Comments on: Mnesia Records to MongoDB Documents http://streamhacker.com/2010/02/01/mnesia-records-mongodb-documents/#utm_source=feed&utm_medium=feed&utm_campaign=feed Weotta be Hacking Thu, 19 Apr 2012 12:53:00 +0000 hourly 1 http://wordpress.org/?v=3.3.1 By: Jacob Perkins http://streamhacker.com/2010/02/01/mnesia-records-mongodb-documents/comment-page-1/#comment-948 Jacob Perkins Tue, 27 Mar 2012 22:34:00 +0000 http://streamhacker.com/?p=916#comment-948 The idea with plists is to be a drop-in replacement for functions in lists, with the option of customizing the parallelization by specifying a Malt. ptable then expands on that, but instead of providing a list, you give a mnesia table name and match specification. So for the ptable:foreach functions, F is the function to call on each record in mnesia, Table and Spec are passed thru to mnesia:select in order to select the objects, and Malt is passed to plists:foreach along with F and a list of objects from mnesia. I don't have an example handy since I haven't used this code in years, so I recommend reading up on plists & Malt, and mnesia match specifications. The idea with plists is to be a drop-in replacement for functions in lists, with the option of customizing the parallelization by specifying a Malt. ptable then expands on that, but instead of providing a list, you give a mnesia table name and match specification. So for the ptable:foreach functions, F is the function to call on each record in mnesia, Table and Spec are passed thru to mnesia:select in order to select the objects, and Malt is passed to plists:foreach along with F and a list of objects from mnesia. I don’t have an example handy since I haven’t used this code in years, so I recommend reading up on plists & Malt, and mnesia match specifications.

]]> By: DG http://streamhacker.com/2010/02/01/mnesia-records-mongodb-documents/comment-page-1/#comment-947 DG Tue, 27 Mar 2012 20:17:00 +0000 http://streamhacker.com/?p=916#comment-947 Hi Jacob, I'm a newbie to erlang (but quite solid in C and DBMS like sqlite, postgres, db2) and trying to use mnesia for a project at university. I found really interesting your comments here and more interesting your elib code... the problem is I'm not able to figure out how to use it :(  My intentions would be to have parallel processes (read, math functions, write) on data from one or more tables (possibly partitioning on several nodes). I've seen you implemented ptable in elib using plist (by you and Stephen Marsh)... I searched a while for someone using it but seems difficult, surely i'm missing something... Could you post an (even extremely) simple example of the combination ptable-mnesia? Hi Jacob,
I’m a newbie to erlang (but quite solid in C and DBMS like sqlite, postgres, db2) and trying to use mnesia for a project at university. I found really interesting your comments here and more interesting your elib code… the problem is I’m not able to figure out how to use it :(  
My intentions would be to have parallel processes (read, math functions, write) on data from one or more tables (possibly partitioning on several nodes). I’ve seen you implemented ptable in elib using plist (by you and Stephen Marsh)…

I searched a while for someone using it but seems difficult, surely i’m missing something…
Could you post an (even extremely) simple example of the combination ptable-mnesia?

]]> By: Jacob Perkins http://streamhacker.com/2010/02/01/mnesia-records-mongodb-documents/comment-page-1/#comment-824 Jacob Perkins Sun, 03 Apr 2011 23:11:00 +0000 http://streamhacker.com/?p=916#comment-824 I don't have the code anymore, but if you're interested in using erlang with MongoDB, checkout emongo: https://github.com/JacobVorreuter/emongo. Or for some mnesia helper code, there's my etable module in elib: https://github.com/japerk/elib/blob/master/src/etable.erl. The transfer from mnesia to mongo was really just pattern matching & record conversion using both of those. I don’t have the code anymore, but if you’re interested in using erlang with MongoDB, checkout emongo: https://github.com/JacobVorreuter/emongo. Or for some mnesia helper code, there’s my etable module in elib: https://github.com/japerk/elib/blob/master/src/etable.erl. The transfer from mnesia to mongo was really just pattern matching & record conversion using both of those.

]]> By: JLM http://streamhacker.com/2010/02/01/mnesia-records-mongodb-documents/comment-page-1/#comment-823 JLM Sun, 03 Apr 2011 22:47:00 +0000 http://streamhacker.com/?p=916#comment-823 Hi I'm really new to Erlang and I find it a really exciting languge and platform. Though it is a little bit rough and sometimes low-level for newbies. I understand almost all terms you used in this post but finally without viewing code, it stays too theorical. Would you mind sharing your code for newbies like me ? :-) Sorry if my comment comes a little bit late. Hi
I’m really new to Erlang and I find it a really exciting languge and platform. Though it is a little bit rough and sometimes low-level for newbies.
I understand almost all terms you used in this post but finally without viewing code, it stays too theorical. Would you mind sharing your code for newbies like me ? :-)
Sorry if my comment comes a little bit late.

]]> By: Jacob Perkins http://streamhacker.com/2010/02/01/mnesia-records-mongodb-documents/comment-page-1/#comment-731 Jacob Perkins Fri, 19 Nov 2010 14:58:00 +0000 http://streamhacker.com/?p=916#comment-731 I'm not sure how much good it was doing anyway, so I removed it. I’m not sure how much good it was doing anyway, so I removed it.

]]> By: Tkor http://streamhacker.com/2010/02/01/mnesia-records-mongodb-documents/comment-page-1/#comment-730 Tkor Fri, 19 Nov 2010 14:52:00 +0000 http://streamhacker.com/?p=916#comment-730 uh, turns out it's only a problem when you zoom it in, like I have to, because I am half blind. so, nevermind. uh, turns out it’s only a problem when you zoom it in, like I have to, because I am half blind. so, nevermind.

]]> By: Tkor http://streamhacker.com/2010/02/01/mnesia-records-mongodb-documents/comment-page-1/#comment-729 Tkor Fri, 19 Nov 2010 14:50:00 +0000 http://streamhacker.com/?p=916#comment-729 The big "FOLLOW ME" frame to the left leaves your blog all but unusable. Really, you'd be better off removing it completely. The big “FOLLOW ME” frame to the left leaves your blog all but unusable. Really, you’d be better off removing it completely.

]]> By: Tweets that mention Migrating Mnesia Records to MongoDB Documents using Erlang emongo driver « streamhacker.com -- Topsy.com http://streamhacker.com/2010/02/01/mnesia-records-mongodb-documents/comment-page-1/#comment-387 Tweets that mention Migrating Mnesia Records to MongoDB Documents using Erlang emongo driver « streamhacker.com -- Topsy.com Sat, 06 Feb 2010 12:24:37 +0000 http://streamhacker.com/?p=916#comment-387 [...] This post was mentioned on Twitter by Jacob, NoSQL Update. NoSQL Update said: #NoSQL Stats heavy post RT @japerk: streamhacker.com: Mnesia Records to MongoDB Documents http://bit.ly/d3rKvF #erlang #mongodb [...] [...] This post was mentioned on Twitter by Jacob, NoSQL Update. NoSQL Update said: #NoSQL Stats heavy post RT @japerk: streamhacker.com: Mnesia Records to MongoDB Documents http://bit.ly/d3rKvF #erlang #mongodb [...]

]]> By: Jacob http://streamhacker.com/2010/02/01/mnesia-records-mongodb-documents/comment-page-1/#comment-359 Jacob Tue, 02 Feb 2010 17:41:17 +0000 http://streamhacker.com/?p=916#comment-359 Thanks Casey, I've definitely been thinking about doing that. I think mnesia would be a great distributed in-memory cache. Thanks Casey, I’ve definitely been thinking about doing that. I think mnesia would be a great distributed in-memory cache.

]]> By: Jacob Perkins http://streamhacker.com/2010/02/01/mnesia-records-mongodb-documents/comment-page-1/#comment-701 Jacob Perkins Tue, 02 Feb 2010 17:41:00 +0000 http://streamhacker.com/?p=916#comment-701 Thanks Casey, I've definitely been thinking about doing that. I think mnesia would be a great distributed in-memory cache. Thanks Casey, I’ve definitely been thinking about doing that. I think mnesia would be a great distributed in-memory cache.

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