improve linq query performance

" is a redundant field. However, to increase the "total value" of the redundant field, you can improve the speed of query statistics, this is the space to change the time of the practice. Reasonable redundancy can disperse the concurrent pressure of the table with large data, and can speed up the special query, the redundant fields can reduce the connection of da

) this.width=650; "src="/img/fz.gif "alt=" Copy Code "style=" Margin:0px;padding:0px;border:none; "/>CSS selector weightsHere the CSS ID class tag Selector weights, that is, their priority, the greater the weight, the higher the priorityid:100Class:10Tag:1With the basics of the above two, let's go through the details of how to optimize CSS to improve performance1, reduce CSS nesting, it is best not to set more than three layers, the general case of bl

view if the query optimizer determines that the view can be replaced with some or all of the query, and this is a low-cost query plan. The second scenario uses an indexed view instead of the underlying table and its normal index. At this point, you do not need to refer to the view in the query, and the

possible using the absolute path, because it avoids the PHP to include_path to find the file speed, parsing the operating system path requires less time. 9, if you want to know the script to start execution (that is, the server to receive client requests) at the moment, using $_server[' request_time ' is better than time (). 10. Functions do the same function instead of regular expressions. 11, the Str_replace function is faster than the Preg_replace function, but the efficiency of the STRTR

the cached data does not need to be on the same machine as the application, thus greatly enhancing the reusability of the cached data. This article describes how to use memcache for Distributed easing in. NET applications.Save.Introduction to memcachedMemcached is Brad fitzpatric, danga interactive under livejournal.A software first developed. In common applications, we store data in the database, and query the data from the database every time we ne

$ SQL = "select count (qid) from test_querys where istested = 1And qid Qid from $ left_cr where issubmit = 1 and qid $ SQL = "selectCount (A. qid) from test_querysA left join (select qid from $ left_cr where issubmit = 1 and rankval = 1 and qid 1. The first query takes 2.9 s, and the second query takes 0.2 s! Use in with caution and use left join instead! 2. MySQL does not support the minus Operator A

Yesterday's SQL Server query performance optimization-index creation principle (I) mainly introduced the principle. today are some of the main principles and checks the created indexes. Iii. indexing principles In general, building indexes depends on the data usage scenarios. In other words, which SQL statements are commonly used to access data? Are these statements missing indexes (or there may be too many

with exists in many cases:Select num from a where num in (select num from B)Replace with the following statement:Select num from a where exists (select 1 from b where num=a.num)14. Not all indexes are valid for queries, SQL is query-optimized based on data in the table, and when there is a large amount of data duplication in the index columns, SQL queries may not take advantage of the index, as there are fields in the table Sex,male, female almost ha

optimized SQL statements as much as possible to reduce execution time. For example, do not include subqueries in query statements, make full use of indexes, and so on.2. String Manipulation Performance optimizationUse the ToString method of a value typeWhen you connect strings, you often use the "+" sign to add numbers directly to a string. This method, while simple, can get the correct results, but becaus

local and distributed caches, and the local cache caches the data in the local server memory or in the file. Distributed cache can cache large amounts of data, extensibility, mainstream distributed cache system has memcached, redis,memcached performance stability, data cache in memory, fast, QPS up to about 8w. If you want to persist data, choose Redis, and the performance is no less than memcached.Working

1. database access performance optimization　 Database Connection and Shutdown To access database resources, you need to create a connection, open a connection, and close the connection. These processes need to exchange information with the database multiple times for authentication, which consumes server resources. ASP. NET provides a connection pool to improve the impact of enabling and disabling databases

reduced. The challenge is to find the bottleneck and determine the solution.It is more difficult to adjust performance issues in browsers than in Java applications. There are much less methods for developers to debug JavaScript in various browsers. In Mozilla Firefox, you can use Firebug to debug JavaScript, but still cannot adjust many performance problems, such as browser rendering time consumption. To s