drawing views

Label:Excerpt from: http://www.cnblogs.com/yjf512/p/4402096.html The view in Postgres scans the sub-table when it is queried, while materialized views actually save the data in a single table. Materialized views are something that is only after 9.3. Create a View CREATE OR REPLACE VIEW student_view asselect *from student left JOIN teacher on= teacher.id; Create a materialized view CREATE

.----------------------------------------------------------------------------------------------------------- ---------------------Dba_segments describes the storage allocated for all segments in the database. Related View user_segments describes the storage allocated for the segments owned by the current USER ' s objects. This view does not display the OWNER, Header_file, Header_block, or relative_fno columns.　　The dba_segments view describes the storage and allocation information for all segme

--Get the current value of the sequence select Sq_test.nextval from dual; --Remove a value select Sq_test.currval from dual; --Current value insert into T_user values (Sq_test.nextval, ' Zhang San ' | | sq_test.currval); commit;---view select * from V_score;----Index Select T.sname from student t where sname= ";--physical attempt to select T.*, t.rowid from mv_test t--Call stored Procedure--Refresh physical view exec DBMS_MVIEW.REFRESH_MV (' Mv_test '); --This statement needs to be executed

PrefaceAn excellent application is not only to have attractive features and interactions, but also to have high performance requirements. Mobile phone running Android system, although the configuration in the continuous upgrade, but still can not be compared with the PC, the PC does not have the same large memory and high-performance CPU, so in the development of Android applications can not be unlimited use of CPU and memory, Improper use of CPU and memory can also cause problems such as applic

host's RRD files are placed in a textfolder, the folders are named after the host ID, each RRD file is named with a graphics ID and with the. rrd suffix, each rrd file's DS is named with Itemid. This will make it possible to find the data correctly.The source. Once you have solved these logical problems, you can heap the drawing code. First locate the RRD file you want to draw based on the HostID and type of the GET request Rrdtooldraw02 The func

can use method colorwithalphacomponent to create a translucent color.If you use transparency when drawing, you need to tell the system to set the UIView opaque property to False. Why did you do it? Because transparency is very expensive to draw, because the view behind you is displayed, the system must mix the overlapping views to draw, which is very expensive in the image processing power. So if it is not

programming. Cgpoint, cgsize, cgrect definition: struct CGPoint { float x; float y; }; struct CGSize { float width; float height; }; struct CGRect { CGPoint origin; CGSize size ; }; (2) The Coordinate System Origin of the view is in the upper left corner. Increasing X to the right and adding Y to the right is upward. (3) Coordinate units are points rather than pixels. A vertex is a graphical term. A property in uiview is contentscalefactor, whic

Python chart drawing: Getting Started with the Matplotlib drawing library Matplotlib is Python's most famous drawing library, which provides a complete set of command APIs similar to MATLAB, and is ideal for interactive line drawing. It can also be conveniently embedded in GUI applications as a

Matplotlib is Python's most famous drawing library, which provides a complete set of command APIs similar to those of MATLAB, and is ideal for interactive line mapping. It can also be easily used as a drawing control, embedded in GUI applications.Its documentation is quite complete, and there are hundreds of thumbnails on the gallery page, and the source program opens. So if you need to draw some kind of di

Windows form. Net Framework Drawing Technology,. net drawing When writing a typical Windows form program,Drawing forms and controls, Effect and other operations do not need to be taken into consideration. Why? Because. NetFramework, developers can drag a series of controls to the form, write some simple code associated with the event, and then press F5 In the IDE

The purpose of this paper is to introduce some fine operation of Ggplot2 package in R language, which is mainly applicable to people who have a certain understanding of R-Drawing and need to be more finely transformed into diagrams, especially those who have just turned ggplot2 from Excel, and have more frequent drawing needs. No discussion of those very cool charts, with practical commercial charts as the

Double-buffered plotting analysis1. Principles of Windows DrawingWe see various elements in the Windows environment, such as menus, buttons, windows, images, which are basically "painted". At this point, the screen is equivalent to a blackboard, and the various GDI elements under Windows, such as brushes, brush, etc., are equivalent to colored chalk. When we hand-draw on the blackboard, it is a stroke, and so is the computer. It's just that the speed of the computer is much faster than the manua

PHP Drawing is a relatively simple thing, basic drawings such as lines, circles, rectangles, arcs, filled rectangles, filled fan, non-Chinese text printing, Chinese text printing in the code below will be a slender explanation.Need to support Chinese fonts, can be found in the Windows own font library, and copied to the current directory, renamed to Font.ttf1PHP2 //1. Create a canvas3 $im=imagecreatetruecolor (500,400);4 //2. Create a colo

Summary of some functions of drawing images in PHP, PHP drawing image function The function of drawing images in PHP is very rich, including points, lines, various geometries and other conceivable plane graphics, can be done by the various drawing functions provided in PHP. We are here to introduce some of the commonl

The current CPU is very fast, in fact, the mathematical computing is generally very fast, the CPU is processing the drawing most of the time, and the drawing has three realms: 1> Each redraw the overall invalidate (); 2> invalidate (rect) is drawn locally each time. 3> selected partial painting is available. It cannot be said that the third method is good, depending on the situation, the realm is highProg

(7/18) re-learn Standford_iOS7 development _ views, plotting, gesture recognition _ course notes, standford_ios7 gestures Lesson 7: 1. View Generally, a view is a construction block that represents a rectangular area on the screen, defines a coordinate space, and draws and adds touch events. ① Hierarchical relationship of views A view can have only one parent view and multiple child

different frames:It makes sense that after we change the button's frame.origin, it changes its position relative to the purple parent view. Note that if we move the button until part of it is already outside of the purple parent view bounds, this part will be truncated by the same drawing mode when the rasterized picture is truncated. However, technically, you can render a child view outside the bounds of its parent view because of the reason that IO

Note: I am a translator, and add a bit of my opinion. Objective You may find it hard to believe that Uiscrollview and a standard UIView difference is not very big, scroll view does have a few more methods, but these methods are just a good combination of UIView properties. Therefore, before you can understand how Uiscrollview works, you need to understand the UIView, especially the two-step process of view rendering. Directory 1. Rasterization and Combination2. Scroll View's Contentoffset3. Win

Using system;using system.collections.generic;using system.componentmodel;using system.data;using System.Drawing; Using system.linq;using system.text;using system.windows.forms;namespace instance 7_7 drawing graphics {public partial class Firstform:fo RM {public Firstform () {InitializeComponent (); } private void Button1_Click (object sender, EventArgs e) {Form1 f1 = new Form1 (); F1. Show (); } private void Button

OverviewThis article implements the following program: ( drawing text in a form )The main steps are as follows:1. Create a new project in Eric6, create a new form2, (automatically open) into PyQt5 Desinger, edit the GUI, save3, back to Eric 6, to the previous step to get the interface file Drawing.ui file right-click, compile the form, get ui_drawing.py file4, then right-click on the Drawing.ui file, generate dialog code, get drawing.py file. ( add yo