barcode font for crystal report REDO AND UNDO in Font

Make DataMatrix in Font REDO AND UNDO

CHAPTER 9 REDO AND UNDO
ECC200 Printer In None
Using Barcode printer for Font Control to generate, create Data Matrix image in Font applications.
www.OnBarcode.com
Generate Data Matrix 2d Barcode In None
Using Barcode drawer for Font Control to generate, create DataMatrix image in Font applications.
www.OnBarcode.com
Re-create the log files with a larger size. This will extend the amount of time between the time you fill the online redo log and the time you need to reuse it. The same applies to the Archival required message, if the redo log file usage is bursty. If you have a period of massive log generation (nightly loads, batch processes) followed by periods of relative calm, then having larger online redo logs can buy enough time for ARCH to catch up during the calm periods. The pros and cons are identical to the preceding approach of adding more files. Additionally, it may postpone a checkpoint from happening until later, since checkpoints happen at each log switch (at least), and the log switches will now be further apart. Cause checkpointing to happen more frequently and more continuously. Use a smaller block buffer cache (not entirely desirable) or various parameter settings such as FAST_START_MTTR_TARGET, LOG_CHECKPOINT_INTERVAL, and LOG_CHECKPOINT_TIMEOUT. This will force DBWR to flush dirty blocks more frequently. The benefit to this approach is that recovery time from a failure is reduced. There will always be less work in the online redo logs to be applied. The downside is that blocks may be written to disk more frequently if they are modified often. The buffer cache will not be as effective as it could be, and it can defeat the block cleanout mechanism discussed in the next section. The approach you take will depend on your circumstances. This is something that must be fixed at the database level, taking the entire instance into consideration.
Barcode Encoder In None
Using Barcode maker for Font Control to generate, create Barcode image in Font applications.
www.OnBarcode.com
Generating ANSI/AIM Code 128 In None
Using Barcode generation for Font Control to generate, create Code 128C image in Font applications.
www.OnBarcode.com
Block Cleanout
Paint Code39 In None
Using Barcode creation for Font Control to generate, create USS Code 39 image in Font applications.
www.OnBarcode.com
Making EAN13 In None
Using Barcode encoder for Font Control to generate, create European Article Number 13 image in Font applications.
www.OnBarcode.com
In this section, we ll discuss block cleanouts, or the removal of locking -related information on the database blocks we ve modified. This concept is important to understand when we talk about the infamous ORA-01555: snapshot too old error in a subsequent section. If you recall in 6, we talked about data locks and how they are managed. I described how they are actually attributes of the data, stored on the block header. A side effect of this is that the next time that block is accessed, we may have to clean it out in other words, remove the transaction information. This action generates redo and causes the block to become dirty if it wasn t already, meaning that a simple SELECT may generate redo and may cause lots of blocks to be written to disk with the next checkpoint. Under most normal circumstances, however, this will not happen. If you have mostly small- to medium-sized transactions (OLTP), or you have a data warehouse that performs direct path loads or uses DBMS_STATS to analyze tables after load operations, then you ll find the blocks are generally cleaned for you. If you recall from the earlier section titled What Does a COMMIT Do one of the steps of COMMIT-time processing is to revisit our blocks if they are still in the SGA, if they are accessible (no one else is modifying them), and then clean them out. This activity is known as a commit cleanout and is the activity that cleans out the transaction information on our modified block. Optimally, our COMMIT can clean out the blocks so that a subsequent SELECT (read) will not have to clean it out. Only an UPDATE of this block would truly clean out our residual transaction information, and since the UPDATE is already generating redo, the cleanout is not noticeable. We can force a cleanout to not happen, and therefore observe its side effects, by understanding how the commit cleanout works. In a commit list associated with our transaction, Oracle will record lists of blocks we have modified. Each of these lists is 20 blocks long, and Oracle will allocate as many of these lists as it needs up to a point. If the sum of the
QR-Code Creator In None
Using Barcode creator for Font Control to generate, create QR-Code image in Font applications.
www.OnBarcode.com
Encoding ISSN - 10 In None
Using Barcode creator for Font Control to generate, create International Standard Serial Number image in Font applications.
www.OnBarcode.com
DataMatrix Reader In Java
Using Barcode scanner for Java Control to read, scan read, scan image in Java applications.
www.OnBarcode.com
Paint ECC200 In .NET
Using Barcode encoder for ASP.NET Control to generate, create DataMatrix image in ASP.NET applications.
www.OnBarcode.com
Drawing Barcode In Objective-C
Using Barcode drawer for iPhone Control to generate, create Barcode image in iPhone applications.
www.OnBarcode.com
Make Linear Barcode In Visual Studio .NET
Using Barcode encoder for ASP.NET Control to generate, create Linear image in ASP.NET applications.
www.OnBarcode.com
Barcode Drawer In .NET
Using Barcode printer for Visual Studio .NET Control to generate, create Barcode image in VS .NET applications.
www.OnBarcode.com
Painting Code 128B In C#
Using Barcode drawer for Visual Studio .NET Control to generate, create Code 128 Code Set C image in Visual Studio .NET applications.
www.OnBarcode.com
EAN13 Scanner In VS .NET
Using Barcode recognizer for .NET framework Control to read, scan read, scan image in VS .NET applications.
www.OnBarcode.com
Make PDF-417 2d Barcode In Java
Using Barcode printer for Java Control to generate, create PDF 417 image in Java applications.
www.OnBarcode.com
2D Printer In C#.NET
Using Barcode printer for .NET framework Control to generate, create Matrix image in .NET applications.
www.OnBarcode.com
UCC.EAN - 128 Maker In Java
Using Barcode creator for Eclipse BIRT Control to generate, create GS1-128 image in Eclipse BIRT applications.
www.OnBarcode.com
Decoding QR Code 2d Barcode In VB.NET
Using Barcode decoder for .NET Control to read, scan read, scan image in .NET framework applications.
www.OnBarcode.com
QR Code 2d Barcode Encoder In Java
Using Barcode generation for Java Control to generate, create QR Code ISO/IEC18004 image in Java applications.
www.OnBarcode.com
Copyright © OnBarcode.com . All rights reserved.