Resolve database todos

Database.md

@@ -35,9 +35,13 @@ assigned. Other columns are:
 - _deletedAt_ -- assignment cannot be deleted due to possible numerous
   dependencies, but can be hidden from the users; published assignments have
   NULL value, deleted ones have time of deletion
-- _version_ -- @todo
-- _isBonus_ -- @todo
-- _pointsPercentualThreshold_ -- @todo
+- _version_ -- which version is the current assignment; changed on every
+  assignment details update
+- _isBonus_ -- assignment is bonus one and its points are not counted into
+  overall group score
+- _pointsPercentualThreshold_ -- number of points which solution has to gain to
+  get at least some points; if solution gained fewer points then threshold,
+  score will be zero
 
 ## Comment
 
@@ -71,7 +75,8 @@ inheritance mechanism, but it's currently not being used.
   medium and hard
 - _isPublic_ -- flag if the exercise is publicly visible to all supervisors or
   only to author
-- _description_ -- @todo
+- _description_ -- description for supervisors which is not visible to students
+  after assignment
 
 ## ExerciseFile
 
@@ -121,7 +126,9 @@ data:
   is hidden (only for members)
 - _externalId_ -- external identifier of the group (or NULL), for example
   course code like NPRG042
-- _deletedAt_ -- @todo
+- _deletedAt_ -- groups cannot be deleted due to possible numerous
+  dependencies, but can be hidden from the users; active groups have NULL
+  value, deleted ones have time of deletion
 
 ## GroupMembership
 
@@ -165,7 +172,7 @@ API server. Each group or user belong to exactly one instance. User permissions
 are only valid in his instance.
 
 - _admin_ -- key referencing administrator user entity
-- _name_ -- @todo
+- _name_ -- visible name of the instance
 - _description_ -- Markdown styled textual description
 - _isOpen_ -- flag if new user can register themselves in this instance
 - _isAllowed_ -- flag if the instance cen be used or is disabled for all users
@@ -379,11 +386,12 @@ that will be stored too.
 
 ## TaskResult
 
-@todo
+Represents result of one task from particular job execution and has to belong
+to TestResult entity through _testResultId_ column.
 
-- _taskName_ -- @todo
-- _usedTime_ -- @todo
-- _usedMemory_ -- @todo
+- _taskName_ -- identification of task which is connected with this result
+- _usedTime_ -- used execution time needed for this task evaluation
+- _usedMemory_ -- used memory needed for this task evaluation
 
 ## TestResult
 
@@ -459,4 +467,4 @@ application.
 - _vimMode_ -- turn vim mode keybinding on in text editor used by web
   application
 - _defaultLanguage_ -- default language which will be used in web application
-- _openedSidebar_ -- @todo
+- _openedSidebar_ -- left sidebar will be opened after login