AMALTHEA Trace Database

The AMALTHEA Trace Database stores traces in a way that – especially for graphical user interfaces – information can be extracted efficiently.

General information

The Database is stored as SQLite Database with extension .atdb.
All numbers are stored as integer values.

Database structure

The Database contains a mixture of statically and dynamically defined tables, which are described in more detail below:

• Static
  • MetaInformation
  • Entity
  • EntityInstance
  • EntitySource
  • EntityType
  • EventType
• Dynamic
  • EventTable

MetaInformation

MetaInformation contains a simple key-value list of information about the Trace:

• Fields
  • Name: Text – Primary Key
  • Value: Text

By now, the following list of keys is defined:

• db_version: version of the AMALTHEA Trace Database scheme with syntax “v#.#.#”. Current version is "v0.2.0"
• events_written: The amount of events stored in the database
• input: path to the file, from which the information was produced
• time_base: The base time in which time-values are stored

Entity

Entity contains information about the Entities used in the database.

• Fields
  • Id: Number – Primary Key
  • Name: Text - Case-Sensitive Unique
  • EntityType: Number – 1:n Reference to EntityType-Table
  • HasEvents: Number – possible values
    • 1: Events for that Entity were produced
    • null: No Events for that Entity were produced
  • EventTableName: Text – The name of the table in which, the events for that entity are stored

EntityType

EntityType contains information about the EntityTypes used in the database.

• Fields
  • Id: Number – Primary Key
  • Name: Text

By now, the following EntityTypes are defined:

• Core
• EventChain
• Interrupt
• InstructionBlock
• Process
• Runnable
• Scheduler
• SemaphoreAccess
• Semaphore
• Signal
• Stimulus
• Task

EventType

• Fields
  • Id: Number – Primary Key
  • Name: Text

The list of EventTypes which may occur can be retrieved from “AMALTHEA_BTF_Specification”.

EntitySource

EntitySource contains information about which Entity has events caused by which other Entities.

• Fields
  • EntityId: Number – Primary Key; EntityId references the Entity events occurred for
  • SourceEntityId: Number – Primary Key; SourceId references the Entity, which caused the event

EntityInstance

EntityInstance contains information about the time span an instance of an entity was active.

• Fields
  • Id: Number – Primary Key
  • EntityId: Number – Reference to an entity
  • EntityInstanceId: Number – Instance number for that entity
  • TimeFrom: Number – Start-Time of the instance
  • TimeTo: Number – End-Time of the instance

EventTables

There is a dynamic amount of EventTables. An EventTable contains events of 1 or more entities. The information which entity is part of which EventTable is stored in Entity-Table.

• Fields
  • Id: Number – Primary Key, ascending id-number for each EventTable
  • TimeStamp: Number – Time at which the event occurred in base_unit defined at MetaInformation
  • Remainder: Number – Time modulo 1000 to get a more precise value in cases it is required
  • SQCNR: Number – A strictly ascending sequential number telling the order of event at same time stamp
  • EntityId: Number – Reference to entity, for which the event occurred
  • EntityInstanceId: Number – Instance of the entity
  • SourceEntityId: Number – Reference to entity, which caused the event
  • SourceEntityInstanceId: Number – Instance of the source entity
  • EventTypeId: Number – Reference to EventType
  • Value: String – Additional unstructured data for an event like e.g. the written value in case of a Signal Write event