I am going to use Core Data and SQLite together for managing big amount of data on iOS devices. Is that good solution? Are there other ways?
Sqlite can handle very large ammount of data. and core data also use sqlite in backend. SO your approach is right. You should go for this.
for more detail see this:
http://www.sqlite.org/limits.html
There are two ways in which you can write data to file in iOS.
One is NSUserDefaults and the other is Core Data.
NSUserDefaults is not the proper way for storing large amounts of data. It's used to store application settings and temporary data.
Core Data is the proper way for storing and managing large ammounts of data.
Related
I have several big plists in my app. I use them to get necessary input data to my app. While app is running, this data used in various random visual representations. Also, I have favorites feature, where I save some favorite pieces of data. For favorites feature I use CoreData. I transfer some object from my "runtime" data to CoreData and save it.
But should I transfer all data from plists to CoreData, when I launch app for the first time? Or is it ok, to use plists to get data from them every launch?
For example, if we'd talking about reading app. We have some text file on disk. Should I transfer all file to CoreData, when launch first time? Or is it ok, just to save user bookmarks to CoreData?
Core data and plist both are used for store the data. so, if you get data from plist or core data at every launch, there is no problem at all. But if you want to manage complex relational database then you should use core data or sqlite. so, choose storing system as per your requirement like if you want to store user's default credential then you can use nsuserdefault and if you use it to store complex data then also it will work fine but you will possible to face trouble to face some kind of functional operation. So, main concern and your answer there is no difference you get in performance whatever database system you used.
Hoe this will help :)
If you have to only read the data or update all data from plist allmost all the time plist may be ok, also it will be more easy to access then Core Data
Both plist and Core data can be used as persistant storage, but Core Data will have some addtional benifit like i have listed below:
Data stored in the Core Data is pretty secure, so if you can store some sesitive information in the Core Data, data store in plist can be seen directly in some ways.
If you have to perform some insert,update,delete or search on the data it will be better on the Core Data instead of plist.
If you want something like relation or mapping between data it will be possible with Core Data only
So based on the requirement you can choose your storage options
Background:
I have an app that retrieves a list of restaurants from a database, each have an individual array of basic information about them (hours, name, address, etc). I would like to retrieve that information from the server on the apps first load, but then have it stored within the app itself, with either NSUserDefaults or Core Data, since the information is unlikely to change. The max number of restaurants I would be storing is about 25, is that a small enough data collection to use NSUserDefaults?
I have looked at similar questions with storing data with over 1,000 records, but I am only storing a small array.
Question:
NSUserDefaults is much easier to use than Core Data, so if possible I would like to avoid using Core Data. In my case, will there be a performance problem if I am storing my list of restaurants in NSUserDefaults instead of Core Data?
Depends on the
size
structure of data
requirements re integrity of the data
Just an Array of 10 or 20 "restaruants" I would certainly store in NSUserDefaults. But only when I am sure that this will never become more complex. Because when you later extend your model but started off with NSUserData then you may remain with NSUserDefaults just because you avoid migrating it to Core Data during the upgrade of an installed app.
So for more complex structures including references and when you have further plans with your app towards more functionality that may require more entities, then you should go for Core Data from start.
BTW, it is not that complicated as you may think.
However, instead of abusing NSUserDefaults, you could simply write an NSArray to file using -writeToFile:atomically: and -initWithContentsOfFile: to read them in.
NSUserDefaults is not intended for data, it's for storing simple key-value pairs like user settings and flags. Core Data is a bit hard to learn at first, but definitely worth it, even for simple applications.
If it really is a small, simple data set that won't change very often, you can also store some data in a local plist (i.e. save NSArray or NSDictionary to plist using writeToFile method). This isn't very different from using NSUserDefaults in terms of performance, although I think it's cleaner and easier to manage. If it never changes you can also include the plist with your app resources in XCode by creating a plist file and filling it in with your data.
Considering the amount of the data, user default or a specific plist/json file are all good. CoreData is definitely overkilling.
As far as I know, in iOS we can keep data in JSON files, .plist or .xml files, NSUserDefaults (which is basically a .plist file), SQLite database, or Core Data (which can be set to have different data stores, but usually we use .sqlite files).
I am currently supposed to make my app be able to work with tens of thousands of records, and I am using Core Data. The thing is that my client told me Core Data is probably not the best solution for large datasets, and I am confused because as far as I know, if we have so many records we should obviously not keep them all in memory (in NSMutableArray or other collection objects), and Core Data seems to be the best and fastest way to implement all the functionality.
Please let me know if you have the same problem in the past and which solution you chose.
I have used core data for a 64 thousand object database, worked perfectly as expected. Not sure exactly what you are trying to do but core data will work fine.
I am building an application that recovers JSON data (1000-2000 lines) from a website. It's basically just a bunch of arrays and values, nothing fancy. What would be the best way to store this information and use it between the views? Should I create a local sqlite database, write to file or just send the information from view to view using prepareforsegue?
I would think the latter is faster and easier to implement, but I'm not sure if it's easier to use after (I'm new to IOS).
Thank you !
I'm using Core Data with Magical Record. It easily maps your JSON objects into NSObjects which are then persisted into Core Data. It is thread safe and very powerful.
Or you can map it yourself into NSObjects of your choice without actually persisting them or saving them anywhere which is much easier in some cases. It is a good way to go as well.
Both methods looks OK . Now it depends whether your JSON data is big enough to slow down the app.
Sqlite Database is easy to implement to store large information in your app.but if you want to increase performance of app to access data locally you can use core data to store data because it providing object relationship to store data in app that is easy to access and store data.but now it is depends on you
There are various ways for iPhone applications to save data (for example: NSUserDefault, XML, document, SQLite, etc.).
Our company always uses NSUserDefault to save data. However, I don't think NSUserDefault is very good because in my experience, it has been slow.
I am curious how you store data for your applications and when you recommend using each of the different methods. Please share your experiences that will help me to understand the advantages and disadvantages of these different storage types and develop a more efficient application for my users.
You can store small data in NSUserDefaults but when you have large database then you need sqlite or coredata for storing the database. use of coredatabase is good for big database this is provided by apple and it is to efficient in accessing database.
NSUserDefaults or document directory is used for small database(suppose need to store user name for single user or some other info).
You just need to know about sql queries to store data in a SQLite3 Database or You can use Core Data for back end storage. Core Data is one of the best options to use for storing data.
NSUserDefault should be used for storing small information.
You can use NSUserDefaults for storing any small data which you want to persist when your application closes. This you can use to store login details but yes if it is be secured, use keychain. You can definely use NSUserDefaults for storing setting options.
SQLite database is any easy way to store large data. Core Data is best option. but you can use SQLite if your application data is not too large.
SQlite Database can also be used to store BLOB data e.g. to store pdf file bytes downloaded from server and whenever you want to use it, just write those bytes to pdf file. This will also keep data security since BLOB data in SQLite cannot be viewed.
Its good to use coreData for large data storage in the IPhone Memory space. ITs a wrapper on top of the database which helps us to store in the form of objects.....
U can find many examples on this...