compare at t plans

Tags: style blog http color using OSDbms_xplan.display_cursor definition:function Display_cursor (sql_id varchar2 default NULL,Cursor_child_no integer default 0,Format varchar2 default ' typical ')Return dbms_xplan_type_tablepipelined;Identify problem SQL We can get it in the following ways:1. AWR2. ASH3. Find the corresponding SQL based on the process of high CPU usage at that timeThe problem SQL is found, and then we want to look at the SQL execution plan, but the question is, if you quickly f

here indicates that the optimizer considers the cost of the execution plan:Select statement Optimizer = CHOOSE (Cost = 1234 Card = 1 Bytes = 14) However, if the information shown in the execution plan is similar to the following, it indicates that the RBO optimizer is used because the value of the cost part is null or there is no cost part at all.Select statement Optimizer = CHOOSE Cost =Select statement Optimizer = CHOOSEIn this way, we can find out the Optimizer used to execute the statement

Server Maintenance plans that are automatically performed on a regular basis: Rebuilds the index with the new fill (duty) factor to reorganize the data on the data and index pages. This ensures that database pages contain equally distributed data and remaining space, which allows for faster growth in the future. Remove an empty data page from the database page to compress the data file. Update index statistics to ensure that query optimization has tab

optimization | statement | execution 5th. Oracle's execution planbackground knowledge: To better carry out the following, we must understand some conceptual terms: 　　 Sharing SQL statementsIn order not to parse the same SQL statement repeatedly (because parsing operations cost resources, resulting in performance degradation), after the first parsing, Oracle stores SQL statements and parsed execution plans in memory. This memory in the shared buffer po

Obtain SQL statement execution plans from the most authoritative Oracle Database This document is compiled and summarized based on relevant information. It mainly describes the most authoritative and correct methods and steps for obtaining SQL statement execution plans in Oracle databases. In addition, the meanings and usage of options in each method are also described in detail to facilitate your reference

ORACLE displays SQL statements with multiple execution plans, oraclesql In the SQL optimization process, you sometimes need to check which sqls have Multiple execution Plans (Multiple Executions Plans for the same SQL statement ), because the same SQL statement has multiple execution plans, it generally means that the

Obtain SQL Execution plans from the most authoritative Oracle Database This document is compiled and summarized based on relevant information. It mainly describes the most authoritative and correct methods and steps for obtaining SQL statement execution plans in Oracle databases. In addition, the meanings and usage of options in each method are also described in detail to help you check and use them in your

Ubuntu 16.04 System at the beginning of the installation is not able to switch to the root user, ordinary users need to use root permissions when you usually need to add "sudo" before executing the command, requires frequent use of root permissions of the partners may feel that this will make our egg classmate very sad ...In fact, to solve the problem of egg classmate is very simple, as long as the root with a password to switch to the root usersudo passwd RootAs followsFirst, enter the current

confirms that there are no problems with the configuration, select Done.After the creation is complete.====================================================================We can manually execute a maintenance plan to verify the configuration.If there are more than one sub-plan under the maintenance plan, we cannot do it manually in the same way, otherwise we will get an error.An error such as.We need to locate the SQL Server Agent under "Jobs" to perform maintenance planning tasks:Right-click t

which Python algorithm packages. (I have not done, the latter need to choose another direction to learn.) But it will probably be machine learning ~)Nonsense so much. It is also because I have always wanted to learn python, but have not found the right point of focus. But after writing this round of code, there is a general understanding of Python, although still very simple, but basically can meet the daily use of the date requirements. The heart is still flattered. Of course, these things are