at t renew plan

restriction condition of the application query. Therefore, if a large table has a restriction condition in the WHERE condition (such as the equivalence restriction ), this large table is also suitable as the driving table, so not only a small table can be used as the driving table. The correct statement should be based on the restrictions of the application query, returns the table with fewer row sources as the driving table. In the Execution Plan, i

Brief introduction: This article introduces comprehensively in detail OracleImplement the relevant concepts of the plan, access methods of accessing data, connections between tables, and so on. and a summary and overview, easy to understand and memory! +++ Directory---one. Concepts related to the concept of rowid recursive SQLConcept predicate (predicate) driving table (Driver table) probed table (probed table) combined index (concatenated Index) Opti

Label:This document is based on the relevant data collated, summarized, mainly on the Oracle database, to obtain the most authoritative and correct method of SQL statement execution plan, and also explained in detail the meaning of the options available in each method and how to use, so as to facilitate everyone and their daily work to consult the use of Because I did not find this blog support attachment upload function, need to PDF file format frien

It is often said that the business plan (Business) is the "stepping stone" for start-up financing. As a large number of start-up enterprises to finance the growth of the necessary documents, its role as a pre-listed company's prospectus, is a financing company or project to make a statement and analysis, to facilitate the potential investors to conduct a comprehensive understanding of the investment object and preliminary examination of the text file.

Label: Overview Adaptive Connection Method Ajm AJM Example Process flow of AJM Adaptive parallel allocation Method APDM APDM Example Process flow of APDM About allocation methods Summarize Reference OverviewWe know that before the 12c version, although the ACS, CFB and other functions by collecting information during the SQL text execution, to improve the execution

To obtain the execution plan in the cache library, you can directly query the dynamic performance view v $ SQL _plan and v $ SQL _plan_statistics_all, but the more convenient method is SQL _id and sub- To obtain the execution plan in the cache library, you can directly query the dynamic performance view v $ SQL _plan and v $ SQL _plan_statistics_all, but the more convenient method is SQL _id and sub- 1

Label:How to read Oracle's execution planFirst, what is the implementation planAn explain plan is a representation of the access path, that's taken when a query is executed within Oracle.Second, how to access dataAt the physical level Oracle reads blocks of data. The smallest amount Ofdata read is a single Oracle block, the largest are constrained by OperatingSystem limits (and Multib Lock I/O). Logically Oracle finds the data to read byusing the foll

In the previous article to introduce you to SQL Server execution plan cache (above), this article continues to introduce SQL Server implementation plan cache related knowledge, small partners to study together. Brief introduction In the previous article we talked about the relationship between the query optimizer and the execution plan cache, and the conflict b

Dbms_xplan is a package that Oracle provides to view SQL plans, including execution plans and interpretation plans, and I used the set autotrace command when I looked at the SQL execution plan, but now it seems that Dbms_ The Xplan package gives a simpler way to get and display a plan. These 5 functions correspond to different display plans, and the Dbms_xplan package can not only get an interpretation

Label:Explain the difference between a plan and an execution planWith the development tools that explain the output of the plan, such as the widespread use of toad, generating an interpretation plan becomes quite simple. Rather than simply getting the execution plan.Explain the planEXPLAIN plan is used to display the e

Label:The parameter sniff problem is to reuse the execution plan generated by other parameters, leading to the non-optimization of the execution plan by the current parameters. Presumably familiar with the data of the students should know that the most typical problem of producing parameter sniff is the use of parameterized SQL (or stored procedures using parameterized), if there is uneven distribution of d

Project Development Plan (GB856T--88) 1 Introduction 1.1 writing a project development plan is the first preliminary plan to be made when developing a project, you need to have a rough understanding of the conditions required for the entire project development process. The intended readers of the Project Development Plan