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provide real-time only, data feeds that provide both history and real-time and data feeds that provide history only.
See the [[<span style="color: red;">'''LINK'''</span> /102_Builtin_DataSources.html name=""; Category:Built-in_Data_Sources|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:
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 [[<span style="color: red;">'''LINK'''</span> /107_Data_Import.html name=""; |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 [[<span style="color: red;">'''LINK'''</span> /102_Builtin_DataSources.html name=""; Category:Built-in_Data_Sources|tableDatafeeds list]] for a general overview of history data feeds. The program 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.
