Execution example::

  object_list
  # [
  #   [
  #     0, 
  #     1337566253.89858, 
  #     0.000355720520019531
  #   ], 
  #   {
  #     "UInt64": {
  #       "opened": true, 
  #       "flags": {
  #         "names": "KEY_UINT", 
  #         "value": 0
  #       }, 
  #       "n_elements": 4, 
  #       "path": null, 
  #       "size": 8, 
  #       "type": {
  #         "id": 32, 
  #         "name": "type"
  #       }, 
  #       "id": 11, 
  #       "name": "UInt64"
  #     }, 
  #     "Int32": {
  #       "opened": true, 
  #       "flags": {
  #         "names": "KEY_INT", 
  #         "value": 8
  #       }, 
  #       "n_elements": 4, 
  #       "path": null, 
  #       "size": 4, 
  #       "type": {
  #         "id": 32, 
  #         "name": "type"
  #       }, 
  #       "id": 8, 
  #       "name": "Int32"
  #     }, 
  #     "Int16": {
  #       "opened": true, 
  #       "flags": {
  #         "names": "KEY_INT", 
  #         "value": 8
  #       }, 
  #       "n_elements": 4, 
  #       "path": null, 
  #       "size": 2, 
  #       "type": {
  #         "id": 32, 
  #         "name": "type"
  #       }, 
  #       "id": 6, 
  #       "name": "Int16"
  #     }, 
  #     "Float": {
  #       "opened": true, 
  #       "flags": {
  #         "names": "KEY_FLOAT", 
  #         "value": 16
  #       }, 
  #       "n_elements": 4, 
  #       "path": null, 
  #       "size": 8, 
  #       "type": {
  #         "id": 32, 
  #         "name": "type"
  #       }, 
  #       "id": 12, 
  #       "name": "Float"
  #     }, 
  #     "LongText": {
  #       "opened": true, 
  #       "flags": {
  #         "names": "KEY_VAR_SIZE", 
  #         "value": 16384
  #       }, 
  #       "n_elements": 4, 
  #       "path": null, 
  #       "size": 2147483648, 
  #       "type": {
  #         "id": 32, 
  #         "name": "type"
  #       }, 
  #       "id": 16, 
  #       "name": "LongText"
  #     }, 
  #     "TokyoGeoPoint": {
  #       "opened": true, 
  #       "flags": {
  #         "names": "KEY_GEO_POINT", 
  #         "value": 24
  #       }, 
  #       "n_elements": 4, 
  #       "path": null, 
  #       "size": 8, 
  #       "type": {
  #         "id": 32, 
  #         "name": "type"
  #       }, 
  #       "id": 17, 
  #       "name": "TokyoGeoPoint"
  #     }, 
  #     "Text": {
  #       "opened": true, 
  #       "flags": {
  #         "names": "KEY_VAR_SIZE", 
  #         "value": 16384
  #       }, 
  #       "n_elements": 4, 
  #       "path": null, 
  #       "size": 65536, 
  #       "type": {
  #         "id": 32, 
  #         "name": "type"
  #       }, 
  #       "id": 15, 
  #       "name": "Text"
  #     }, 
  #     "ShortText": {
  #       "opened": true, 
  #       "flags": {
  #         "names": "KEY_VAR_SIZE", 
  #         "value": 16384
  #       }, 
  #       "n_elements": 4, 
  #       "path": null, 
  #       "size": 4096, 
  #       "type": {
  #         "id": 32, 
  #         "name": "type"
  #       }, 
  #       "id": 14, 
  #       "name": "ShortText"
  #     }, 
  #     "Object": {
  #       "opened": true, 
  #       "flags": {
  #         "names": "KEY_UINT", 
  #         "value": 0
  #       }, 
  #       "n_elements": 4, 
  #       "path": null, 
  #       "size": 8, 
  #       "type": {
  #         "id": 32, 
  #         "name": "type"
  #       }, 
  #       "id": 2, 
  #       "name": "Object"
  #     }, 
  #     "Terms.memos_content_index": {
  #       "opened": true, 
  #       "sources": [
  #         {
  #           "id": 257, 
  #           "name": "Memos.content"
  #         }
  #       ], 
  #       "range": {
  #         "id": 256, 
  #         "name": "Memos"
  #       }, 
  #       "flags": {
  #         "names": "COLUMN_INDEX|WITH_POSITION|PERSISTENT", 
  #         "value": 33282
  #       }, 
  #       "n_elements": 4, 
  #       "path": "/tmp/groonga-databases/commands_object_list.0000103", 
  #       "type": {
  #         "id": 72, 
  #         "name": "column:index"
  #       }, 
  #       "id": 259, 
  #       "name": "Terms.memos_content_index"
  #     }, 
  #     "UInt8": {
  #       "opened": true, 
  #       "flags": {
  #         "names": "KEY_UINT", 
  #         "value": 0
  #       }, 
  #       "n_elements": 4, 
  #       "path": null, 
  #       "size": 1, 
  #       "type": {
  #         "id": 32, 
  #         "name": "type"
  #       }, 
  #       "id": 5, 
  #       "name": "UInt8"
  #     }, 
  #     "UInt32": {
  #       "opened": true, 
  #       "flags": {
  #         "names": "KEY_UINT", 
  #         "value": 0
  #       }, 
  #       "n_elements": 4, 
  #       "path": null, 
  #       "size": 4, 
  #       "type": {
  #         "id": 32, 
  #         "name": "type"
  #       }, 
  #       "id": 9, 
  #       "name": "UInt32"
  #     }, 
  #     "Terms": {
  #       "opened": true, 
  #       "token_filters": [], 
  #       "range": {
  #         "id": 0, 
  #         "name": null
  #       }, 
  #       "flags": {
  #         "names": "TABLE_PAT_KEY|PERSISTENT", 
  #         "value": 49153
  #       }, 
  #       "n_elements": 5, 
  #       "path": "/tmp/groonga-databases/commands_object_list.0000102", 
  #       "type": {
  #         "id": 49, 
  #         "name": "table:pat_key"
  #       }, 
  #       "id": 258, 
  #       "name": "Terms"
  #     }, 
  #     "UInt16": {
  #       "opened": true, 
  #       "flags": {
  #         "names": "KEY_UINT", 
  #         "value": 0
  #       }, 
  #       "n_elements": 4, 
  #       "path": null, 
  #       "size": 2, 
  #       "type": {
  #         "id": 32, 
  #         "name": "type"
  #       }, 
  #       "id": 7, 
  #       "name": "UInt16"
  #     }, 
  #     "Bool": {
  #       "opened": true, 
  #       "flags": {
  #         "names": "KEY_UINT", 
  #         "value": 0
  #       }, 
  #       "n_elements": 4, 
  #       "path": null, 
  #       "size": 1, 
  #       "type": {
  #         "id": 32, 
  #         "name": "type"
  #       }, 
  #       "id": 3, 
  #       "name": "Bool"
  #     }, 
  #     "Memos.content": {
  #       "opened": true, 
  #       "range": {
  #         "id": 15, 
  #         "name": "Text"
  #       }, 
  #       "flags": {
  #         "names": "COLUMN_SCALAR|PERSISTENT", 
  #         "value": 49152
  #       }, 
  #       "n_elements": 4, 
  #       "path": "/tmp/groonga-databases/commands_object_list.0000101", 
  #       "type": {
  #         "id": 65, 
  #         "name": "column:var_size"
  #       }, 
  #       "id": 257, 
  #       "name": "Memos.content"
  #     }, 
  #     "Time": {
  #       "opened": true, 
  #       "flags": {
  #         "names": "KEY_INT", 
  #         "value": 8
  #       }, 
  #       "n_elements": 4, 
  #       "path": null, 
  #       "size": 8, 
  #       "type": {
  #         "id": 32, 
  #         "name": "type"
  #       }, 
  #       "id": 13, 
  #       "name": "Time"
  #     }, 
  #     "Int64": {
  #       "opened": true, 
  #       "flags": {
  #         "names": "KEY_INT", 
  #         "value": 8
  #       }, 
  #       "n_elements": 4, 
  #       "path": null, 
  #       "size": 8, 
  #       "type": {
  #         "id": 32, 
  #         "name": "type"
  #       }, 
  #       "id": 10, 
  #       "name": "Int64"
  #     }, 
  #     "WGS84GeoPoint": {
  #       "opened": true, 
  #       "flags": {
  #         "names": "KEY_GEO_POINT", 
  #         "value": 24
  #       }, 
  #       "n_elements": 4, 
  #       "path": null, 
  #       "size": 8, 
  #       "type": {
  #         "id": 32, 
  #         "name": "type"
  #       }, 
  #       "id": 18, 
  #       "name": "WGS84GeoPoint"
  #     }, 
  #     "Memos": {
  #       "opened": true, 
  #       "token_filters": [], 
  #       "range": {
  #         "id": 0, 
  #         "name": null
  #       }, 
  #       "flags": {
  #         "names": "TABLE_HASH_KEY|PERSISTENT", 
  #         "value": 49152
  #       }, 
  #       "n_elements": 5, 
  #       "path": "/tmp/groonga-databases/commands_object_list.0000100", 
  #       "type": {
  #         "id": 48, 
  #         "name": "table:hash_key"
  #       }, 
  #       "id": 256, 
  #       "name": "Memos"
  #     }, 
  #     "Int8": {
  #       "opened": true, 
  #       "flags": {
  #         "names": "KEY_INT", 
  #         "value": 8
  #       }, 
  #       "n_elements": 4, 
  #       "path": null, 
  #       "size": 1, 
  #       "type": {
  #         "id": 32, 
  #         "name": "type"
  #       }, 
  #       "id": 4, 
  #       "name": "Int8"
  #     }
  #   }
  # ]
