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MySQL performance optimization of the sub-database table with no downtime to modify the MySQL table structure, the need for friends can refer to the next1, sub-database sub-tableObviously, a main table (that is, very important tables, such as user tables) unlimited growth is bound to seriously affect performance, sub-l

MySQL Sub-Library sub-table schemeWhy do you want to divide tablesWhen the data of a table reaches tens of millions of, the time you spend querying is much more, and if you have a joint query, I think I might die there. The purpose of the sub-table is to reduce the burden on the database and shorten the query time.One mechanism in MySQL is table locking and row l

In the introduction of For this problem, one can think of a brute-force solution: simply try to sum all possible combinations. An array of n exists in a n-1/2 combination, and then each combination is summed. That is, three for loop traversal, the number of each subarray in the array, and finally find out the maximum value of these sub-arrays. Sum[i,..., J] The sum of the elements of element A to the J element and (wherein 01 Packagealgorithms;2 3 /*

Tags: ICA span database Development SDN HREF Tar Article sub-tablebasic idea and segmentation strategy of database sharding on the grain size of vertical splitting vertical sharding Database Library Sub-table (sharding) series (i) Split implementation policy and sample demo Database Library Sub-table (sharding) series (ii) Global primary key generation strategy D

Vi cursor movement command 2, vi cursor command I. Overview W: Move a word forward with the same punctuation. B: Move a word backward. punctuation marks are the same as words. W: Move a word forward to ignore punctuation marks. B: Move a word backward to ignore punctuation marks. Ii. Example Initial status (Note: There is a space before tomato and Cot) Apple, banana, pear; tomato, patato; baby cot,

Vi shortcut key accumulation, vi shortcut key You may have forgotten what you have used, what you have not remembered, or when you have used it. 1. Select All and copy and paste them. Select All:GgVG// Note:Move gg cursor to first lineV enters Visual modeMove the G cursor to the last row and select all You can perform other operations, such:"+ Y copy the selected content to the + register, that is, th

Detailed description of vi commands and vi commands Esc switch mode Esc + I insert before the cursor Esc + a Insert after cursor Esc + o line feed Esc + u undo Esc + dl delete a character Esc + dd delete a row Esc + x delete a character Esc + yy copy a row at the cursor + p paste it to the next row of the cursor Esc + q do not save and exit Esc + wq! Force exit after saving Pwd current path S

Recently in this sharding-sphere, the company's internal sub-database sub-table is in this business code on the logical sub-database sub-table, but this is always bad, but also research several sub-database sub-table middleware, M

1050 Loop Array Maximum sub-segment and base time limit: 1 second space limit: 131072 KB Score: 10 Difficulty: 2-level algorithm topic collection concerns the cyclic sequence consisting of n integers a[1],a[2],a[3],..., a[n], the sequence as a[i]+a[i+1]+...+a[j] Continuous sub-segments and the maximum value (the loop sequence is the number of n is enclosed in a circle, so you need to consider a sequence suc

Use the swoole process Module to manage php processes. In the putty window, run the php Command to execute the main program. The main program creates a sub-process and outputs a number every two seconds, how can I see the output of a sub-process? Putty uses the swoole process Module to manage php processes. In the putty window, the php Command executes the main program. The main program creates a

Note: Sub-sequences, which can be discontinuous;The following topics, as I see it, are difficult to rank from easy to difficult:Max and sub-sequences (Maximum sum subsequence)This problem is purely entertaining ... There should be no such problem. The scenario is to put the sequence into a positive number.vectorint> msseq (vectorint> num) { vectorint> result; for (int i:num) if 0 )

Python Regular Expression replacement string function re. sub usage example, pythonre. sub This example describes how to use the Python Regular Expression replacement string function re. sub. We will share this with you for your reference. The details are as follows: Python re. sub is a standard library of python reg

Set class and sub-class:TreeSet ordered sub-class;HashSet unordered (hash) sub-classThe contents of the HashSet subclass are not sequential, and the individual elements are not duplicated (except for the object).set　　TreeSet Order:The TreeSet sub-class implements the Sortset subclass (sort) interface, TreeSet interface

1, sub-database sub-tableObviously, a main table (that is, very important tables, such as user tables) unlimited growth is bound to seriously affect performance, sub-library and sub-table is a very good solution, that is, the performance optimization approach, now the case is that we have a 1000多万条 record of the user t

Tags: strong upper solution Unit tracking System Dex HTTP Integration ServiceSharding is a direct way to address the limits of database storage capacity. Shards include both vertical and horizontal shards. Vertical shards Vertical fragmentation is also called vertical segmentation, that is, in logical tables, the original database is cut into multiple databases. After slicing, different tables are stored on different databases. Vertical sharding is closely linked to business architecture design

Request too much, a redis is not busy----->redis master-slave replication, Sentinel, Redis cluster cluster ... Redis itself has a small amount of data, and multiple redis have full data, no problem. What about the database?The amount of data in a table is too large to be a table. The amount of data in a database is too large for the library. How do you divide the data into each table, each library, and get it from there? There has to be a strategy or an algorithm (hash remainder).Further thinkin

Tags: MySQL sub-database sub-table backupOne, backup the database separatelyMysqldump-uroot-poldboy Oldboy >/opt/oldboy.sql The simplest backup1) MySQL based MyISAM engineMysqldump-uroot-poldboy-b-x-f Oldboy | Gzip >/opt/oldboy.sql.gz2) After 5.5 The default is InnoDB (recommended)Mysqldump-uroot-poldboy-b-F--single-transactio Oldboy | Gzip >/opt/oldboy.sql.gzsecond, multi-instance

1 What is the basic idea of a sub-database table?It is literally a simple way to store data that is stored in a single library on multiple libraries, storing data that was originally stored in a single table on multiple tables.2 Why should the basic idea be divided into sub-tables?The amount of data in the database is not necessarily controllable, in the case of no sub