Summary of Oracle Performance Tuning recommendationsPrinciple One: Note the connection order in the WHERE clause:Oracle uses a bottom-up sequential parsing where clause, according to which the connection between tables must be written before other
MS SQL Server Query optimization methodThere are many reasons for the slow speed of queries, which are common1, no indexes, or no indexes (this is the most common problem with query slowness, is the flaw in programming)2, I/o throughput is small,
See a very comprehensive SQL optimization article, in the development of the work often do not consider the performance of the lack of (at the beginning of the data volume is not seen the difference in speed). But the more you write, the more you
optimization Problems of databasefirst, the question of the proposedIn the early stage of application system development, due to less development database data, the query SQL statement, complex view of the writing of the performance of the SQL
See a very comprehensive SQL optimization article, in the development of the work often do not consider the performance of the lack of (at the beginning of the data volume is not seen the difference in speed). But the more you write, the more you
Read Catalogue
(1) Select the most efficient table name order (valid only in the rule-based optimizer)
(2) connection order in the WHERE clause
(3) Avoid using ' * ' in the SELECT clause
(4) Reduce the number of accesses to the database
(
First, the question of the proposedIn the early stage of application system development, because the database data is relatively small, for querying SQL statements, complex view of writing and so on is not aware of the performance of SQL statements,
Read Catalogue
(1) Select the most efficient table name order (valid only in the rule-based optimizer)
(2) connection order in the WHERE clause
(3) Avoid using ' * ' in the SELECT clause
(4) Reduce the number of accesses to the database
(
The performance of the system is not ideal, except in part because the application load does exceed the actual processing capacity of the server, more because the system has a large number of SQL statements need to be optimized. In order to achieve
Warm tip: This article is from the Internet, I only do a little processing, not detailed research, only as a later unprepared for the need, if you like to enjoy the turn away.First, the question of the proposedIn the early stage of application
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