10 course recommendations on indexing

Generally enable full text search when creating a table. The CREATE TABLE statement accepts the FULLTEXT clause, which gives a comma-separated list of indexed columns. The following CREATE statement demonstrates the use of the FULLTEXT clause: Input: create table productnotes ( note_id int NOT NULL AUTO_INCREMENT, prod_id char(10) &n

1. MySQL full text search: Enable full text search support

##Introduction: Full text search is generally enabled when creating a table. The CREATE TABLE statement accepts the FULLTEXT clause, which gives a comma-separated list of indexed columns. The following CREATE statement demonstrates the use of the FULLTEXT clause: Input:

2. MySQL avoids using OR conditions for index columns

#Introduction: I have suffered this loss many times. In the sql code before development, many queries with or as the where condition were even updated. Here are examples to illustrate the disadvantages of using or and how to improve it. selectf_crm_idfromd_db...

3. The problem of select count(*) query optimization and index creation when there is multiple data

Introduction: InnoDB table type, select count(*) where condition is followed by 12 query values, and it takes about 5 seconds to query 500,000 pieces of data without indexing. I would like to ask if building an index column is the best solution for this situation. , By the way, is the consumption of an index column and an index equal? ​​For example, the impact increases...

4. The problem children all come from the different world ova php interview encountered Record the questions here

Introduction: Problem children all come from another world ova: Problem children all come from another world ova php Questions encountered in the interview are recorded here ：Code optimization The copy code is as follows: for($i=0;$i<8;$i++){ array_push($week,$arr); } The copy code is as follows: for($i=0;$i<8 ;$i++){ $week[]=$arr[$i]; } //In this way, there is no additional burden of calling functions. The advantages and disadvantages of creating an index: When querying, you will first go to the index list to locate a specific The number of rows of values ​​greatly reduces the number of matching rows traversed Disadvantages: This table must be queried no matter what,

5. Mysql related_MySQL

Introduction: It is similar to the previous ordinary index, except that the value of the index column must be unique, but null values ​​are allowed. In the case of a composite index, the combination of column values ​​must be unique. It has the following creation methods

6. Some optimization methods and precautions for using indexes in mysql

Introduction : This article collects a lot of information from the Internet about how to use indexes in MySQL to optimize your own database. It also introduces some situations where index columns cannot appear, etc.

7. High-performance MySQL (5) Create a high-performance index-hash index

Introduction: Hash index (hashindex) is implemented based on hash table. Only queries that exactly match all columns of the index are valid. For each row of data, the storage engine will search all indexes. The column calculates a hash code, and the rows with different key values ​​​​calculate

8. What are the reasons why Oracle does not use indexes?

#Introduction: Today I will summarize the reasons why Oracle does not use indexes. Take notes as you study. The clustering factor is a measure of the similarity between the data order of the index columns and the data order of the table fields.

9. A brief summary of Oracle index

Introduction: Sort first when creating an index, which is logically divided into Root (root block) and Branch (stem pieces), leaf (leaf pieces). The value, length, and rowid of the index column exist in leaf, and the stem block stores

10. The order of output results of MySQL select * when there is an index column

Introduction: Create a table with a primary key column and an index column. Then insert a batch of data and call select * from test_b. You can find that the output results are not ordered according to Id,

[Related Q&A recommendations]:

Mysql Is there any command that allows mysql to use two indexes at the same time

MySQL partition index

mysql INNODB update statement lock sequence

php - Issues with select count(*) query optimization and index building when there is multiple data

Index - Mysql Limit query optimization issues

The above is the detailed content of 10 course recommendations on indexing. For more information, please follow other related articles on the PHP Chinese website!