box.space._space

box.space._space¶

_space is a system space. It contains all spaces hosted on the current Tarantool instance, both system ones and created by users.

Tuples in this space contain the following fields:

• id,
• owner (= id of user who owns the space),
• name, engine, field_count,
• flags (e.g. temporary),
• format (as made by a format clause).

These fields are established by box.schema.space.create().

The system space view for _space is _vspace.

Example #1:

The following function will display every simple field in all tuples of _space.

function example() local ta = {} local i, line for k, v in box.space._space:pairs() do i = 1 line = '' while i <= #v do if type(v[i]) ~= 'table' then line = line .. v[i] .. ' ' end i = i + 1 end table.insert(ta, line) end return ta end 

Here is what example() returns in a typical installation:

tarantool> example() --- - - '272 1 _schema memtx 0 '  - '280 1 _space memtx 0 '  - '281 1 _vspace sysview 0 '  - '288 1 _index memtx 0 '  - '296 1 _func memtx 0 '  - '304 1 _user memtx 0 '  - '305 1 _vuser sysview 0 '  - '312 1 _priv memtx 0 '  - '313 1 _vpriv sysview 0 '  - '320 1 _cluster memtx 0 '  - '512 1 tester memtx 0 '  - '513 1 origin vinyl 0 '  - '514 1 archive memtx 0 ' ... 

Example #2:

The following requests will create a space using box.schema.space.create() with a format clause, then retrieve the _space tuple for the new space. This illustrates the typical use of the format clause, it shows the recommended names and data types for the fields.

tarantool> box.schema.space.create('TM', {  >  id = 12345,  >  format = {  >  [1] = {["name"] = "field_1"},  >  [2] = {["type"] = "unsigned"}  >  }  > }) --- - index: []  on_replace: 'function: 0x41c67338'  temporary: false  id: 12345  engine: memtx  enabled: false  name: TM  field_count: 0 - created ... tarantool> box.space._space:select(12345) --- - - [12345, 1, 'TM', 'memtx', 0, {}, [{'name': 'field_1'}, {'type': 'unsigned'}]] ...