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.NET/Java PDF, Tiff, Barcode SDK LibraryIn Oracle Database 10g, active sessions are sampled every second, and the session information is stored in a circular buffer in SGA. A session that s either waiting for a non-idle event or that was on the CPU is considered an active session. Even though the ADDM provides you with detailed instance information by periodically analyzing the AWR data, you are at a loss if you want to know what s happened in the database in a recent time period (such as in the past five minutes). Active Session History (ASH) and its related historical views provide you with insight into current activity in the database. 18 discusses ASH in detail. barcode generator excel free download, creating barcodes in excel 2003, barcode font microsoft excel 2007, how to use barcode font in excel 2010, barcode generator excel 2003 free, barcode excel 2010 download, free barcode font for excel 2003, how to create barcodes in excel 2016, how to create barcode in excel 2007, barcode generator excel free,Oracle now sends out proactive server-generated alerts to warn you about problems like a tablespace running out of space. You can configure server-generated alerts by setting warning and critical thresholds on database metrics. The Oracle server automatically alerts you, for example, when the physical database reads per second cross a preset threshold value, or when a tablespace is low on free space. Server-generated alerts are discussed in 18. Oracle automatically performs certain maintenance tasks, such as collecting optimizer statistics, by using the new Scheduler feature. Oracle keeps track of which database objects don t have statistics or have stale statistics, and automatically refreshes statistics for these objects. In previous versions of Oracle, the DBA was responsible for collecting up-to-date statistics on all objects in the database. Now the database itself manages the collection of these statistics. Automated tasks are discussed in detail in 18. Our implementation uses the second (uncommented) line; it gets its data from the shadow file. You probably think the script could simply check for the existence of the shadow file; in case it isn t there, it should default to the passwd file. This would work in most but not all situations. I have worked on some machines that have both files but use only the /etc/passwd. I have also seen systems that will use the /etc/passwd file unless an /etc/ shadow exists. In that case the shadow file will be used. This script will, of course, need to be customized to fit your environment. You also need to check for a special case: if the encrypted password consists of a single asterisk (*) character, you have to escape it with a backslash (\). If the asterisk isn t escaped, it will be evaluated later as a wild card denoting all filenames residing in the current working directory (the traditional meaning of *). In a shell environment, another method to get around this problem would be to set noglob, which turns off that type of evaluation. The manageability infrastructure, as well as all the automatic management features, are installed when you install the Oracle Database 10g software. Oracle Database 10g comes with several management advisors, which help tune your SQL queries, size your memory and undo configuration parameters, and figure out the right indexes and materialized views for your database. The advisors use a uniform interface the Advisor Central in the OEM, or the DBMS_ADVISOR package, when you invoke them manually. All the advisors use the Automatic Workload Repository as the source of their data and as a repository for their reports. 18 introduces the advisory framework in detail. Here s a brief description of the main management advisors, which you ll see in detail in later chapters. The SQL Tuning Advisor provides recommendations for running SQL statements faster, by replacing manual tuning with tuning suggested by the Automatic Tuning Optimizer, which is the Cost Optimizer in a tuning mode. The advisor calls the Automatic Tuning Optimizer (ATO) to perform optimizer statistics analysis, SQL profiling, access-path analysis, and SQL structure analysis. The SQL Tuning Advisor is discussed in detail in 21. Even though it is possible to catch managed exceptions in native code, it is seldom useful. Since native code cannot use any managed types, your exception handler cannot get information about the managed exception that it catches. Managed exceptions are caught as Win32 SEH exceptions with the exception code 0xE0434F4D. The following code catches a System::Exception in native code: // ExceptionHandling3.cpp // compile with "cl /clr ExceptionHandling3.cpp" #include <excpt.h> #include <windows.h> #include <iostream> using namespace std; void f() { throw gcnew System::Exception("Managed exception thrown to native code"); }
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