 SELECT LEN(@dec1)

12,5,8

9,5,5

12,8,8

9,8,5

The first SELECT query returns the length of the string representation of the @var variable, which is 12.

The second SELECT query returns the length of the string representation of the @dec variable, which is 5.

The third SELECT query returns the length of the string representation of the @dec1 variable, which is 8.

Explanation

The first SELECT query returns the length of the string representation of the @var variable, which is 12.

The second SELECT query returns the length of the string representation of the @dec variable, which is 5.

The third SELECT query returns the length of the string representation of the @dec1 variable, which is 8.

7. Declare @value int set @value = 5555555 PRINT CONVERT(varchar(6), @value) What will be the output?

Arithmetic overflow error converting expression to data type varchar.

*

555555

5555555

The code snippet sets the value of the variable @value to 5555555 and then tries to convert it to a varchar(6) data type. However, since the value is too large to fit within 6 characters, it causes an arithmetic overflow error. Therefore, the correct answer is "*".

Explanation

The code snippet sets the value of the variable @value to 5555555 and then tries to convert it to a varchar(6) data type. However, since the value is too large to fit within 6 characters, it causes an arithmetic overflow error. Therefore, the correct answer is "*".

8. You wish to enable xp_cmdshell. You run the following code: EXECUTE sys.sp_configure @configname = 'show advanced options' ,@configvalue = 1 GO RECONFIGURE GO EXECUTE sys.sp_configure @configname = 'dsh' ,@configvalue = 1 GO RECONFIGURE GO

The first call to sp_configure succeeds

The second call to sp_configure fails

The second call to sp_configure succeeds

The first call to sp_configure succeeds because it sets the value of the 'show advanced options' configuration option to 1. This allows the system to display advanced configuration options. The second call to sp_configure also succeeds because it sets the value of the 'dsh' configuration option to 1, enabling the xp_cmdshell feature.

Explanation

The first call to sp_configure succeeds because it sets the value of the 'show advanced options' configuration option to 1. This allows the system to display advanced configuration options. The second call to sp_configure also succeeds because it sets the value of the 'dsh' configuration option to 1, enabling the xp_cmdshell feature.

Submit

9. I have a table, Sales, with the Notes field having the Filestream attribute. I run this query: select salesmen, notes into #salestemp from Sales What is the data type of the Notes field in the temporary table?

Varchar(max)

Varchar(max) with the filestream attribute

Varbinary(max)

Varbinary(max) with filestream attribute

The data type of the Notes field in the temporary table is varbinary(max) because the original Notes field in the Sales table has the Filestream attribute, which indicates that the data is stored as binary data. Therefore, when the data is copied into the temporary table, it retains the varbinary(max) data type.

Explanation

The data type of the Notes field in the temporary table is varbinary(max) because the original Notes field in the Sales table has the Filestream attribute, which indicates that the data is stored as binary data. Therefore, when the data is copied into the temporary table, it retains the varbinary(max) data type.

10. What technique is used by the SQL Server to maintain Durability of Transactions?

BEGIN...END Block

Write Ahead Logging

Locking

AutoCommit Transactions

Write Ahead Logging is a technique used by SQL Server to maintain Durability of Transactions. This technique ensures that all changes made by a transaction are first written to a log file before being written to the database. This log file serves as a record of all the changes made, allowing for recovery in case of system failure or crash. By using Write Ahead Logging, SQL Server ensures that committed transactions are durable and can be recovered even in the event of a failure.

Explanation

Write Ahead Logging is a technique used by SQL Server to maintain Durability of Transactions. This technique ensures that all changes made by a transaction are first written to a log file before being written to the database. This log file serves as a record of all the changes made, allowing for recovery in case of system failure or crash. By using Write Ahead Logging, SQL Server ensures that committed transactions are durable and can be recovered even in the event of a failure.