SQL server optimization interview questions and answers

<<Previous  Next>>

What are the steps you will take, if you are tasked with securing an SQL Server?
What is a deadlock and what is a live lock? How will you go about resolving deadlocks?
Explain 'Hostprotectionattribute' in SQL server 2005.

SQL Server Optimization - August 29, 2008 at 18:00 PM by Amit Satpute What are the steps you will take, if you are tasked with securing an SQL Server? Perform the following SQL checks after installing the Server: Check if Administrators group belongs to sysadmin role Check if CmdExec role is restricted to sysadmin only Check if SQL Server is running on a Domain Controller Check if sa account password is exposed Check SQL installation folders access permissions Check if Guest account has database access Check if the Everyone group has access to SQL registry keys Check if SQL service accounts are members of the local Administrators group Check if SQL accounts have blank or simple passwords Check for missing SQL hotfixes Check the SQL Server authentication mode type Check the number of sysadmin role members Then, you should require Windows Authentication Mode for connections to SQL Server, whenever possible. You should isolate your server and back it up regularly. You should assign a strong sa password. You should limit privilege level of SQL Server Services. Configure your firewall to filter out packets addressed to TCP port 1433 and UDP port 1434. ports associated with named instances should also be blocked at the firewall. You should Use a secure file system. Old setup files should be Deleted or secured. You should log failed connection attempts to SQL Server and review the log regularly.Enable auditing of failed connections with Enterprise Manager in SQL Server. What is a deadlock and what is a live lock? How will you go about resolving deadlocks? A deadlock can occur when two or more processes that strive to acquire resources are not able to acquire them due to some of the following reasons: Two processes may be interdependent upon each other, If there are more than 2 processes, then if a graph is plotted, then there could be a cycle, A server maintains a graph. The processes acquiring the resources would intimate the server about their requirement. If the server detects an occurance of a deadlock, the user process is be terminated. In a livelock, a request for an exclusive lock is denied repeatedly due to a series of overlapping shared locks that keep interfering. An SQL Server detects this situation after four denials and then refuses further shared locks. When a write transaction is forced to wait indefinitely due to read transactions that monopolize a table or a page then a live lock occurs. Explain 'Hostprotectionattribute' in SQL server 2005. It allows the use of declarative security actions to determine host protection requirements. This class cannot be inherited <<Previous  Next>> Also read What are the rules to use the ROWGUIDCOL property to define a globally unique identifier column? Answer - A table can have only one ROWGUIDCOL column...... What are the guidelines to use bulk copy utility of SQL Server? Answer - While importing data, the destination table must already exist...... What are the advantages of using Stored Procedures? Answer - Stored procedures provide performance benefits through local storage, precompiling the code, and caching...... What are the differences among batches, stored procedures, and triggers? Answer - A batch is a group of one or more SQL statements. SQL Server compiles the statements...... What are the instances when triggers are appropriate? What are the restrictions applicable while creating views? Answer - Views can be created referencing tables and views only in the current database....... Describe when checkpoints are created in a transaction log. Answer - It is created when CHECKPOINT statement is executed....... What are the lock types? Answer - Shared Lock allows simultaneous access of record by multiple Select statements. Shared Lock blocks record from updating and will remain in queue waiting while record is accessed for reading...... Define Identity and uniqueidentifier property of Column. Answer - Column with identity property contains unique system generated value in the table. Column with identity property is similar to AutoNumber field in MS Access.... What are Indexes? Define B-tress. What is FillFactor? What are Index Statistics? Define Fragmentation. Write your comment - Share Knowledge and Experience