improve linq query performance

First: Write query statements that limit the search scope. As we all know, it is directly related to the efficiency of the query when the database query returns the number of records. Therefore, in the client through a certain conditional statement, limit the scope of the search, often can greatly improve the efficien

(Itemid in Integer,partid in integers, quan in integer) As BEGIN INSERT into item (id,orderid,stockid,quantity) VALUES (Itemid,orderseq. Currval,partid,quan); UPDATE Stock SET Onhand=onhand-quan WHERE Id=partid; End Placeitem; The application simply calls these procedures. PlaceOrder (3); Placeitem (1,3,2); Placeitem (2,8,1); Placeitem (3,9,3); When an application invokes a stored procedure, the data sent over the network is only a procedure call and a parameter. In this paper, the method t

file system represents one or more parameters, which can be read by the CAT tool or Modify the echo command. Listing 3 shows how to query or enable an adjustable parameter (in this case, IP Forwarding can be enabled on the TCP/IP stack ). [Root @ Camus] # CAT/proc/sys/NET/IPv4/ip_forward 0 [root @ Camus] # echo "1" >/Poc/sys/NET/IPv4/ip_forward [root @ Camus] # CAT/proc/sys/NET/IPv4/ip_forward 1 [root @ Camus] # Listing 3. Optimi

differences between different implementations when writing programs , this performance difference is particularly noticeable when the volume of data is particularly large or in large or complex database environments, such as online transaction processing OLTP or DSS for decision support systems. In practice, poor SQL often comes from inappropriate index design, non-sufficient connection conditions, and a WHERE clause that is not optimized. After the

that the cached data does not have to be on the same machine as the application, which greatly enhances the reusability of the cached data. The article describes how to do this in. NET application using Memcache as the distributed cache.memcached IntroductionMemcached is a software developed by Brad Fitzpatric, a Danga Interactive company in LiveJournal. In the common application we will save the data to the database, every time we need to query the

calls.For example, you can create a function to perform the following tasks: Establish a database connection, execute select statements for the database, obtain the search results, and finally return results in an array. Then, you can cache the result array returned by the function through the call method of the Cache_Lite_Function instance, so that you can read these arrays from the local cache rather than from the back-end database, which can significantly

, xmldata );FS. colse ();The generated binary file is called xmlbinary. If you open it directly with winhex, you can also see some XML tags in it. If the data volume is large, add a line of code:Xmldata. remortingformat = serializationformat. Binary;The generated file is called a truebinary file. when processing a large number (more than 10000 rows), the size of the generated file is one of the parts of xmlbinary. The storage mode is automatically saved during serialization, so the process of so

I was going to summarize this code performance article after I wrote the maintainability code article, delayed a few days, was also decided to update an article every day, because the previous owed too many things did not summarize, learned things did not go to sum up really quickly forget, record in your brain left a deeper impression, In particular, these maintainability codes, performance, and so on, whe

interface, do not pay attention to the efficiency of query statements, resulting in the development of the application system inefficient, resource waste is serious. Therefore, how to design efficient and reasonable query statement is very important. Based on the application example and database theory, this paper introduces the application of query optimization

Introduction to how to improve PHP performance by caching database results. However, when the database you are using is located on a different computer from the Web server, it is always a good way to cache the database result set. However, the best cache policy is determined based on your situation. However, when the database you are using is located on a different computer from the Web server, it is always

that 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 as a distributed cache in. NET applications.Introduction to MemcachedMemcached is a software developed by Brad Fitzpatric, Danga Interactive under LiveJournal. In common applications, we store the data in the database, and query the data from the database whenever needed

\ RDBMS \ ADMIN \ utlxplan. SQL to create the PLAN_TABLE table) SQL>SETAUTOTRACEON SQL>SETTIMINGON You can use set autotrace on to view the statement execution plan and set timing on to view the statement running time. SQL>selectcount(*)fromCASE_GA_AJZLZ; COUNT(*) 346639 Used time: 00: 00: 21.38 ExecutionPlan 0SELECTSTATEMENTOptimizer=CHOOSE 10SORT(AGGREGATE) 21TABLEACCESS(FULL)OF'CASE_GA_AJZLZ' …………………… Note that table access (FULL) in the preceding ana

Label:Traditional SQL PagingTraditional SQL paging, all the solutions are almost row_number, for the needs of a variety of sorting, complex query scenarios, Row_number is the killer. In addition, for the current web is very popular Poll/push load paging way, generally use time stamp to achieve paging. These two kinds of paging can be said that the former is universal, even LINQ generated by the paging is ro

Among the many features provided by ASP. NET, cache support is undoubtedly my favorite feature. I have a good reason to say so. Compared with all other ASP. NET featuresProgramThe performance has the greatest potential impact, using caching and other mechanisms, Asp. NET developers can accept the additional overhead when building a site using a control with a large overhead (for example, DataGrid), without worrying that the

The following article mainly introduces several practical operation solutions for improving MySQL database performance, including selecting the most suitable field attribute and correctly using JOIN) subquery (Sub-Queries. 1. select the most suitable field attribute MySQL can support access to large data volumes, but generally, the smaller the table in the database, the faster the query will be executed on

parallel computing ( line 7,8), because the results of the various sub-Libraries may have duplicate data also need to be summarized again, which requires the report engine has strong bulk data recalculation ability. 2. call the above set-up script in the collection report, and edit the report expression to complete the report production. Parallel multi-Library is applicable to the source data volume is large, and the amount of data is not removed, the data will be stored after the report stat

worry about the impact of performance. To maximize caching in your applications, you should consider ways to implement caching at all program levels. Steve's Caching Tips Cache as early as possible; You should implement caching at every level of your application. Add caching support to the data tier, business logic tier, UI, or output layer. Memory is now very cheap-therefore, a great performance improveme

　　first, the question of the proposed In the early stage of the application system development, because the development database data is few, to query the SQL statement, the complex view compilation and so on cannot realize the SQL statement various writing performance good or bad, but if the application system submits the actual application, as the data in the database increases, The response speed of the

How to improve performance in data processing-introduce concurrency but avoid synchronization background As long as there is a database, there will be a need to process data in batches in the background, such as data table backup, regular cleaning, data replacement, and data migration. for batch processing, it often involves a large number of queries, filters, classifications, and aggregate computing. in ba

/EF_Trick4.html 5. Delete and modify objects in batches. Do not query objects first, and then delete and modify objects one by one. This will produce a large number of statements, and the efficiency will certainly be low. The solution is to execute SQL statements directly, and write an extension method on your own. although many people disagree with this method. but I personally prefer to write an extension method myself. in this way, there are tw