performance mysql

To some extent, MySQL has only b-tree indexes. He has no bitmap index. There is also a hash index, only in the memory storage engine.The B-tree index is similar to that in Oracle.MySQL restrictions on B-tree:Only the full value blend is done or

4.5 Speed The alter TABLE operationPrinciple:The performance of the ALTER TABLE operation for MySQL is a big problem for large tables.MySQL performs most of the modification of table structure operations by creating an empty table with the new

The cache is stored in an application table and applied by a hash value that includes the following factors, the query itself, the database currently being queried, the version of the client protocol, and other information that may affect the return

1 Query TypeThe query type contains:A full table scan, index scans, range scans, unique index lookups, and constants.Const type: Primary key query is generally constAll Type: Full table scan2 Why to split a join operationCaching can is more

One1.1). Indexes reduce the amount of data the server has to examine.2). Indexes Help the server avoid sorting and temporary tables.3). Indexes turn random I/O into sequential I/O.Lahdenmaki and Leach ' s book also introduces a Three-star system for

1.Good Schema design is pretty universal, but the course MySQL have special implementation details to consider. In a nutshell, it's a good idea to keep things as small and simple as can. MySQL likes simplicity, and so would the people who has to

I. Introduction to the CLUSTERED index1. What is a clustered index?InnoDB ' s clustered indexes actually store a b-tree index and the rows together in the same structure.2. Why can a table have only one clustered index?When a table had a clustered

Directory MySQL Master-slave replication Copy Filter Replication and Monitoring Read and write separation of master-slave replication Backup and Recovery Table partitioning First, MySQL master-slave

Select the optimized data typeMySQL supports a very high number of data types, and choosing the right data type is critical to gaining performance. No matter what type of data you store, here are a few simple principles that can help you make a

1th MySQL architecture and history 1.2 concurrency controlMySQL implements concurrency control at two levels: the server layer and the storage engine layer. Read lock and Write lock:When dealing with concurrent reads or writes, you can solve the

Chapter III: Analysis of server performance? This chapter will answer the following three questions:? How to confirm that the server is in the best performing state? Find out why a statement isn't performing fast enough? Diagnostics are described by

The debugging of the lock is divided into two parts, one is the debugging of the server level lock. The second is the debug of the lock at the storage engine levelDebugging for server-level locks:The types of server-level locks are table locks,

6 Query Performance Optimization6.1 Why queries become slowThis illustrates the query execution cycle, from the client to the server side, the server-side resolution, the optimizer generates execution plans, executes (can be subdivided, the general

Using count () in SQL seems like a natural thing to do:SELECT COUNT (*) from TABLE_NAME;Sometimes it is really thought that the difference between count (*) and individual count (column_name) is that the latter will be more efficient (take too much

The following articles mainly introduce the practical operation solutions for compiling high-quality and high-performance MySQL syntaxes. We all know that the practical application of MySQL syntaxes has become more and more extensive, therefore, it

The following articles mainly introduce the practical operation solutions for compiling high-quality and high-performance MySQL syntaxes. We all know that the practical application of MySQL syntaxes has become more and more extensive, therefore, it

In the third edition of High-performance MySQL, the evaluation of indexes is mentioned: Samsung Evaluation (Three-star system).In the original English version of "High Performance MySQL (3rd Edition)" The third edition is: The index earns one star

This article explains how to completely optimize MySQL database performance in eight aspects. 1. selecting the most suitable field attribute MySQL can support access to large data volumes. However, the smaller the table in the database, the faster

The following articles mainly introduce the five configuration parameters that closely affect MySQL Performance. I saw the five configuration parameters that closely affect MySQL performance on the relevant website a few days ago, I think it's good.

The optimization of MySQL database performance is the only way to develop MySQL database. the optimization of MySQL database performance is also a witness to the development of MySQL database. The following describes how to optimize MySQL database