Collecting Data
The program provides optimal performance with various data feeds. Its behavior depends on the data feed connected; there exist three kinds of data feeds - data feeds that provide real-time only, data feeds that provide both history and real-time and data feeds that provide history only.
See the Built-In Data Sources table for more detailed information on data feeds.
The program's behavior depending on the data feed type is described below:
Data feed provides real-time only
Most brokers do not provide history data. In this case the program receives only real-time data and stores it in the local database. The data is saved immediately, at the same time as it is charted and may be used in the future. The program creates 1 minute and 1 day resolutions automatically and stores them in the database along with ticks.
All other resolutions are generated from stored data. I.e. if we need a 100 tick chart, the program automatically builds it from existing ticks. If a 2 minute chart is required, the program builds it from 1 minute data. In case of gaps in data 1 tick, 1 minute or 1 day must be imported correspondingly.
See the Importing Data section for more detailed information.
Data feed provides both history and real-time
Most professional data vendors as well as a number of advanced brokers provide history data for the ultimate trader convenience.
The amount and quality of data provided varies from vendor to vendor, though; see the Built-In Data Sources table for a general overview of history data feeds.
MultiCharts demonstrates the best performance with such data vendors, freeing the user from the need to download missing data manually.
The history data is stored in the local database and needs minimal effort for reuse, as only missing data has to be downloaded instead of the entire period. Besides, as data is stored locally, it is accessible even when vendor servers are not; all real-time data from the vendor is stored in the database as well, so no repeated queries must be sent when charts are created again. This cuts down on the Internet traffic and accelerates work. 1 tick, 1 minute and 1 day resolutions are stored in the database.
Data feed provides only history data
There exists a multitude of End-of-Day and intraday historical data vendors. Data from such vendors is used by in-depth analysis by experienced traders or for filling gaps in data from other vendors. When this data is used on its own, without requiring combination with data from other vendors, we insist on importing data into symbols of real-time only vendors, such as Universal DDE.
This guarantees that the data will not be mixed up with already existing data and will be charted exactly the way it was downloaded. The program saves to the database 1 tick, 1 minute and 1 day resolutions and generates all others from them. When data is imported, existing data in the database will be overwritten by the data from the file if the timestamps are the same.
