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SQL Chapters 5-8
Chapters 5-8
Question | Answer |
---|---|
What are the components of an RDBMS? | Maintains the relationships among data in a database. Ensures that data are stored correctly and the rules defining the relationships among data are not violated. Recovers data to a point of known consistency in the event of an infrastructure failure. |
What are the two types of files SQL uses to store database information? | One or more transaction files and one or more database files. |
What are the 3 types of files that Databases are comprised of? | primary data files, secondary data files and transaction logs |
What is the file extension for primary data files? | mdf |
What is the file extension for secondary data files? | ndf |
What is the file extension for transaction logs? | ldf |
Transaction logs should be placed on separate physical hard drives (spindles). T or F? | True |
What are the three recovery models? | Simple, Bulk-Logged, and Full |
If you do not specify a size for the transaction log, what size will it default to? | 25% of the size of the data file request. |
What is an ANSI-compliant term for a database? | catalog |
Which database is a new database copied from? | model |
What are the measures you can take to ensure the reliability and consistency of your database? | The different levels of Redundant Array of Independent Disks (RAID). |
What are the main configurations of RAID? | RAID 0, RAID 1, RAID 5, RAID 10. |
Which RAID is associated with disk mirroring? | RAID 1 |
Which RAID is associated with striping with parity? | RAID 5 |
What does striping with parity accomplish? | It writes data to the hard disk in stripe sets. Parity checksums are written across all disks in the stripe set. This gives excellent fault tolerance, as well as excellent speed with a reasonable amount of overhead. |
When should RAID 10 be used? | In mission-critical systems that require 24/7 uptime and the fastest possible access. RAID 10 implements striping and then mirrors the stripe sets. |
What is the drawback of RAID 10? | It is expensive and uses more than twice the disk space of RAID 1. |
What is an extent? | A block of eight pages totaling 64KB in size. |
What are the two types of extents? | Uniform and mixed |
What is disk mirroring? | Writes the information to disk twice, once to the primary drive, and once to the mirror drive. |
What is the advantage of disk mirroring? | It gives excellent fault tolerance. |
What is the disadvantage of disk mirroring? | It is slow because you must write to two different hard drives. |
Which RAID gives the best performance? | RAID 0 |
What is the disadvantage of RAID 0? | It does not offer fault tolerance. |
What technology allow you to combine multiple hard drives to increase availability and/or performance? | RAID |
At the most fundamental level, where does SQL Server store everything? | on a page |
What are the common denominators of a page? | They are always 8 KB in size and always have a header, leaving about 8,060 bytes of usable space on every page. |
What is necessary for recovering data if you use a full or bulk-logged recovery model? | make regular backups of your transaction logs. |
What is a two-dimensional object that consists of rows and columns? | table |
What statement would you use to create a table? | CREATE TABLE |
What are the two new data compression features for reducing the disk space requirements introduced in SQL Server 2008? | row compression and page compression |
Which version of Windows Server 2008 support data compression? | Enterprise, Developer, and Evaluation Editions |
How can you make a table smaller without losing data so that it can be more maneageable? | partition the table |
What process is used to divide the table into multiple sections that can be stored and accessed independently without the users' knowledge? | partitioning the table |
What happens when you partition tables and views across multiple servers? | a federation of servers |