native barcode generator for crystal reports crack DATABASE TABLES in Objective-C

Generator Data Matrix 2d barcode in Objective-C DATABASE TABLES

CHAPTER 10 DATABASE TABLES
Data Matrix ECC200 Creator In Objective-C
Using Barcode creation for iPhone Control to generate, create DataMatrix image in iPhone applications.
www.OnBarcode.com
Making QR Code JIS X 0510 In Objective-C
Using Barcode creator for iPhone Control to generate, create QR Code JIS X 0510 image in iPhone applications.
www.OnBarcode.com
Note LOB data that is stored out of line in the LOB segment does not make use of the PCTFREE/PCTUSED
Barcode Encoder In Objective-C
Using Barcode maker for iPhone Control to generate, create Barcode image in iPhone applications.
www.OnBarcode.com
Generating Code 39 Extended In Objective-C
Using Barcode drawer for iPhone Control to generate, create Code-39 image in iPhone applications.
www.OnBarcode.com
parameters set for the table. These LOB blocks are managed differently: they are always filled to capacity and returned to the FREELIST only when completely empty.
Encoding Code 128A In Objective-C
Using Barcode generator for iPhone Control to generate, create Code 128 Code Set A image in iPhone applications.
www.OnBarcode.com
Barcode Encoder In Objective-C
Using Barcode generator for iPhone Control to generate, create Barcode image in iPhone applications.
www.OnBarcode.com
These are the parameters you want to pay particularly close attention to. With the introduction of locally managed tablespaces, which are highly recommended, I find that the rest of the storage parameters (such as PCTINCREASE, NEXT, and so on) are simply not relevant anymore.
Encoding ECC200 In Objective-C
Using Barcode maker for iPhone Control to generate, create ECC200 image in iPhone applications.
www.OnBarcode.com
EAN8 Creator In Objective-C
Using Barcode printer for iPhone Control to generate, create EAN 8 image in iPhone applications.
www.OnBarcode.com
Index Organized Tables
Data Matrix ECC200 Generation In Visual Studio .NET
Using Barcode drawer for Visual Studio .NET Control to generate, create Data Matrix 2d barcode image in Visual Studio .NET applications.
www.OnBarcode.com
Data Matrix ECC200 Drawer In Java
Using Barcode creator for Java Control to generate, create DataMatrix image in Java applications.
www.OnBarcode.com
Index organized tables (IOTs) are quite simply tables stored in an index structure. Whereas a table stored in a heap is unorganized (i.e., data goes wherever there is available space), data in an IOT is stored and sorted by primary key. IOTs behave just like regular tables do as far as your application is concerned; you use SQL to access them as normal. They are especially useful for information retrieval, spatial, and OLAP applications. What is the point of an IOT You might ask the converse, actually: what is the point of a heap organized table Since all tables in a relational database are supposed to have a primary key anyway, isn t a heap organized table just a waste of space We have to make room for both the table and the index on the primary key of the table when using a heap organized table. With an IOT, the space overhead of the primary key index is removed, as the index is the data, and the data is the index. The fact is that an index is a complex data structure that requires a lot of work to manage and maintain, and the maintenance requirements increase as the width of the row to store increases. A heap, on the other hand, is trivial to manage by comparison. There are efficiencies in a heap organized table over an IOT. That said, IOTs have some definite advantages over their heap counterparts. For example, I once built an inverted list index on some textual data (this predated the introduction of interMedia and related technologies). I had a table full of documents, and I would parse the documents and find words within them. My table looked like this: create table keywords ( word varchar2(50), position int, doc_id int, primary key(word,position,doc_id) ); Here I had a table that consisted solely of columns of the primary key. I had over 100 percent overhead; the size of my table and primary key index were comparable (actually, the primary key index was larger since it physically stored the rowid of the row it pointed to, whereas a rowid is not stored in the table it is inferred). I only used this table with a WHERE clause on the WORD or WORD and POSITION columns. That is, I never used the table I used only the index on the table. The table itself was no more than overhead. I wanted to find all documents containing a given word (or near another word, and so on). The KEYWORDS heap table was useless, and it just slowed down the application during maintenance of the KEYWORDS table and doubled the storage requirements. This is a perfect application for an IOT. Another implementation that begs for an IOT is a code lookup table. Here you might have ZIP_CODE to STATE lookup, for example. You can now do away with the heap table and just use an IOT itself. Anytime you have a table that you access via its primary key exclusively, it is a possible candidate for an IOT.
Painting PDF-417 2d Barcode In Java
Using Barcode maker for Android Control to generate, create PDF-417 2d barcode image in Android applications.
www.OnBarcode.com
Painting Barcode In .NET Framework
Using Barcode printer for Reporting Service Control to generate, create Barcode image in Reporting Service applications.
www.OnBarcode.com
CHAPTER 10 DATABASE TABLES
Barcode Maker In None
Using Barcode creator for Microsoft Word Control to generate, create Barcode image in Word applications.
www.OnBarcode.com
Generate Barcode In Java
Using Barcode printer for Java Control to generate, create Barcode image in Java applications.
www.OnBarcode.com
When you want to enforce co-location of data or you want data to be physically stored in a specific order, the IOT is the structure for you. For users of Sybase and SQL Server, this is where you would have used a clustered index, but IOTs go one better. A clustered index in those databases may have up to a 110 percent overhead (similar to the previous KEYWORDS table example). Here, we have a 0 percent overhead since the data is stored only once. A classic example of when you might want this physically co-located data would be in a parent/child relationship. Let s say the EMP table had a child table containing addresses. You might have a home address entered into the system when the employee is initially sent an offer letter for a job. Later, he adds his work address. Over time, he moves and changes the home address to a previous address and adds a new home address. Then he has a school address he added when he went back for a degree, and so on. That is, the employee has three or four (or more) detail records, but these details arrive randomly over time. In a normal heap based table, they just go anywhere. The odds that two or more of the address records would be on the same database block in the heap table are very near zero. However, when you query an employee s information, you always pull the address detail records as well. The rows that arrive over time are always retrieved together. To make the retrieval more efficient, you can use an IOT for the child table to put all of the records for a given employee near each other upon insertion, so when you retrieve them over and over again, you do less work. An example will easily show the effects of using an IOT to physically co-locate the child table information. Let s create and populate an EMP table: ops$tkyte%ORA11GR2> create table emp 2 as 3 select object_id empno, 4 object_name ename, 5 created hiredate, 6 owner job 7 from all_objects 8 / Table created. ops$tkyte%ORA11GR2> alter table emp add constraint emp_pk primary key(empno) 2 / Table altered. ops$tkyte%ORA11GR2> begin 2 dbms_stats.gather_table_stats( user, 'EMP', cascade=>true ); 3 end; 4 / PL/SQL procedure successfully completed. Next, we ll implement the child table two times, once as a conventional heap table and again as an IOT: ops$tkyte%ORA11GR2> create table heap_addresses 2 ( empno references emp(empno) on delete cascade, 3 addr_type varchar2(10), 4 street varchar2(20), 5 city varchar2(20), 6 state varchar2(2), 7 zip number,
Drawing Barcode In Java
Using Barcode creation for Java Control to generate, create Barcode image in Java applications.
www.OnBarcode.com
Barcode Generator In Java
Using Barcode generation for Java Control to generate, create Barcode image in Java applications.
www.OnBarcode.com
GTIN - 13 Generation In Java
Using Barcode drawer for BIRT Control to generate, create UPC - 13 image in BIRT applications.
www.OnBarcode.com
Draw 2D Barcode In Java
Using Barcode generator for Java Control to generate, create 2D image in Java applications.
www.OnBarcode.com
Create QR Code In Visual C#
Using Barcode printer for .NET Control to generate, create Quick Response Code image in .NET framework applications.
www.OnBarcode.com
Code 128 Encoder In Visual Studio .NET
Using Barcode drawer for Reporting Service Control to generate, create USS Code 128 image in Reporting Service applications.
www.OnBarcode.com
Copyright © OnBarcode.com . All rights reserved.