PostgreSQL , ms sql , SQL Server
This paper introduces the simple deployment and use of MS SQL on Linux.
Later, I will briefly introduce how to migrate MS SQL to PostgreSQL.
CentOS 7.x x64 ECS
2. Environmental ...
Posted by MikeA on Sun, 12 May 2019 02:10:42 +0200
PostgreSQL, citus, pgbouncer, network optimization, worker node
Network requirements between citus nodes:
1. The cn node accesses all worker nodes. oltp services are frequently accessed.
2. When data is redistributed, worker nodes visit each other. Access frequency is not high, OLAP business is common, once possible, data ex ...
Posted by nic0las on Sun, 12 May 2019 01:30:39 +0200
The following personal learning notes are for reference only. You are welcome to make corrections.
MyBatis is a persistent layer framework that supports customized SQL, stored procedures, and advanced mapping. It mainly accomplishes two things:
Encapsulating JDBC operations
Using Reflection to Interchange Java Classes and SQL Statemen ...
Posted by ScratchyAnt on Sat, 11 May 2019 16:37:13 +0200
Return Proxy SQL Series: http://www.cnblogs.com/f-ck-need-u/p/7586194.html
1. Understanding Chain Rules
In the mysql_query_rules table, there are two special fields, "flagIN" and "flagOUT", which are used to define the entry and exit of the rules respectively, so as to realize the chains of rules.
The implementation of ch ...
Posted by pob123 on Sat, 11 May 2019 15:33:54 +0200
ContentProvider is mainly used to realize data sharing between different applications. It provides a complete mechanism to allow one program to access data in another program, while ensuring the security of the visited data.
PS: The bottom layer of ContentProvider is to adopt the Binder mechanism in Android
The main methods ...
Posted by Masterchief07 on Sat, 11 May 2019 14:25:38 +0200
The cursor is used to process the query result (ResultSet) of the select statement.
Some people also think that cursors are query results
Use steps and grammatical formats (non-scrolling cursors)
1. Declare cursors
Cursor cursor name is select statement ...
Posted by Melville on Sat, 11 May 2019 10:26:11 +0200
Snap-up and second-kill are common scenarios. Interviewers often ask questions during interviews, such as how to achieve the snap-up second-kill in Taobao.
Buying and killing in seconds is very simple, but there are some problems to be solved, mainly for two problems:1. Pressure on databases caused by high concurrency2. How to ...
Posted by philooo on Fri, 10 May 2019 20:28:18 +0200
Through dynamic SQL, we can compile complex SQL, but the previous examples are single-table queries. In actual development, of course, not all single-table queries. Many times we need to carry out related multi-table queries (some companies still try to use single-table queries for performance). The relationship between tables ...
Posted by oaskedal on Fri, 10 May 2019 14:16:08 +0200
# JDBC Introduction Foundation, Use Steps
Recently, in reviewing the knowledge of JDBC, first write a review of the basis of JDBC.
For the understanding of JDBC, the full name of JDBC is Java Database Connectvity, so it is not difficult to write out, that is, using the java language to operate the database. JDBC actually defines ...
Posted by dbdbdb on Fri, 10 May 2019 00:48:03 +0200
Data Lake Analytic DLA (hereinafter referred to as DLA) can help users directly query and analyze data stored on OSS and TableStore through standard SQL statements.
For the same data, it is not only different in storage space, but also different in execution time when using DLA query. Generally speaking, when data of the same size is st ...
Posted by growler123 on Thu, 09 May 2019 17:50:03 +0200