![\"Simplicity](\"\/wp-content\/original-assets\/2016\/june\/hg-simplify-your-life-with-couchbase-mobile\/simplicity_quote.jpg\")
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Photo courtesy of Wesley Fryer<\/a> with permission under license CC BY-SA 2.0<\/a><\/p>\n \u00a0<\/p>\n tl;dr<\/strong><\/p>\n Couchbase Mobile<\/a> is easy to use, works completely standalone, yet provides enterprise-class scaling when you need it. You should try it.<\/p>\n This will be my second official post here at Couchbase<\/a>. I\u2019ll be blogging about more practical issues coming up. But for the moment, I\u2019m going to indulge in a little higher level discourse.<\/p>\n<\/div>\n I\u2019ve been programming for a long time. Over the last several years, I\u2019ve really gotten into mobile, but I\u2019ve worked in a lot of other areas.<\/p>\n<\/div>\n Still, I\u2019d guess, before joining Couchbase, I had an average understanding of databases. Or, I should say, relational databases. Somehow achieving 6th normal form always seemed kind of cool, but I\u2019ve never actually needed to worry about it.<\/p>\n Even so, for development, relational databases (and hence, SQLite on mobile) seemed like the way to go.<\/p>\n<\/div>\n In this post, I\u2019m going to talk about why I\u2019ve changed my mind, and why I think you should too.<\/p>\n<\/div>\n<\/div>\n<\/div>\n Years ago, relational databases had pretty much won the day over other technologies. To the point that SQL, which is actually the name of a language, became almost synonymous with the term database.<\/p>\n<\/div>\n The world has changed a lot with the explosion of both the Web and mobile. This includes the kinds of data, and how it\u2019s accessed. Databases had to change, too. This gave birth to the NoSQL universe.<\/p>\n<\/div>\n I won\u2019t go into the larger picture of NoSQL. For reference, here are a few resources to help understand what NoSQL is1<\/a><\/sup>2<\/a><\/sup>, how it compares to relational databases3<\/a><\/sup>4<\/a><\/sup>, and more advanced topics5<\/a><\/sup>. Obviously, there\u2019s a lot more you could dig into.<\/p>\n<\/div>\n<\/div>\n<\/div>\n Couchbase Mobile (or CBM) is a complete package, including a stand-alone embedded database. (The stand-alone part is actually called Couchbase Lite.) CBM\u2019s core architecture puts in squarely in the NoSQL camp.<\/p>\n<\/div>\n I want to focus on two particularly compelling reasons why I believe CBM should be your first choice for mobile apps: ease of use, and architectural flexibility. I\u2019ll talk more in terms of using CBM from the start of a project. The same points make a strong case for switching to CBM, even in a mature app.<\/p>\n<\/div>\n Both iOS and Android rely on SQLite for their standard databases. SQLite is an excellent open-source relational database. It\u2019s just not that easy to use.<\/p>\n<\/div>\n I went over to the Android developer portal to take a look at the current docs on using SQLite. Here\u2019s the beginning of the first paragraph after the intro:<\/p>\n<\/div>\n And here\u2019s an example chunk of code for creating a database:<\/p>\n<\/div>\n Fun, right?<\/p>\n<\/div>\n Now, don\u2019t get me wrong. Android is an awesome technology bundle. SQLite is best-in-class. But apps need to store data. And if I\u2019m trying to get a project off the ground, I don\u2019t want to spend my time thinking about schema design and stuffing SQL statements into strings.<\/p>\n<\/div>\n In contrast, this is roughly what it takes to start with Couchbase Mobile:<\/p>\n<\/div>\n And here\u2019s code (minus boilerplate stuff) to store some new data:<\/p>\n<\/div>\n That\u2019s not a completely fair comparison. The Google sample has some of the extra bits you need to do things properly. On the other hand, the Couchbase sample already has data going into the database!<\/p>\n<\/div>\n The real point has to do with how simple it all is. It\u2019s so much easier to map natural structures in the code (Java objects, in this case) to the constructs needed for the database. The ease of mapping allows CBM to take care of a lot of other details for you, too. The code snippet above isn\u2019t much more than it would take to to serialize a Java object to a file!<\/p>\n<\/div>\n Couchbase is a document database, meaning you store a complete, semi-structured object as the fundamental data chunk (as opposed to a row in a table). More precisely, Couchbase stores JSON objects. JSON is lightweight and flexible. It handles arrays. Objects can be extended without breaking anything. It\u2019s just nicer.<\/p>\n<\/div>\n Contrast that with trying to glue some inflexible tables together to map to an object of any complexity. Whether you do it yourself in SQL, or you pull in a library to help, it\u2019s not a pretty sight.<\/p>\n<\/div>\n<\/div>\n Couchbase Mobile gives you flexibility in two important ways, structure, and scalability.<\/p>\n<\/div>\n CBM is “schema-less”. That shows in the ease-of-use. In the code sample, you can see the document structure gets created implicitly. No need to define tables or name columns.<\/p>\n<\/div>\n Beyond that, schema-less means you can easily change your data structures without the migration headaches.<\/p>\n<\/div>\n To illustrate these points, imagine starting with a user profile that contains one phone number for each person. The two figures show how that might look as a SQLite table, and a JSON document.<\/p>\n<\/div>\n Think for a minute about managing that transition. I\u2019m not even going to try to show how the code might look.<\/p>\n<\/div>\n By contrast, with JSON, you have this diagram:<\/p>\n<\/div>\n All it takes is overwriting the phone number entry with an array. It\u2019s even easy to handle backward compatibility. You could simply check at runtime whether the phone entry was a single value or an array.<\/p>\n<\/div>\n<\/div>\n Up to now, everything I\u2019ve talked about works entirely stand-alone on a device. That\u2019s powerful, and takes care of a lot of uses. Some mobile databases stop there. They work stand-alone only.<\/p>\n<\/div>\n If you\u2019re using a database, chances are some backend is at least a nice to have. Or, it could be critical to your success. Simply providing backups to make switching devices effortless comes to mind, if nothing else.<\/p>\n<\/div>\n Once you start needing a backend, you have to worry about several new challenges. This brings me to my last point about Couchbase Mobile. CBM has many features to address off-device use.<\/p>\n<\/div>\n Going back to what I find most compelling, the concern that stands out here is scalability. What\u2019s it going to cost to handle 10,000 users, or maybe even 100,000 or a million? Can your architecture even support off-device operations without a lot of rework?<\/p>\n<\/div>\n CBM includes something called Sync Gateway. Sync Gateway (SG) has some cool uses just in combination with Couchbase Lite. Where it really shines is as a replication endpoint for Couchbase Server<\/a>. Couchbase Server is an enterprise-ready, heavy-duty NoSQL package already used in major installations. You can read more about Sync Gateway here<\/a>. \u00a0The following image gives an idea of how the components fit together.<\/p>\n<\/div>\n Bottom line, CBM doesn\u2019t box you into a corner. Getting started is easy, and you can do it knowing CBM has the flexibility to handle your needs as you progress.<\/p>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n CBM is a modern, document-based, highly scalable NoSQL solution for mobile.<\/p>\n<\/div>\n CBM works great in isolation, on-device.<\/p>\n<\/li>\n Couchbase provides a complete back end, if you want it.<\/p>\n<\/li>\n The data format maps easily to native representations.<\/p>\n<\/li>\n<\/ul>\n<\/div>\n Together, that gives you a solution that\u2019s easier to use for almost any project. Use it as a convenient store for user preferences. Use it to deliver a static bundle of data along with your app. Or, use it when you want to shoot for millions of active users. Enjoy the simplicity, and know you have the flexibility to adapt and scale as you need it.<\/p>\n<\/div>\n<\/div>\n<\/div>\n There are a lot of details behind the concepts I\u2019ve discussed. I\u2019ve included some references for further exploration, although I\u2019ve relied on many more for this post.<\/p>\n<\/div>\n\nIn the beginning<\/h2>\n
\n\n\n\n\n\nSetting the stage<\/h2>\n
\n\n\n\n\nWhy Couchbase Mobile<\/h2>\n
\n\n\n\nEase of Use<\/h3>\n
\n\nOne of the main principles of SQL databases is the schema: a formal declaration of how the database is organized.<\/span><\/div>\n\n\n\n\r\n
public class DictionaryOpenHelper extends SQLiteOpenHelper {\r\n\r\n private static final int DATABASE_VERSION = 2;\r\n private static final String DICTIONARY_TABLE_NAME = \"dictionary\";\r\n private static final String DICTIONARY_TABLE_CREATE =\r\n \"CREATE TABLE \" + DICTIONARY_TABLE_NAME + \" (\" +\r\n KEY_WORD + \" TEXT, \" +\r\n KEY_DEFINITION + \" TEXT);\";\r\n\r\n DictionaryOpenHelper(Context context) {\r\n super(context, DATABASE_NAME, null, DATABASE_VERSION);\r\n }\r\n\r\n @Override\r\n public void onCreate(SQLiteDatabase db) {\r\n db.execSQL(DICTIONARY_TABLE_CREATE);\r\n }\r\n}<\/code><\/pre>\n<\/div>\n<\/div>\n\n\n\n\n\n\r\n
manager = new Manager(new AndroidContext(this), Manager.DEFAULT_OPTIONS);\r\n database = manager.getDatabase(\"crud\");<\/code><\/pre>\n<\/div>\n<\/div>\n\n\n\n\r\n
Document document = database.createDocument();\r\n String documentId = document.getId();\r\n\r\n Map\n\n\n\n\nFlexibility<\/h3>\n
\n\nStructure<\/h4>\n
\n\n\n\n![\"Single](\"\/wp-content\/original-assets\/2016\/june\/hg-simplify-your-life-with-couchbase-mobile\/rdb2.png\")
<\/div>\n<\/div>\n\n![\"Simple](\"\/wp-content\/original-assets\/2016\/june\/hg-simplify-your-life-with-couchbase-mobile\/json2.png\")
<\/div>\nSuppose the requirement changes. You want to make it possible to include more than one phone number. In the relational case, you\u2019d want to migrate to something like what\u2019s shown in this diagram:<\/div>\n<\/div>\n\n![\"Array](\"\/wp-content\/original-assets\/2016\/june\/hg-simplify-your-life-with-couchbase-mobile\/rdb3.png\")
<\/div>\n<\/div>\n\n\n\n![\"JSON](\"\/wp-content\/original-assets\/2016\/june\/hg-simplify-your-life-with-couchbase-mobile\/json3.png\")
<\/div>\n<\/div>\n\n\nScalability<\/h4>\n
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<\/div>\n<\/div>\n\n\nWrapping up<\/h2>\n
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\n\nPostscript<\/h2>\n
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