Where are tables in Mnesia located?

Posted by Sanoj on Stack Overflow See other posts from Stack Overflow or by Sanoj
Published on 2010-04-07T22:21:25Z Indexed on 2010/04/07 22:23 UTC
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erlang

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mnesia

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limitations

I try to compare Mnesia with more traditional databases.

As I understand it tables in Mnesia can be located to:

ram_copies - tables are stored in RAM only, so no durability as in ACID.
disc_copies - tables are located on disc and a copy is located in RAM, so the table can not be bigger than the available memory?
disc_only_copies - tables are located to disc only, so no caching in memory and worse performance? And the size of the table are limited to the size of dets or the table has to be fragmented.

So if I want the performance of doing reads from RAM and the durability of writes to disc, then the size of the tables are very limited compared to a traditional RDBMS like MySQL or PostgreSQL.

I know that Mnesia aren't meant to replace traditional RDBMS:s, but can it be used as a big RDBMS or do I have to look for another database?

The server I will use is a VPS with limited amount of memory, around 512MB, but I want good database performance.

Are disc_copies and the other types of tables in Mnesia so limited as I have understood?

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