at t roaming plans

, regardless of whether the specified value has only one data. The estimated results are all 99.0099, which indicates that the estimate does not take into account the values we specify.Further testing with variables ALTER INDEX ix_c on _t REBUILD;GO SET showplan_all onGODECLARE @v varchar; SELECT * from _t WHERE c = @v; --varcharGO SET showplan_all OFF;GO ALTER INDEX ix_c on _t REBUILD;GO SET showplan_all onGODECLARE @nv nvarchar; SELECT * from _t WHERE c = @nv; --nvarcharGO SET showpla

affect performance, 0 or 1 This identifies the status of the field because most of the data is the same index does not make any difference(Two indexes, 1 is a clustered index, 2 nonclustered indexes, a clustered index can have only one per table, a nonclustered index each table may have more than one, the primary key ID is a typical clustered index, the clustered index is similar to the dictionary lookup pinyin A, B, c ...) and the dictionary text content order is the same, the nonclustered ind

each step succeeds or fail, and finally select the step to begin with. In the Schedule tab, a maintenance plan that resembles a backup, filling out the scheduling cycle, which is the periodic cleanup cycle, is no longer detailed.If necessary, you can set the notification item after the job is completed on the last Notification tab, set up the operator, and set up the appropriate service, which is not specified here, usually not ... Originally are manually performed above the various operations,

defined, records in the table are displayed in the order in which they are entered. The primary key features: Uniqueness, non-nullability. Example of setting a primary KEY statement: Code int PRIMARY key, primary key cannot be empty, cannot be duplicated, ensures uniqueness Example of setting a self-growing primary KEY statement: The code int primary Key identity ( 1) starts at 1 each time , adding values you do not need to add this column To set a foreign key: Right-click on the table wh

(Dbms_xplan.display_cursor (null,0, ' allstats last '));The Dbms_xplan.display_cursor function is defined as:--Display from V$sql_plan (or V$sql_plan_statistics_all)function Display_cursor (sql_id varchar2 default NULL,Cursor_child_no integer default 0,Format varchar2 default ' typical ')Return dbms_xplan_type_tablepipelined;Where the parameter sql_id is the parent cursor, or NULL, indicates the SQL execution plan before the session is displayed. Cursor_child_no is the ordinal of a child cursor

According to foreign media reports, the company plans to shut down its 2G network in 2017 due to the impact of ATT Mobility's redistribution of 2G network spectrum and deployment of more advanced services. The US telecom operator is now re-deploying its 1900 MHz PCS spectrum in New York City to switch Global Mobile Communication System services to HSPA + and LTE services. The company disclosed in a file submitted to the Securities and Exchange Commis

In December 27, MarkShuttleworth, founder of the well-known Linux system Ubuntu, recently shared his plans for Ubuntu in 2013. Shuttleworth said that while maintaining the old version of Ubuntu, they also hope to explore unfamiliar and uncertain fields, such as mobile platforms and the cloud, in ldquo. Next year, the development of Unity (Ubuntu Desktop Environment) will be fully centered on the mobile platform, and the Ubuntu In December 27, Mark S

Ubuntu plans to remove the notification area on the taskbar, because statistics show that the notification area reminders are of little use and often disturb user operations. Ubuntu developers have been asked to use other methods such as status messages or dialog boxes to remind users, and the notification area will display the system menu and status information. We don't know whether the change is good or bad, but the design is inspired by Windows. T

affect the performance. Therefore, use it with caution.--------------------------------------------------------------------------------Most of the information collected by the two methods is the same. The XML method returns the results in XML structure. In SQL Trace, the results can display the execution plan and related information graphically.This output method may be more friendly for simple statements in execution plans. However, for complex exec

Oracle Database how to collect specific SQL Execution Plan and solve the ORA-00904 errors in the process (copyright statement, I Original or translated articles if you need to reprint, such as reproduced for personal learning, please indicate the source; otherwise, contact me. The attacker must know) how to collect the execution plan of the specified SQL statement is very important for developers. Here, the basic collection is recorded. Oracle Database how to collect specific SQL Execution Plan

: This article mainly introduces 30 + programmers. what do you usually do? What do you usually think? What plans will be made in the future ?, If you are interested in the PHP Tutorial, refer. Many people say that after the age of 30, is there a future for writing programs? I am also confused sometimes, but after I am confused, I will always look for directions for myself. everyone needs to have a belief and no belief. if I live, I am boring and don't

-- Obtain the SQL Execution Plan and statistics without displaying the Query Information SQLgt; setautotracetraceonly; SQLgt; select * fromtest; Execution Plan ----- -- Obtain the SQL Execution Plan and statistical information, without displaying the Query Information SQLgt; set autotrace traceonly; SQLgt; select * from test; Execution Plan ----- Homepage → Database Technology Background:Read News View SQL Execution plans and stati

already the center of gravity of ESRI, how could it not be exerting its force on this? Especially 3D this piece, big data this piece, cloud computing this piece.My AJS Study notes directoryEasy to access, click on the jump.ArcGIS API for JavaScript 4.2 learning notes [0] AJS4.2 Overview, new features, future product line plans and AJS notes directoryArcGIS API for JavaScript 4.2 Learn notes [1] Show MapArcGIS API for JavaScript 4.2 study notes [2] Sh

Reprint Please specify source: http://blog.csdn.net/caoyouxing/article/details/42490173Making New Year Plans is one of our favorite things to do, and we always have a good plan for the new Year at the end, but then we put them all behind us until we finally forget them all. Perhaps, our plan is always too grand, a lot of things can not be done, even seems to be out of reach. However, this year will certainly be different, this article is designed for

Since 1979, Unix-like systems have adopted a special method, which may be obscure to some people-to organize files. Now, if you can overcome various potential challenges, the Linux ora project plans to change the file system hierarchy for storing binary applications. RedHat developers HaraldHoyer and KaySievers propose to move all executable files into the/usr/bin directory and move their libraries to/usr/lib or/usr/lib64 as needed. Author of systemd

At plans to run commands and Program . The at command can only be used when the "scheduler" service is running. If you use it without parameters, at lists the scheduled commands. SyntaxAt [\ computername] [{[ID] [/delete] |/Delete [/Yes]}] At [[\ computername] hours: minutes [/interactive] [{/every: Date [,...] |/next: Date [,...]}] command] Parameters\ ComputernameSpecify a remote computer. If this parameter is omitted, the at program

Openxc:any updates on plans for IOS?Hi Thomas,We ' re actively investigating this as we ' d love to able to support all platforms,But I can ' t say for sure what would be possible or when yet.Actually, this would is a great place for some help and advice from the community.Is there any IOS experts in the group?What does think would need to happen and make the OPENXC vehicle interface compatible with IOS?Namely, these is the problems and questions we h

Win8 the method for enabling additional power plans in the system is as follows: 1, right click on the desktop space, under the desktop pop-up "All applications" option, left click "All applications." 2, left click "Control Panel". 3, the second way into the "Control Panel" method. Press the Windows and X keys on the keyboard simultaneously, and click Control Panel. 4, the upper-right corner of the "view mode" c

The impact of indexes and Null values on Hints and execution plans because B * Tree indexes do not store Null values, some Oracle queries are allowed when the index field is Null.If you do not use Index. www.2cto.com many times, it seems that you can use Full Index Scan.The index is dropped because the Null value exists. in this case, Oracle does not use indexes even if Hints is used. The root cause is the existence of Null values. let's take a look a

Create a stored procedure for quick display of Oracle execution plans first: use the default [SQL] www.2cto.com SQL> create or replace procedure SQL _explain (v_ SQL varchar2) without setting output format parameters) 2 is 3 type explain_cursor_type is ref cursor; 4 explain_cursor explain_cursor_type; 5 a varchar2 (2048); 6 begin 7 execute immediate 'explain plan for '| v_ SQL; 8 open explain_cursor for select PLAN_TABLE_OUTPUT from table (dbms_xplan.