.NET/Java PDF, Tiff, Barcode SDK Library

METRIC_NAME VALUE -----------------------------------------------Database Wait Time Ratio 72 Database CPU Time Ratio 28 SQL> Once you realize that the total instance wait time ratio is much higher than the CPU time ratio, you can explore things further. Wait classes provide a quick way to figure out why the database instance is performing poorly. In the example shown in Listing 22-14, you can easily see that user I/O waits are responsible for most of the wait time. You can establish this fact by looking at the PCT_TIME column, which gives you the percentage of time attributable to each wait class. Total waits are often misleading, as you can see by looking at the NETWORK wait class. In percentage terms, network waits are only 1 percent, although total network waits constitute more than 51 percent of total waits in this instance. Listing 22-14. Determining Total Waits and Percentage Waits by Wait Class SQL> 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16* SELECT WAIT_CLASS, TOTAL_WAITS, round(100 * (TOT_WAITS / SUM_WAITS),2) PCT_TOTWAITS, ROUND((TIME_WAITED / 100),2) TOT_TIME_WAITED, round(100 * (TOT_TIME_WAITED / SUM_TIME),2) PCT_TIME FROM (select WAIT_CLASS, TOT_WAITS, TOT_TIME_WAITED FROM V$SYSTEM_WAIT_CLASS WHERE WAIT_CLASS != 'Idle'), (select sum(TOT_WAITS) SUM_WAITS, sum(TOT_TIME_WAITED) SUM_TIME from V$SYSTEM_WAIT_CLASS where WAIT_CLASS != 'Idle') ORDER BY PCT_TIME DESC; PCT_TOT_WAITS ------------45.07 2.67 .53 51.15 .01 .11 .09 .36 0 0 TOT_TIME_WAITED PCT_TIME --------------- -------46305770.5 84.42 5375324.17 9.8 1626254.9 2.96 547128.66 1 449945.5 .82 351043.3 .64 116029.85 .21 78783.64 .14 7.6 0 .15 0

barcode add in excel 2003, barcode erstellen excel kostenlos, active barcode in excel 2003, excel 2013 barcode font download, random barcode generator excel, active barcode excel 2010 download, microsoft excel barcode font free, how to make barcodes in excel mac 2011, barcode addin excel 2013, excel 2010 barcode control,

C++/CLI is not only the tool of choice for extending existing C++ applications with .NET features, but it is also the primary tool for creating mixed-code libraries. These libraries can be simple one-to-one wrappers for native APIs; however, in many scenarios it is useful to do more than that. Making existing C++ libraries available to .NET developers so that they can make the best use of them requires giving an existing API a .NET-like face. In .NET, there is a new type system with new features, and there are also new philosophies related to class libraries, error reporting, data communication, and security that all have to be considered to make a wrapper a successful .NET library. Several chapters of this book are dedicated to different tasks of wrapping native libraries. s 5 and 6 explain how to define the various kinds of managed types and type members, and show the .NET way to map different kinds of relationships to a system of managed types. In 10, important design and implementation aspects of wrapper libraries are discussed. Finally, 11 explains how to use the reliability features provided by .NET to ensure that the wrapped resources are cleaned up even in critical scenarios like stack overflows. High reliability is of special importance if a wrapper library is used in long-running servers.

WAIT_CLASS TOTAL_WAITS ------------- ----------User I/O 6649535191 Other 394490128 Concurrency 78768788 Network 7546925506 Application 2012092 Commit 15526036 Configuration 12898465 System I/O 53005529 Administrative 25 Scheduler 1925 10 rows selected. SQL>

The key dynamic performance tables for finding wait information are the V$SYSTEM_EVENT, V$SESSION_EVENT, V$SESSION_WAIT, and the V$SESSION views. The first two views show the waiting time for different events.

1. Note the leading carat (^) in the subnet that specifies lines beginning with that subnet. Without this character, IP addresses that simply contain 172.16.5 also would be replaced.

The V$SYSTEM_EVENT view shows the total time waited for all the events for the entire system since the instance started up The view doesn t focus on the individual sessions experiencing waits, and therefore it gives you a high-level view of waits in the system You can use this view to find out what the top instance-wide wait events are You can calculate the top n waits in the system by dividing the event s wait time by the total wait time for all events The three key columns of the V$SYSTEM_EVENT view are total_waits, which gives the total number of waits; time_waited, which is the total wait time per session since the instance started; and average_wait, which is the average wait time by all sessions per event The V$SESSION_EVENT view is similar to the V$SYSTEM_EVENT view, and it shows the total time waited per session.

All the wait events for an individual session are recorded in this view for the duration of that session By querying this view, you can find out the specific bottlenecks encountered by each session The third dynamic view is the V$SESSION_WAIT view, which shows the current waits or justcompleted waits for sessions The information on waits in this view changes continuously based on the types of waits that are occurring in the system The real-time information in this view provides you with tremendous insight into what s holding up things in the database right now The V$SESSION_WAIT view provides detailed information on the wait event, including details such as file number, latch numbers, and block number This detailed level of information provided by the V$SESSION_WAIT view enables you to probe into the exact bottleneck that s slowing down the database.