crystal report ean 13 formula STATEMENT CACHING in Font

Printer Code-39 in Font STATEMENT CACHING

CHAPTER 13 STATEMENT CACHING
Generate Code 39 Extended In None
Using Barcode generator for Font Control to generate, create Code39 image in Font applications.
www.OnBarcode.com
Code 128A Encoder In None
Using Barcode maker for Font Control to generate, create Code-128 image in Font applications.
www.OnBarcode.com
The tkprof results for the case when explicit caching was disabled are as follows: select /*+ explicit disabled */ count(*) from dual call count ------- -----Parse 1000 Execute 1000 Fetch 1000 ------- -----total 3000 cpu elapsed disk query current -------- ---------- ---------- ---------- ---------0.30 0.33 0 0 0 0.25 0.23 0 0 0 0.27 0.21 0 0 0 -------- ---------- ---------- ---------- ---------0.82 0.78 0 0 0 rows ---------0 0 1000 ---------1000
GS1 128 Creation In None
Using Barcode encoder for Font Control to generate, create USS-128 image in Font applications.
www.OnBarcode.com
PDF417 Maker In None
Using Barcode generator for Font Control to generate, create PDF-417 2d barcode image in Font applications.
www.OnBarcode.com
Misses in library cache during parse: 0 As expected, we soft-parse the statement 1,000 times. With explicit caching enabled, we parse the statement only once: select /*+ explicit enabled */ count(*) from dual
Creating UPC-A In None
Using Barcode creator for Font Control to generate, create UPC Code image in Font applications.
www.OnBarcode.com
Draw DataMatrix In None
Using Barcode creation for Font Control to generate, create Data Matrix 2d barcode image in Font applications.
www.OnBarcode.com
call count ------- -----Parse 1 Execute 1000 Fetch 1000 ------- -----total 2001
Printing Barcode In None
Using Barcode generation for Font Control to generate, create Barcode image in Font applications.
www.OnBarcode.com
Postnet Maker In None
Using Barcode maker for Font Control to generate, create USPS POSTNET Barcode image in Font applications.
www.OnBarcode.com
cpu elapsed disk query current -------- ---------- ---------- ---------- ---------0.00 0.00 0 0 0 0.16 0.25 0 0 0 0.13 0.15 0 0 0 -------- ---------- ---------- ---------- ---------0.29 0.41 0 0 0
Read Code 39 In None
Using Barcode decoder for Software Control to read, scan read, scan image in Software applications.
www.OnBarcode.com
Code 39 Extended Creation In Java
Using Barcode generator for Java Control to generate, create Code 3 of 9 image in Java applications.
www.OnBarcode.com
rows ---------0 0 1000 ---------1000
Making PDF 417 In None
Using Barcode maker for Software Control to generate, create PDF417 image in Software applications.
www.OnBarcode.com
GS1 - 12 Recognizer In Visual C#
Using Barcode scanner for .NET framework Control to read, scan read, scan image in Visual Studio .NET applications.
www.OnBarcode.com
Misses in library cache during parse: 0 Once again, we reduce the elapsed time to almost half using explicit caching (from 0.79 to 0.42). The following tkprof output for the procedure invocation proves that the anonymous block gets soft-parsed only once due to explicit statement caching in the case of Oracle CallableStatement as well: begin/*+ enabled explicit caching for callable statement */ :1 := f; end; call count ------- -----Parse 1 Execute 1000 Fetch 0 ------- -----total 1001 cpu elapsed disk query current -------- ---------- ---------- ---------- ---------0.00 0.00 0 0 0 2.03 2.06 0 0 0 0.00 0.00 0 0 0 -------- ---------- ---------- ---------- ---------2.03 2.06 0 0 0 rows ---------0 1000 0 ---------1000
GS1 - 12 Reader In Visual Basic .NET
Using Barcode reader for .NET Control to read, scan read, scan image in Visual Studio .NET applications.
www.OnBarcode.com
Code 128 Creator In VS .NET
Using Barcode creation for Reporting Service Control to generate, create Code 128 Code Set A image in Reporting Service applications.
www.OnBarcode.com
Misses in library cache during parse: 0
Decoding Code 128A In Java
Using Barcode reader for Java Control to read, scan read, scan image in Java applications.
www.OnBarcode.com
Encode Data Matrix ECC200 In Visual C#
Using Barcode creator for .NET framework Control to generate, create DataMatrix image in .NET applications.
www.OnBarcode.com
CHAPTER 13 STATEMENT CACHING
Generate Barcode In .NET
Using Barcode maker for Reporting Service Control to generate, create Barcode image in Reporting Service applications.
www.OnBarcode.com
Make Code 39 In Objective-C
Using Barcode maker for iPhone Control to generate, create ANSI/AIM Code 39 image in iPhone applications.
www.OnBarcode.com
Caution When you retrieve an explicitly cached statement, make sure you use the method that matches your statement type when specifying the key that is, use getStatementWithKey() for PreparedState ment and getCallWithKey() for CallableStatement. Otherwise, you may get unexpected results, such as a NullPointerException.
Decoding QR Code JIS X 0510 In None
Using Barcode scanner for Software Control to read, scan read, scan image in Software applications.
www.OnBarcode.com
Encoding Barcode In Java
Using Barcode creator for Android Control to generate, create Barcode image in Android applications.
www.OnBarcode.com
Implicit Caching vs. Explicit Caching
Table 13-1 summarizes the differences between implicit and explicit caching. Note that the assertion related to performance difference will be proved later in this section. Table 13-1. Differences Between Implicit and Explicit Statement Caching
Implicit Statement Caching
Designed to transparently enable caching in an entire application and then selectively disable it for infrequently used statements. Supports PreparedStatement and CallableStatement. Your code for executing statements does not change only the portion of the code that retrieves the connection for your application changes when you enable implicit statement caching.
Explicit Statement Caching
Designed to explicitly enable caching for specific statements. Supports Statement, PreparedStatement, and CallableStatement, although this is not a real advantage since you should mostly avoid using the Statement interface in production code anyway. Enabling explicit statement caching also introduces changes in the code that executes statements. This is because you need to supply the cache key, and you need to use Oracle extension methods that end with WithKey. Methods used are getStatementWithKey() for Statement or PreparedStatement objects, and getCallWithKey() for CallableStatement objects. During explicit statement caching, if the JDBC driver cannot find a statement in cache, it will return null; you have to check for null and create a statement yourself. Retains statement data and state as well as metadata, hence it has a slight performance edge over implicit statement caching, which retains only metadata. In my tests, though, I could not find any material performance differences between the two caching mechanisms.
Methods used are prepareStatement() or prepareCall(), depending on whether you want to cache PreparedStatement or CallableStatement. To cache the statement, use the standard method close() on the statement. During implicit statement caching, if the JDBC driver cannot find a statement in the cache, it will automatically create one. Retains only the statement metadata, hence it runs slightly slower than explicit statement caching.
As promised, we will compare the performance of explicit caching with implicit caching. We will only do the comparison for PreparedStatement. The following class compares the performance of implicit statement caching with that of explicit statement caching for a simple
Copyright © OnBarcode.com . All rights reserved.