how to improve query performance

1. What is read/write splitting?   One of the most powerful functions of MySQL Proxy is to implement Read/Write Splitting )". The basic principle is to allow the primary database to process transactional queries, but to process SELECT queries from

Optimize the SQL related to the hotspot table. If the SQL Execution takes too long, it will hold latch for a long time. For statements with a small number of returned results, check whether indexes and partition conditions are used. Optimize the

Database usage-oracle bitmap Index Currently, a large number of indexes are mainly B * Tree indexes. The index structure stores the rowids of key values and key values, which correspond one to one. Bitmap indexes are mainly created for a large

Introduction: Oracle DatabaseIt is widely used in various fields of society, especially in the Client/Server mode. However, application developers often encounterSystem PerformanceAs the data volume increases significantly, to solve this problem,

Oracle DatabaseIt is widely used in various fields of society, especially in the Client/Server mode. However, application developers often encounter the problem that the performance of the entire system decreases significantly as the data volume

[Oracle] Local VS Global partition index in Oracle, the index and table can also be partitioned. There are two types of partition indexes: Local and Global ). 1. The Local index is created using the LOCAL keyword. The partition boundary is the same

Oracle Partition Summary This article describes the concepts and operations of Partition tables from the following aspects: 1. table space and Partition Table concept 2. table Partition Function 3. advantages and disadvantages of Table Partitioning 4

I remember that a few years ago, when ASP. NET emerged, a "giant" appeared in the Web development framework across the world. WebForms, a development framework that everyone seemed to be able to master, almost instantly became popular. If someone is

Oracle Database indexes are the structures on disks associated with tables or views. We can retrieve rows from tables or views more quickly. Oracle Database indexes mainly contain keys generated by one or more columns in a table or related view.

Open-source MySQL efficient data warehouse solution: Infobright details, mysqlinfobright Infobright is a column-based database based on unique patented knowledge grid technology. Infobright is an open-source MySQL Data Warehouse solution that

Today, we will mainly discuss the correct use of MQT materialized query tables in the DB2 materialized view, the following is a detailed description of the main content of the correct use of the MQT materialized query table in the materialized view

By separatingSQL statement for local range data scanning Generally, it is more effective to put all components of an SQL statement that implements a function together. However, in a few cases, the SQL separation method is more effective. This

The most important component of Oracle SQL running time is the time spent preparing new SQL statements for execution. However, if you understand the Inherent Mechanism of executable plan generation, you can control the time spent by Oracle in

Factors that affect database performance include: 1. Logical design of the database2. Actual database deployment3. server hardware Specification4. Use of indexes and SQL statements   Database Logic DesignTry to achieve the third paradigm (3nf)  

Preface: indexes have a crucial impact on the query speed. Understanding indexes is also the starting point for optimizing database performance. Consider the following: Assume that a table in the database has 10 ^ 6 records, the page size of the

Principles and methods for adjusting the performance of Oracle Application Systems Reprinted Source: China IT lab Author: Unknown Abstract:This article discusses and studies the features and

As we all know, indexes can improve query performance, but they cannot be used in disorder. Determine the gains and losses When indexes exist, the so-called "index fragmentation" is generated during insert, delete, and update operations. Index

A common table in Oracle is called a heap table. The data in the heap table is stored unordered and often becomes unordered after a period of time. As shown in, the data corresponding to the same key in the index is stored in different blocks. In

Index: an index is a collection of tables or views. It is used to accelerate the retrieval of rows from a table or to enforce uniqueness. Clustered index: an index created by physically ordered sorting. Non-clustered index: an index created

In general Server databases operate in a single thread when performing query jobs. SQL Server provides the parallel query function to cope with large-volume query tasks. The advantage of parallel query is that it can process query jobs through