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Questions tagged [mnesia]

A distributed DataBase Management System used in Erlang applications.

Mnesia is a distributed DataBase Management System (DBMS), appropriate for telecommunications applications and other Erlang applications which require continuous operation and exhibit soft real-time properties.

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mnesia:wait_for_tables/2 , do i really understand it?

I have used mnesia for a while now. I have to confess that i feel like i do not exactly understand the concept of mnesia:wait_for_tables/2. Quoting the documentation here below says this: Some applications need to wait for certain tables to be…
Muzaaya Joshua
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Erlang and JavaScript MD5 Digest match

Testing the Javascript Implementation of MD5 here: http://www.webtoolkit.info/javascript-md5.html gives the following output: MD5("muzaaya") = "00e081abefbbbf72b2d5258196a9b6d0" Going to my erlang shell, and calculating the MD5 of the same value i…
Muzaaya Joshua
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Where can I find Mnesia source code?

I've seen in a lot of documents that Mnesia has been open sourced by Ericsson, but straightforward googling didn't help me to find the repository with the code... Is Mnesia still open-source at all?
Vasil Remeniuk
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Mnesia Clustering

If I am clustering 2 nodes together, from my experimenting and reading up online I understand that Node A will be like a "master" node and Node B will copy the tables over if I want them to. (Otherwise it will just access them remotely.) What…
ewindsor
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How to ensure fast startup times of mnesia

Erlang with mnesia/dets is famous for it slow startup times after a crash. Basically the same issue as with fsck on older filesystems. But I also experience slow startup times after regular shutdowns: about 8 Minutes for 250 MB on-disk data on a…
max
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erlang mnesia - illegal record info

I am trying to have a function that ensures the table I need is already created and if not to create it. Here's the sample: ensure_table_exists(Table, MnesiaTables, Nodes) -> case lists:member(Table, MnesiaTables) of true -> …
hyperboreean
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How to read all the records of mnesia database in erlang?

I ma new in erlang and I need to do some operations for all records I get from mnesia database. Result = mnesia:dirty_read(mydatabase, {key1, key2}), case Result of [] -> ?DEBUG("No such record found", []); …
Besat
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Erlang: create a disc schema

If an Erlang application, myapp, requires mnesia to run, then mnesia should be included in its application resource file, under key applications, so that if myapp is started, mnesia would get started automatically - it's node type by default is…
Not an ID
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Stopping of Erlang app hangs when mnesia stopped from within the program

I've run into a problem where I cannot stop mnesia within my program without causing the app to hang. I'm presently doing prototyping of mnesia within my erlang app. In my jaus_app.erl file the start() calls: {atomic, ok} =…
Ken Robinson
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How to check Mnesia database of ejabberd

I want to access Mnesia database of ejabberd server, But i don't know how to read,write and update the data, Is there a way by which i can do this. Can i change Database to MySQL rather than Mnesia. I have tried this {odbc_server, {mysql,…
Hemant Sharma
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Erlang: Mnesia or Mysql?

What DBMS do you use with Erlang ? and Why ?
xRobot
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What is Mnesia replication strategy?

What strategy does Mnesia use to define which nodes will store replicas of particular table? Can I force Mnesia to use specific number of replicas for each table? Can this number be changed dynamically? Are there any sources (besides the source…
citxx
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What is the difference between "raw" dirty operations, and dirty operations within mnesia:async_transaction

What is the difference between a series of mnesia:dirty_ commands executed within a function passed to mnesia:async_dirty() and those very same transactions executed "raw"? I.e., is there any difference between doing: mnesia:dirty_write({table,…
Jr0
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Better understanding how to work/balance mnesia's transactional/ACID capabilities

I am still trying to deeply understand what one can do with Mnesia, and answers to these two questions would greatly help. 1) What happens if one process does an atomic transaction with respect to Record X while some other process does a dirty…
Jr0
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Web server tolerance to high client poll rate: Cowboy vs. Yaws web servers

I have been building a real-time notification system. It’s part of a web application, but events have to be seen as soon as they occur. Long polling was not an option because it would be expensive for the web server to hold on to connections when no…
Muzaaya Joshua
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