data-synchronization

问题 I need to Synchronize some tables between the App SQLite Database an a MS SQL Database hosted online. I already have a COLUMN (IsSync) on each table that allows me to know which ROWS are pending sync (i.e. SELECT * FROM Locations WHERE IsSync=0) The Locations table is one of the tables that I need to synchronize as soon as the table got updated/inserted. This table contains GPS Location data (Lat,Lng,Accuracy,Speed, etc) that is inserted EACH AND EVERY 3-4 SECONDS (15 records each minute).

问题 I'm just getting into Meteor, and am similarly new to MongoDB. I am accustomed to syncing MySQL dbs (production vs dev) for running tests of new features with near-live data. At present, I don't know how to do this with meteor. From this (http://docs.meteor.com/#meteormongo) I gather that I can use a mongoDB shell to work with my local db, but from looking at http://docs.mongodb.org/manual/mongo/, I haven't yet figured out if this is the path I should be following to sync things up for Meteor

问题 I have a web application that relies on a MySQL database, for which I am thinking of building an iPhone app. This app would allow users to browse/insert/update/delete data on their account on the web application. The easiest way would be to build the iPhone app simply as an interface for the web app, ie each operation requires to be connected to the web. However, I would like the iPhone app to have its own "offline" version of the database. This would not only allow the user to work offline,

问题 Anybody has any ideas or references on how to implement a data persistence layer that uses both a localStorage and a REST remote storage: The data of a certain client is stored with localStorage (using an ember-data indexedDB adapter). The locally stored data is synced with the remote server (using ember-data RESTadapter). The server gathers all data from clients. Using mathematical sets notation: Server = Client1 ∪ Client2 ∪ ... ∪ ClientN where, in general, any record may not be unique to a

问题 Anybody has any ideas or references on how to implement a data persistence layer that uses both a localStorage and a REST remote storage: The data of a certain client is stored with localStorage (using an ember-data indexedDB adapter). The locally stored data is synced with the remote server (using ember-data RESTadapter). The server gathers all data from clients. Using mathematical sets notation: Server = Client1 ∪ Client2 ∪ ... ∪ ClientN where, in general, any record may not be unique to a

问题 In my previous question on this portal, I had asked about some insight about syncing data between SQL Server and key-value based data repositories. In lieu of the same problem (one way real-time synchronization from SQL to HBase or any other database), I need to take care of some performance and latency considerations and did not find a very foolproof way of doing it. We have multiple SQL 2008 data shards where data is updated from various sources and processed by many processes at the same

问题 does anyone know if and how you can sync CoreData apps with iCloud? If I understand the Apple iCould instructions right you can not sync CoreData, can you? 回答1: Given that you tagged this with Cocoa, I suggest that you watch the video for WWDC 2011 Session 315 - "What's New in Core Data on Mac OS X". For iOS, check out Session 303 - "What's New in Core Data on iOS". These will answer all of your questions regarding Core Data and iCloud. Since this is still under NDA, that's the most I can

问题 Here is the scenario. 2 web servers in two separate locations having two mysql databases with identical tables. The data within the tables is also expected to be identical in real time. Here is the problem. if a user in either location simultaneously enters a new record into identical tables, as illustrated in the two first tables below, where the third record in each table has been entered simultaneously by the different people. The data in the tables is no longer identical. Which is the

问题 I am writing an application that depends on data from various sites/service, and involves performing calculations based on data from these different sources to produce an end product. I have written an example class with two functions below that gathers data from the two sources. I have chosen to make the functions different, because sometimes we apply different authentication methods depending on the source, but in this example I have just stripped them down to their simplest form. Both of

问题 I have a primary database containing table A and a secondary database containing another copy of A. Each time my application starts it checks all the rows of table A in the primary database and updates the rows of A in secondary database. The need for this ugly behaviour is support for a legacy database however this operation on each start is starting to be very cpu expensive. I have found out a timestamp (also called row version by Microsoft) can store when rows have been updated. My