Oracle8 Database Management Part 1
Terms
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- The estimation of the hardware requirements necessary to process a workload within specified parameters is referred to as?
- computer sizing
- What are the Parameters necessary to process a workload referred to?
- Service Level Agreements
- What type of requirements does computer sizing estimate?
- Hardware
- What must be defined before you can make computer sizing decisions?
- Parameters
- What Server hardware addition would be needed to decrease Oracle Transaction time?
- Buying more Disks
- What's most frequently needed to reduce Oracle 8 processor utilization?
- Memory
- The performance study of hardware and software resource consumption on an existing system to prepare for the growth of that system's workload is referred to as?
- Capacity Planning
- What is ther term used for projecting Normal growth of CPU utilization; Disk Usage; Memory usage?
- Capacity planning studies
- What are capacity-planning studies established to maintain?
- Service level agreements
- Why would the activities of specific users be profiled during a capacity-planning study?
- To predict resource consumption
- A database server performs only database functions. In terms of workload, it performs only?
- Transactions
- What are the 2 main types of Transactions?
- online transaction processing (OLTP) and decision support.
- This transaction type is constantly updating the database based on the most current information available so the next user can rely on that information being the most current.
- OLTP
- What's the first category of info gathered in the interview process?
- concurrent users
- What's the second category of info gathered in the interview process?
- The number of transactions expected to be processed
- what's the 3rd type of info gathered in the interview process?
- what time range these transactions are expected to be processed
- what's the 4th type of info gathered in the interview process?
- Whether this time range is your peak-utilization period
- generally used when you cannot define the peak-utilization period.
- steady-state processing
- refers to a portion of system processing power left in reserve to accommodate heavier workload periods
- reserve capacity
- This theory states that utilization directly affects the queues and these queues are directly related to response time .
- knee of the curve
- At what point of utilization do queues begin to grow exponentially in length?
- 75%
- What principle should you consider when selecting the number of CPU's your system will require?
- Knee of the Curve
- What is the knee of the curve % for disks?
- 85%
- What can be minimized by adhering to the knee of the curve principle as applied to disks?
- Response times
- If a user process needs a data record or a system needs a code page and it is found in memory, this is called a
- Logical I/O
- This occurs when the system or a user function determines that certain information that it must process is not in memory?
- page fault
- When the system or user function retrieves the data from physical disk, replacing data currently in memory it is referred to as?
- physical I/O
- Retrieval time for the data found in memory is rated in?
- microseconds
- retrieval time for the data found on disk is rated in?
- milliseconds
- If a user process needs a data record or a system needs a code page and it is NOT found in memory, what normal system function occurs?
- page fault
- Where does the system retrieve information from during a logical I/O?
- memory
- When the next program code address is not in memory. The system must go to the disk drive to retrieve it. This is called?
- code page fault
- This two-step page fault occurs when a user process requests a data record that is not in memory, and the data page currently in memory has been modified
- page fault swap
- When the data page current in memory has been modified, it's called?
- dirty data page
- Which type of page fault causes the most damage to response time?
- Page fault swaps
- What principle is used in the calculation of minimum memory?
- page fault principle
- This type of system is generally used to provide information to management so decisions can be made about issues such as business growth, levels of stock on hand
- Decision Support System
- What is most important in DSS Systems
- minimize process request time
- In the OLTP system, the rate of the throughput of transactions is commonly measured in
- tps or tpm
- With DSS, throughput is usually measured in?
- qph
- This system can be 1 TB in size and Measures throughput in QPH
- DSS
- This system measures throughput in TPM and must have 75% processor utilization?
- oltp
- 3 factors for determining cpu and memory requirements are?
- number of users, transaction type and OS
- To size a database server you need to know which 2 things?
- number of concurrent users and number of transaction i/o user requests will generate
- When calculating the proper amount of memory for your system, the person performing the sizing must take into account?
- desirable cache-hit rate and page faulting
- What information do you need to size a database server?
- Number of concurrent user connections and number of transaction I/Os
- Oracle 8 uses how much memory for each user connected?
- 500kb
- What is the memory usage for Oracle on Windows NT?
- 18mb
- Oracle 8 database executable used how much memory?
- 5.5mb
- What information needed to size a database server is indicative only to Oracle databases?
- size of SGA
- What are SGA's 3 main facets that should be considered for determining Oracle 8 memory needs?
- shared pool size, log buffer size and database buffer size
- SGA shared pool area consists of these 2 sub areas?
- library cache and dictionary cache
- contains procedures that are internally formatted (parsed) and are commonly used by the system
- library cache
- This cache contains the most frequent requests pertaining to the database.
- dictionary cache
- Shared pool memory size for a)<44 users, b)44-95 users, c)95+ users
- a)3.5mb, b)6mb, c)9mb
- What does the dictionary cache contain?
- database requests
- the second part of the SGA that determines the size of memory and holds information about the write activity taking place.
- log buffer area
- recommended log buffer size for a)<44, b)44-95, c)95+
- a)8,192bytes, b)32,768bytes, c)163,840bytes
- When the log buffer fills up, this process writes the contents of the buffer to the redo log files associated with the database.
- lgwr
- This SGA area is the cache area of your system. All the data that is processed by your system will pass through this area.
- database buffer
- What size does the calculation for log buffer size relate to?
- Concurrent user community
- Within what file does the parameter DB_BLOCK_BUFFERS exist?
- initorcl.ora
- refers to the quantity of database buffers that this system will have?
- DB_BLOCK_BUFFERS
- refers to the size that each block will be
- DB_BLOCK_SIZE
- Which two things increase when a cache area is too small?
- occurrence of physical i/o's and response time.
- What increases relative to how high the DB_BLOCK_BUFFER parameter is set?
- transaction completions
- The target cache-hit rate for your system should be as close to what percent?
- 90%
- What do you need to calculate once you know how to set DB_BLOCK_BUFFERS properly?
- DB_BUFFER_SIZE
- These two scripts may use to retrieve additional information needed to calculate the target cache-hit rate. script a) before performing test run and b) after test run.
- a)utlbstat.sql and b)utlestat.sql
- What script is used to calculate the target cache-hit rate?
- ulestat
- What does understanding the transaction anatomy help calculate?
- CPU utilization
- allow the system to split the access of the mirrored drives in two.
- split seaks
- how to determine i/o for RAID 1?
- I/O=READS_PER_TRANS+(WRITES_PER_TRANS*2)
- How to determine RAID 5 I/O total?
- RAID 5 Trans I/O=(READS_PER_TRANS+(WRITES_PER_TRANS*2 for reads))+(WRITES_PER_TRANS*2 for writes)
- What must be calculated before figuring anticipated CPU utilization?
- total reads
- What type of reads involve more intervention by the CPU?
- physical
- allows a large query to be broken into segments based and to hit the database simultaneously, thus expediting processing.
- Parallel Query
- Approximately how many seconds does it take to write a block from memory to disk?
- .001
- What percentage rate should the number of proposed CPUs keep TOTAL_CPU_UTILIZATION below?
- 75%
- What order should these be in to keep cpu utilization under 75% 1)Calculate Total Writes 2)Calculate Transaction Utilization 3)Calculate CPU Write Time
- 132
- What sizing option is available on a DSS system utilizing multiple CPU's?
- parallel query
- what is the disk usage percentage when sizing the disk subsystem?
- 85%
- What does OS_ORACLE_DISK*RAID_FACTOR determine
- Number of disk drives
- what raid level is recommended for OS and Oracle Database?
- Raid 1
- what RAID level is recommended for the database drives?
- RAID 5
- What kind of information is kept on log disk drives?
- Audit Trails
- What variable is extremely important when calculating the number of log disk drives?
- Number of writes-per-second