mnesia db

; Uncertain transactions ---> Active tables User: with 0 records occupying 304 words of MEMSchema: with 2 records occupying 524 words of MEM==> System info in version "4.4.10", debug level = none Opt_disc. directory "/home/hwh/a" is used.Use fallback at restart = falseRunning dB nodes = [A @ localhost]Stopped dB nodes = []Master node tables = []Remote = []Ram_copies = []Disc_copies = [schema, user]Disc_only

Original article: http://www.erlang.se/publications/mnesia_overview.pdfAbstract: The mnesia DBMS and the application system with data run in the same address space. However, the application system cannot destroy the database content. Mnesia also provides fast access features and good fault tolerance. These two requirements are usually conflicting. Mnesia is imple

[Erl_question11] mnesia distributed application exampleScenario: Design a library management system. Requirements: 1. Basic addition, deletion, query, and modification functions; 2. multi-node backup is supported (one of the nodes fails and the external interface is not affected ).Solution 1: Erlang code: https://gist.github.com/zhongwencool/28f7db8d52134b082f97 Start shell: erl -name [emailprotected]127.0.0.1 -pa "../ebin/" -setcookie best -run c

The operations of the Mnesia database are almost different from those of the previously used SQL database. They are not used at the beginning. Below are some common read/write operations: 1. Example of dirty read mnesia: dirty_read (Tab, Key)-ValueList | exit ({aborted, Reason: for a set table, this operation returns one or more empty tables because of the set table key. The operations of the

Reprinted: http://www.cnblogs.com/gordonchao/archive/2010/12/13/1904606.html Symptom: Check the page and find that the data is abnormal. The data generated today is much lower than the normal level, which is not normal. Search for the cause: Check the log file and find a few such warnings: ** warning ** mnesia is overloaded: {dump_log, write_threshold} I found many foreigners encountered this problem during the query. Here I would like to say that fo

When creating mnesia, you must specify the table record structure. If the defined record structure is modified, you must update the table structure of the data. Otherwise, mnesia cannot read and write data normally. We initially defined the structure in this way. -Record (person, {name, age }). Then, create a table. Mnesia: create_table (person, [{disc_only_copie

Because the server is a version of servers, it is difficult to visually see Mnesia data. So it's very confusing for beginners.Specifically in the QQ group to consult others. Others say that as long as the pong through the line, you can use RPC to operate the remote Mnesia database. Beginners too understand this meaning. Then specifically search for a bit, and finally found someone else about the two Erl nod

Document directory Synchronous writes Mnesia application configuration How it works If you're using mnesia disc_copies tables and doing a lot of writes all at once, you're 've probably run into the following message =ERROR REPORT==== 10-Dec-2008::18:07:19 ===Mnesia(node@host): ** WARNING ** Mnesia is overloaded:

http://blog.csdn.net/erlib/article/details/40743687Scene:Design a book Management system, needs:1. Basic additions and deletions function;2. Support Multi-node backup (one of the nodes is hung up, external interface does not affect).Programme one:The Erlang code is as follows: HTTPS://GIST.GITHUB.COM/ZHONGWENCOOL/28F7DB8D52134B082F97To start the shell: [email protected] -pa ". /ebin/"-setcookie best-run cloud_server start_link [email protected][email protected] [email protected] [email p

Entire SectionCodeTo use the mnesia database to implement sequence functions similar to those in Oracle. The original code is as follows: % Author: Administrator Usage: Id_generator: start_link (). Id_generator: getnewid (AAA ). Summary: 1. Be sure to write the parameter pair when creating the mnsia table 2. Define a table column as a record, and the second field has the same name as the table. 3. The table is not created successfully

Label:Mnesia is a distributed database management system, suitable for telecommunications and other applications requiring continuous operation and with the soft real-time characteristics of the Erlang, more and more attention and use, but the current Mnesia data is not much, many only the official user guide. The following will focus on how the Mnesia database implements SQL queries to implement SQL operat

What is ole db? Introduction to ole db, oledb Ole db (OLEDB) is a strategic low-level application interface for Microsoft to access different data sources. Ole db not only supports the Structured Query Language (SQL) of Open Database Connectivity (ODBC), but also supports other non-SQL data types.Introduction OLE stan

Encapsulate your own DB Class (PHP) and db Class php. Encapsulate your own DB Class (PHP). encapsulate db Class php to encapsulate a DB class for special database operations. any operations on the database in the future will be implemented by

Database operation functions in the CI framework $ this-> db-> where () usage summary, this-db- This example summarizes the usage of database operation functions $ this-> db-> where () in the CI framework. We will share this with you for your reference. The details are as follows: CI framework database operation function this->

Tags: png recover title cut ROS Development ext Cat TarThis article describes a simple SQL script that implements the ability to shrink all non-system db file sizes across Microsoft SQL Server instances. As a program that deals with SQL every day, apes often encounter db files that are too large to fill the space: For the development tester, if the DB data is n

Tags: process build rail info from BSP content lag stop For non-Oracle DB, SQL Server is a sample description: My train of thought A:oracle DB production B:oracle DB Intermediate machine C:sqlserver db destination a-> b->c Note: B on both the rep process also has the EXT process, at this time. There is also a need to e

Tags: Oracle goldengate initial Load methodNon-Oracle DB is illustrated with SQL Server as an example:My train of thoughtA:oracle DB production B:oracle DB Intermediate machine C:sqlserver db destinationa-> b->c Note: B on both the rep process and ext process, at this time, C also need to establish a rep process for B.

Document directory MVCC Horizontal scalability Query expression Atomicity Durability Map reduce Javascript Rest Performance Use Cases Http://www.mongodb.org/display/DOCS/Comparing+Mongo+DB+and+Couch+DB, English Http://www.searchdatabase.com.cn/showcontent_46595.htm (Chinese) The most fundamental difference is that the difference in application scenarios is the difference in the choice of CAP.

You cannot use Db-library (such as ISQL) or ODBC 3.7 or earlier to ntext data Warning:mssql_query () [Function.mssql-query]: message: You cannot ntext data or use Unicode collations with db-library (such as ISQL) or ODBC 3.7 or earlier The Unicode data is sent to the client. (severity) in D:phpnowhtdocss includedb_mssql.class.php on line 55 The code is as follows Copy Code Warn