crystal reports barcode font formula PERFOR MAN CE TUNING: TUNING THE INSTA NCE in Font

Encode Code 39 Extended in Font PERFOR MAN CE TUNING: TUNING THE INSTA NCE

CHAPTER 20 PERFOR MAN CE TUNING: TUNING THE INSTA NCE
Printing ANSI/AIM Code 39 In None
Using Barcode maker for Font Control to generate, create USS Code 39 image in Font applications.
www.OnBarcode.com
QR Code Generator In None
Using Barcode encoder for Font Control to generate, create QR Code 2d barcode image in Font applications.
www.OnBarcode.com
NAMESPACE -----------------BODY CLUSTER INDEX JAVA DATA JAVA RESOURCE JAVA SOURCE OBJECT PIPE SQL AREA TABLE/PROCEDURE TRIGGER 11 rows selected. SQL>
Make PDF-417 2d Barcode In None
Using Barcode generator for Font Control to generate, create PDF-417 2d barcode image in Font applications.
www.OnBarcode.com
Code-128 Creator In None
Using Barcode maker for Font Control to generate, create Code 128 Code Set C image in Font applications.
www.OnBarcode.com
PINS -----25 248 31 6 2 0 0 0 390039 3532 5
EAN 13 Generator In None
Using Barcode generation for Font Control to generate, create EAN / UCC - 13 image in Font applications.
www.OnBarcode.com
Barcode Encoder In None
Using Barcode drawer for Font Control to generate, create Barcode image in Font applications.
www.OnBarcode.com
PINHITS ---------12 239 0 4 1 0 0 0 389465 1992 3
Printing Data Matrix In None
Using Barcode encoder for Font Control to generate, create ECC200 image in Font applications.
www.OnBarcode.com
Encoding 2 Of 7 Code In None
Using Barcode drawer for Font Control to generate, create Monarch image in Font applications.
www.OnBarcode.com
RELOADS ------0 0 0 0 0 0 0 0 14 0 0
Code 39 Extended Printer In Visual C#
Using Barcode creator for VS .NET Control to generate, create Code 3/9 image in VS .NET applications.
www.OnBarcode.com
Make Code 39 Full ASCII In None
Using Barcode maker for Software Control to generate, create Code 39 image in Software applications.
www.OnBarcode.com
If the RELOADS column of the V$LIBRARYCACHE view shows large values, it means that many SQL statements are being reloaded into the library pool after they ve been aged out. You might want to increase your shared pool, but this still may not do the trick if the application is large, the number of executions is large, or the application doesn t use bind variables. If the SQL statements aren t exactly identical and/or if they use constants instead of bind variables, more hard parses will be performed, and hard parses are inherently expensive in terms of resource usage. You can force the executable SQL statements to remain in the library cache component of the shared pool by using the Oracle-provided DBMS_SHARED_POOL package. The package has the KEEP and UNKEEP procedures; using these you can retain and release objects in the shared pool. You can use the V$LIBRARY_CACHE_MEMORY view to determine the number of library cache memory objects currently in use in the shared pool and to determine the number of freeable library cache memory objects in the shared pool. The V$SHARED_POOL_ADVICE view provides you with information about the parse time savings you can expect for various sizes of the shared pool.
1D Encoder In Visual C#
Using Barcode generation for Visual Studio .NET Control to generate, create 1D image in VS .NET applications.
www.OnBarcode.com
Making 2D Barcode In Visual Studio .NET
Using Barcode creator for ASP.NET Control to generate, create 2D Barcode image in ASP.NET applications.
www.OnBarcode.com
Optimizing the Library Cache
Paint Code 39 Full ASCII In None
Using Barcode printer for Excel Control to generate, create Code 3/9 image in Excel applications.
www.OnBarcode.com
Make Linear In Visual Studio .NET
Using Barcode encoder for .NET framework Control to generate, create Linear image in Visual Studio .NET applications.
www.OnBarcode.com
You can configure some important initialization parameters so the library cache areas are used efficiently. You ll look at some of these initialization parameters in the following sections.
Printing GS1 DataBar Truncated In VS .NET
Using Barcode maker for VS .NET Control to generate, create DataBar image in .NET framework applications.
www.OnBarcode.com
Scan EAN 13 In None
Using Barcode scanner for Software Control to read, scan read, scan image in Software applications.
www.OnBarcode.com
Using the CURSOR_SHARING (Literal Replacement) Parameter
Barcode Printer In Objective-C
Using Barcode generation for iPhone Control to generate, create Barcode image in iPhone applications.
www.OnBarcode.com
Code 39 Full ASCII Maker In Objective-C
Using Barcode creator for iPhone Control to generate, create Code-39 image in iPhone applications.
www.OnBarcode.com
The key idea behind optimizing the use of the library cache is to reuse previously parsed or executed code. One of the easiest ways to do this is to use bind variables rather than literal statements in the SQL code. Bind variables are like placeholders: they allow binding of application data to the SQL statement. Using bind variables enables Oracle to reuse statements when the only things changing in the statements are the values of the input variables. Bind variables enable you to reuse the cached, parsed versions of queries and thus speed up your application. Here s an example of the use of bind variables. The following code sets up a bind variable as a number type: SQL> VARIABLE bindvar NUMBER; SQL> BEGIN 2 :bindvar :=7900; 3 END; 4 / PL/SQL procedure successfully completed. SQL>
PDF 417 Drawer In Visual C#
Using Barcode creator for .NET framework Control to generate, create PDF-417 2d barcode image in .NET applications.
www.OnBarcode.com
QR Code ISO/IEC18004 Printer In Visual C#
Using Barcode generation for Visual Studio .NET Control to generate, create Denso QR Bar Code image in .NET framework applications.
www.OnBarcode.com
CH A PT ER 2 0 PERF O RMAN CE TUNI NG: TUN ING TH E I NS TA NCE
You can now issue the following SQL statement that makes use of the bind variable you just created: SQL> SELECT ename FROM scott.emp WHERE empid = :bindvar; ENAME JAMES You can execute this statement multiple times with different values for the bind variable. The statement is parsed only once and executes many times. Unlike when you use a literal value for the emp_id column (7499, for example), Oracle reuses the execution plan it created the first time, instead of creating a separate execution plan for each such statement. This cuts hard parsing (and high latch activity) and the attendant CPU usage drastically, and dramatically reduces the time taken to retrieve data. For example, all the following statements can use the parsed version of the query that uses the bind variable: SELECT ename FROM scott.emp WHERE empid = 7499; SELECT ename FROM scott.emp WHERE empid = 7788; SELECT ename FROM scott.emp WHERE empid = 7902; Unfortunately, in too many applications, literal values rather than bind values are used. You can alleviate this problem to some extent by setting up the following initialization parameter: CURSOR_SHARING=FORCE Or you could use the following parameter: CURSOR_SHARING=SIMILAR By default, the CURSOR_SHARING initialization parameter is set to EXACT, meaning that only statements that are identical in all respects will be shared among different executions of the statement. Either of the alternative values for the CURSOR_SHARING parameter, FORCE or SIMILAR, ensures Oracle will reuse statements even if they aren t identical in all respects. For example, if two statements are identical in all respects and differ only in literal values for some variables, using CURSOR SHARING=FORCE will enable Oracle to reuse the parsed SQL statements in its library cache. Oracle replaces the literal values with bind values to make the statements identical. The CURSOR_SHARING=FORCE option forces the use of bind variables under all circumstances, whereas the CURSOR SHARING=SIMILAR option does so only when Oracle thinks doing so won t adversely affect optimization. Oracle recommends the use of CURSOR_SHARING=SIMILAR rather than CURSOR_SHARING=FORCE because of possible deterioration in the execution plans. However, in reality, the benefits provided by the CURSOR_SHARING=FORCE parameter far outweigh any possible damage to the execution plans. You can improve the performance of your database dramatically when you notice a high degree of hard parsing due to failing to use bind variables by moving from the default CURSOR_SHARING=EXACT option to the CURSOR_SHARING=FORCE option. You can change the value of this parameter in the init.ora file or SPFILE, or you can do so dynamically by using the ALTER SYSTEM (instance-wide) statement or the ALTER SESSION (session-level) statement. By allowing users to share statements that differ only in the value of the constants, the CURSOR_ SHARING parameter enables the Oracle database to scale easily to a large number of users who are using similar, but not identical, SQL statements. This major innovation started in the Oracle8i version.
Copyright © OnBarcode.com . All rights reserved.