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Locate an interesting error in selecting the Execution Plan (involving SYS_OP_C2) and execute the plan sys_op_c2. These two days and guangfen's brother read a question, which is interesting and the process is tortuous... Symptom: 1. 11g library, say there is a new application launched, the application uses the Bind Variable Method to execute a simple SQL, such as select a from B where c =: x, column c is t

Basic elements (time, user, problem) the user in the 11G environment has a section of SQL statements in the program is very inefficient execution, but in plsql execution is very fast, by looking at the execution plan, found that the use of different indexes caused, the program executes the following:The effects performed in Plsql are as follows:You can see the difference, the use of outpatient expense records _IX_ Registration time index is the execut

After the contract is signed, the main purpose of this phase is to prepare a plan that has obtained the consent of the stakeholders of the main project, which has the correct big framework and can guide the project implementation, further improvement, adjustment and updating of the project plan is a continuous activity in the project implementation process. In addition to having sufficient project experienc

Mo Ge: my business plan, Mo Ge: Business Plan [Mo Ge: 1 million articles per day] A few days ago, Qin da wrote an article titled "Qin Gang: how to write a business plan with sufficient weight". In this article, he suggested that whether you raise funds or not, you should write such a business plan, because it gives you

Oracle Partition Table execution plan, oracle execution plan Partition tables have many advantages: they are big, small, and small. With parallel use, loap can often improve the performance by dozens or even hundreds of times. Of course, poor table design can also be counterproductive, and the effect is worse than that of normal tables. To better use a partitioned table, let's take a look at the execution

5.4pt;mso-para-margin:0cm;mso-para-margin-bottom:.0001pt;mso-pagination:widow-orphan;font-size:10.0pt;font-family:"Times New Roman";mso-fareast-font-family:"Times New Roman";mso-ansi-language:#0400;mso-fareast-language:#0400;mso-bidi-language:#0400;}--> o:spt="75" o:preferrelative="t" path="m@4@5l@4@11@9@11@9@5xe" filled="f" stroked="f"> height:264.75pt'> o:title=""/> The first figure shows the execution plan

Inaccurate MySQL execution plan-Overview, mysql execution plan The execution plan for the Mao MySQL optimizer is often inaccurate, but not optimal (cpu + io )??? Too many factors :: The information of information_schema is regularly refreshed. In many cases, it is not the most authentic, or even the difference is very large (when it is not a mountain peak, make

There are many ways to view execution plans. I will introduce them one by one in my blog in the future. This article describes the first method. You can use the explain plan command to view the execution plan.1. log on to the database with an hr user[Oracle @ ENMOEDU ~] $ Sqlplus hr/oracle @ ENMOEDUSQL * Plus: Release 11.2.0.3.0 Production on Thu Apr 10 00:11:00 2014Copyright (c) 1982,201 1, Oracle. All rig

Framework Plan essay I. Background and vision, Framework Plan essay vision It has been 11 years since I registered my blog. In fact, I forgot how I registered my blog. Afterwards, I never remembered writing my own blog. Recently, I am working on my own architecture plans, and I am gradually guiding the back-up for coding, and I plan to write my own. net-based ORM

Explanation of MySQL execution plan, mysql execution planExplain syntax Explain select ...... Variant: 1. explain extended select ...... Decompile the execution plan into a SELECT statement and run show warnings to obtain the query statement optimized by the MySQL optimizer. 2. explain partitions select ...... Used to EXPLAIN the Partition Table Information contained in the execution

View the Oracle Execution Plan and the oracle execution plan1. PL/SQL explain Plan window Advantages: Disadvantage: limited information2. explain_plan It is easier to optimize a sentence.3. sqlplus Run the following command in Sqlplus: Set autotrace on Select * from emp; After the data is displayed, follow the execution plan: The advantage of this s

,Let's build this one. Index: CREATE index idx_col2_col3 on Teststatistics(col2,col3)Executes a query that is estimated to be 4127.86 rowsThen drop the index above and continue creating an index: Create index idx_col3_col2 on Teststatistics(col3,col2)Note that the order of COL2 and COL3 is inconsistentContinue execution of the above query (the query condition is unchanged, the data is unchanged, only the index column order has changed), this time is estimated to be 2414.91 row Query conditions,

To add, if you want to do a SQL automatic audit tool, where can I start?1, through the Sql*plus tool in the explain PLAN for judgment, the use of Dbms_xplan. Display displays.2, through the Sql*plus tool in the SET autotrace command display3, Sql_trace, in the database global (performance problem, is basically a waste of options), or to the current session definition Sql_trace, or use Dbms_system. Set_sql_trace_in_session gets the sql_trace of the oth