1. Explain extendedselect... decompile the execution plan into a SELECT statement and run showwarnings to obtain the query statement optimized by the MYSQL optimizer. 2. explainpartitionsselect... information contained in the explain execution plan of the partitioned table idselect_typetabletypepossible_keyskey
1. explain extended select... decompile the execution plan
Linux shell script to adjust the task plan
There are 2 scripts to run the task plan every day
Dts_rsync.sh downloads online backup SQL files
Dts_input.sh is responsible for importing the downloaded backup file to the local Mysql
One problem is that the backup file download time is not fixed. In the past, the download was completed at a.m., and now it can be completed at a.m.. It may be added later.
The down
Create a Dial plan
To create a new dial plan, follow the steps in the following procedure. If you are editing a dial plan, see Modify a dial plan.
Create a Dial plan
1. Log on to the computer as a member of the RTCUniversalServerAdmins group or as a member of the Csvoicea
Both EXPLAIN plan and AUTOTRACE can view the execution plan. It is worth mentioning that the former is only the optimizer by reading the statistics of the data dictionary to make the ' best ' access path judgment, and does not really go to execute the statement , the latter is actually to execute the SQL statement, while the number of access records, execution plan
Tags: blog http ar os sp strong file data onOriginal: Database backup of "MS SQL" Database maintenance plan (II)Database backup of the "MS SQL" Database Maintenance plan (a) after some concept of database backup, this article takes the HRP_KQYY database backup as an example to set up the backup schedule.Considering factors such as time of backup, performance, and hard disk space, the backup scenario is set
This article follows: SQL Server execution Plan operator detailed (1)-Assertion (Assert)Objective:According to the plan, this article began to tell the other operator concatenation (concatenation), the reader can be based on the word (both English and Chinese) first fantasy is what it is. In fact, it is very intuitive, is to connect things together, then let us look at the bottom of what even? How do you ev
Preface:
This series of articles includes:
1, understand the hash, Merge, Nested Loop Association strategy.
2. Find and resolve table/index scans in the execution plan.
3. Introduce and find keys to find and resolve them in the execution plan.
For performance optimization, the following issues need to be centrally addressed:
1, create a performance baseline for your environment.
2, monitor the current per
How to read ORACLE Execution Plan
First, what is the implementation plan
An explain plan is a representation of the "access path" is taken when a query is executed within Oracle.
second, how to access data
At the physical level Oracle reads blocks of data. The smallest amount of data read is a single Oracle block, the largest are constrained by operating syste
Add UserThe first step you want to do every JMeter test plan is to add a Thread Group element. The thread group tells JMeter the number of users you want to impersonate, how long the user should send the request, and how many requests they should send. continue adding Threadgroup elements first select the test plan, click your right mouse button Add a menu, then choose add a?? threadgroup . You should n
SQL Server maintenance plan for database backup (step by Step)First, PrefaceSQL Server Backup and restore all -in-a-kind, including the use of SSMS operation to restore a variety of backup files graphical guidance,SQL Server Database Minimum outage migration scenario , which uses SQL script (T) to complete a full backup, Differential backup, full restore, differential restore, etc.; with the above foundation, we joined the database backup elements, th
Guidance:Like Oracle databases,DB2 databaseThe optimizer is also used to analyze your SQL statements and generate the statements that are optimal.Execution Plan(Access Plan ). The DB2 optimizer is actually a set of standard rules. Generally, we only need to tell DB2 what to search, not how to search.
So what is the DB2 optimizer used to determine the optimal SQL access path?
DB2 optimizer is a Cost-Based op
Oracle Partition Table 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 plan of the partitioned
The oracle execution plan storage outline corresponds to the SQL statement one by one. Therefore, if we change the predicate condition in the SQL statement, the storage outline will be ineffective or we need to create a new storage outline to consolidate the execution plan. To avoid this, we can use variables to replace text information.
Without binding variables:
SQL> show userUSER is "EASY1" SQL> select *
The execution plan shows COLLECTIONITERATORPICKLERFETCH
Collection iterator pickler fetch appears in the execution plan
Today, when I used explain plan for to view the SQL Execution plan, the following strange execution plan appeared:
After troubleshooting, it is fou
It career planning: Easy to say
Do you want a career plan? How? Why are you confused about career planning? Many people have these questions.
In fact, many large companies now have career plans, which allow each employee to set their careers, set their work goals, and perform year-end assessments. Most small companies do not have career plans for employees. Do we need to make a career plan? The answer is y
According to IEEE 828 and CMM/cmme, A Configuration Management Plan is often considered a document. Indeed, for a large project, it is often necessary to develop a configuration management plan of the project.But not all organizations are software outsourcing organizations, and not every project targets different customers.In an efficient software development organization that does not outsource software, t
Test Environment Simulation:SQL> drop table t_col_type purge;Create Table t_col_type (ID varchar2 (20), col2 varchar2 (20), col3 varchar2 (20 ));Insert into t_col_type select rownum, 'abc', 'efg' from dual connect by level Commit;Create index idx_id on t_col_type (ID );Set linesize 1000Set autotrace traceonlydrop table t_col_type purge*Error at line 1:ORA-00942: Table or view does not exist
SQL> select * From t_col_type where id = 6;
Execution Plan--
. if the stream data cannot be separated from the database, you can consider Table partitions and then back up the data of other tables (primary partition backup) After partitioning. These backups cannot use differential backup, only full backup can be used each time, and table partitions cannot be used during restoration. You can only change the table name and create a new table. For details, refer to: SQL Server maintenance plan to back up the prima
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