Migrations will get run on app startup and are designed to modify :mnesia's schema.

table-copies

Table Copies

In the options of an ActiveMemory.Table, the copy type and nodes which should have them can be specified.

ram-copies

Ram copies

Tables that only reside in ram on the nodes specified. The default is node() Example table using default setting:

defmodule Test.Support.Dogs.Dog do
  use ActiveMemory.Table,
    options: [compressed: true, read_concurrency: true]
  .
  # module code
  .
end

The default will be [node()] and this table will reside on the node() ram. Example table spcifing nodes and ram copies:

defmodule Test.Support.Dogs.Dog do
  use ActiveMemory.Table,
    options: [compressed: true, read_concurrency: true, ram_copes: [node() | Node.list()]
  .
  # module code
  .
end

All the active nodes in Node.list() and node() will have ram copes of the table.

disc-copies

Disc copies

Disc copy tables reside both in ram and disc on the nodes specified. In order to persist to disc the schema must be setup on at lest one running node. The default is [] (no nodes). Example table spcifing nodes and disc copies:

defmodule Test.Support.Dogs.Dog do
  use ActiveMemory.Table,
    options: [compressed: true, read_concurrency: true, disc_copes: [node()]
  .
  # module code
  .
end

The table will have a ram copy and disc copy on node()

disc-only-copies

Disc only copies

Disc oly tables reside only on disc on the nodes specified. In order to persist to disc the schema must be setup on at lest one running node. The default is [] (no nodes). Example table spcifing nodes and disc copies:

defmodule Test.Support.Dogs.Dog do
  use ActiveMemory.Table,
    options: [compressed: true, read_concurrency: true, disc_only_copes: [node()]
  .
  # module code
  .
end

The table will only have a disc copy on node()

table-read-and-write-access

Table Read and Write Access

Mnesia tables can be set to read_only or read_write. The default is read_write. Read only tables updates cannot be performed. if you need to change the access use the following syntax: [access_mode: :read_only]

table-types

Table Types

Tables can be either a :set, :ordered_set, or a :bag. The default is :set if you need to change the type use the following syntax: [type: :bag]

indexes

Indexes

If Indexes are desired specify an atom attribute list for which Mnesia is to build and maintain an extra index table. The qlc query compiler may be able to optimize queries if there are indexes available. To specify Indexes use the following syntax: [index: [:age, :hair_color, :cylon?]]

table-load-order

Table Load Order

The load order priority is by default 0 (zero) but can be set to any integer. The tables with the highest load order priority are loaded first at startup. If you need to change the load order use the following syntax: [load_order: 2]

majority

Majority

If true, any (non-dirty) update to the table is aborted, unless a majority of the table replicas are available for the commit. When used on a fragmented table, all fragments are given the same the same majority setting. If you need to modify the majority use the following syntax: [majority: true]