sql query index

Database indexes are divided into clustered indexes and non-clustered indexes. Clustered indexes are physical indexes, that is, the physical storage order of data. The leaf node of clustered indexes is the data row itself; non-clustered indexes are

35. use SQL query analyzer and SQL profilerUse SQL query AnalyzerUse SQL profilerOptimize T-SQL statementSummaryIn this chapter, we will continue with the description of the pre-stored procedures in Chapter 21st. This chapter describes how to use

This article is transferred from: Http://www.cnblogs.com/abcdwxc/archive/2007/12/11/990274.html ----------------------- Creates an index for a given table or view.Only the owner of a table or view can create an index for the table. The owner of a

MySQL index details, MySQL index detailsI. Introduction to index basics 1.1 In MySQL, indexes are also called keys. They are a data structure that the storage engine uses to quickly find records. Indexes are critical to good performance. Especially

It is understood that most developers have a smattering of understanding of the index, limited to most of the daily work no opportunity, what is not necessary to care about, understand the index, it is really a query too slow to find the query

0. ReferencesTable Scan, Index Scan, index SeekSQL Server–index Seek vs. Index Scan–diffefence and Usage–a simple NoteHow Oracle tables are accessedDifference between index seek and index scan and where applicableHow to access tables in 1.oracleIn

It is understood that the vast majority of developers understand the index is smattering, limited to the majority of daily work without opportunities, and what is not necessary to care about the index, it is a query is too slow to find the query

The main considerations for designing SQL Server indexes are as follows:Check where condition and join condition column;Use narrow index;Check the selectivity of the column;Check the data type of the column;Consider the order of the columns;Consider

server| Difference | index | optimization In the principle of the database, the explanation of the clustered index is that the order of the clustered index is the physical storage order of the data, but the explanation of the nonclustered index is

The main considerations for designing SQL Server indexes are as follows:Check where condition and join condition column;Use narrow index;Check the selectivity of the column;Check the data type of the column;Consider the order of the columns;Consider