Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.

Lokijs

511,198 views

Published on

Introducing LokiJS - an embeddable in-memory javascript datastore for node.js, browser and cordova/phonegap

Published in: Software
  • Dating direct: ❶❶❶ http://bit.ly/39mQKz3 ❶❶❶
       Reply 
    Are you sure you want to  Yes  No
    Your message goes here
  • DOWNLOAD THAT BOOKS INTO AVAILABLE FORMAT (2019 Update) ......................................................................................................................... ......................................................................................................................... Download Full PDF EBOOK here { https://urlzs.com/UABbn } ......................................................................................................................... Download Full EPUB Ebook here { https://urlzs.com/UABbn } ......................................................................................................................... Download Full doc Ebook here { https://urlzs.com/UABbn } ......................................................................................................................... Download PDF EBOOK here { https://urlzs.com/UABbn } ......................................................................................................................... Download EPUB Ebook here { https://urlzs.com/UABbn } ......................................................................................................................... Download doc Ebook here { https://urlzs.com/UABbn } ......................................................................................................................... ......................................................................................................................... ................................................................................................................................... eBook is an electronic version of a traditional print book that can be read by using a personal computer or by using an eBook reader. (An eBook reader can be a software application for use on a computer such as Microsoft's free Reader application, or a book-sized computer that is used solely as a reading device such as Nuvomedia's Rocket eBook.) Users can purchase an eBook on diskette or CD, but the most popular method of getting an eBook is to purchase a downloadable file of the eBook (or other reading material) from a Web site (such as Barnes and Noble) to be read from the user's computer or reading device. Generally, an eBook can be downloaded in five minutes or less ......................................................................................................................... .............. Browse by Genre Available eBooks .............................................................................................................................. Art, Biography, Business, Chick Lit, Children's, Christian, Classics, Comics, Contemporary, Cookbooks, Manga, Memoir, Music, Mystery, Non Fiction, Paranormal, Philosophy, Poetry, Psychology, Religion, Romance, Science, Science Fiction, Self Help, Suspense, Spirituality, Sports, Thriller, Travel, Young Adult, Crime, Ebooks, Fantasy, Fiction, Graphic Novels, Historical Fiction, History, Horror, Humor And Comedy, ......................................................................................................................... ......................................................................................................................... .....BEST SELLER FOR EBOOK RECOMMEND............................................................. ......................................................................................................................... Blowout: Corrupted Democracy, Rogue State Russia, and the Richest, Most Destructive Industry on Earth,-- The Ride of a Lifetime: Lessons Learned from 15 Years as CEO of the Walt Disney Company,-- Call Sign Chaos: Learning to Lead,-- StrengthsFinder 2.0,-- Stillness Is the Key,-- She Said: Breaking the Sexual Harassment Story That Helped Ignite a Movement,-- Atomic Habits: An Easy & Proven Way to Build Good Habits & Break Bad Ones,-- Everything Is Figureoutable,-- What It Takes: Lessons in the Pursuit of Excellence,-- Rich Dad Poor Dad: What the Rich Teach Their Kids About Money That the Poor and Middle Class Do Not!,-- The Total Money Makeover: Classic Edition: A Proven Plan for Financial Fitness,-- Shut Up and Listen!: Hard Business Truths that Will Help You Succeed, ......................................................................................................................... .........................................................................................................................
       Reply 
    Are you sure you want to  Yes  No
    Your message goes here

Lokijs

  1. 1. LokiJS Javascript In-Memory Database @tech_fort
  2. 2. ??? WHAT ???
  3. 3. WHY? ● In-memory is faster than I/O ● SQLite is great but there is no NoSQL / document-oriented equivalent of it ● SQLite is cumbersome in a mobile / embedded context (who can be bothered with SQL in a mobile app?) ● Phonegap and Node-Webkit apps would benefit from a javascript database where data is plain javascript objects, and persisted on disk as JSON. ● Traditional databases rely on platform libraries which impose portability contraints and version conflicts. Data is frequently 'locked-in' ● For many applications NoSql is a far more preferable and better performing approach than relational data when working with complex object stores which are built for consumption.
  4. 4. Enter Loki ● LokiJS is compatible with browser and node.js ● Persistence to disk on inserts/updates/deletes (in node.js, node-webkit and cordova environments) ● Available on bower and npm ● Extremely low footprint - 28KB uncompressed!! ● Supports indexing, and uses Binary Search for search granting fast performance ● NoSQL jargon: documents, collections, map, reduce ● Compatibility: dependency free, native, pure javascript runs across many js environments ● Portablility : entire database state can be serialized as a single entity to be restored in an identical state or transferred across environments as a single JSON entity. ● Performs better than similar products (NeDB, TaffyDB, PouchDB etc.), and it's much smaller
  5. 5. Sample Usage var loki = require('lokijs'),   db = new loki('demo.json'),   doctors; doctors = db.addCollection('doctors', { indices:  ['name']}); doctors.insert({ name: 'David Tennant', doctor:  10}); doctors.insert({ name: 'Matt Smith', doctor: 11}); doctors.insert({ name: 'Peter Capaldi', doctor:  12});
  6. 6. Updates ● Updates are optional. LokiJS holds references to objects so there's no need to update an object. However, update(obj) can be called to force re-indexing of collections.
  7. 7. Querying ● Querying is quite intuitive: doctors.get(index); doctors.find({ doctors: 10});  doctors.find({ doctors: { '$gte' :  9}});
  8. 8. Querying (Mongo Style) Mongo style queries will benefit from access to index optimizations. ● Declarative query definition via a query object ● Current supported operators include $eq, $gt, $gte, $lt, $lte, $ne, $regex, $in, $contains ● Supports dot notation for deep querying
  9. 9. Querying (Javascript views) ● Means of specifying complex 'edge case' query filters ● Write your own javascript filter function which can be anonymous or persisted with a name as a view. ● Has access to the entire (possibly hierarchical) document object ● Used for chained queries and dynamic views ● Worse performance / cant be serialized (need to be reattach to dynview on load)
  10. 10. Fluent API You can resort to functions to obtain your data by leveraging the built-in ResultSet class: doctors.chain()   .find({ doctor: { '$gte': 9 }})   .where(function (obj) { return  obj.name.indexOf(“t”) != ­1; })   .simplesort(“name”)   .data(); // this exposes the data
  11. 11. Dynamic Views Views hold references to filtered data to optmize search even further (avoiding to scan the entire collection). Thet maintain freshness of query results optimally as they are notified of data inserts, updates and deletes. var view = doctors.addDynamicView(“latestDoctors”); view.applyFind({ doctor: { '$gte': 8}}); view.applySort(function (a, b) {   return a.doctor < b.doctor; }); // inspect the data console.log(view.data());
  12. 12. Persistence ● Loki now supports three primary persistence methods : filesystem (Node), localStorage (cordova/browser), and indexedDB (cordova/browser) ● A new persistence adapter interface allows for interoperability with other popular and/or custom data stores. Community members can develop and submit adapters for popular datastores and submit a pull request to share them. ● Autosave/Autoload capabilities exist for you to optionally utilize for automating and bootstrapping persistence.
  13. 13. IndexedDB Support for browsers ● Loki now implements an indexedDB App/Key/Value Catalog, implemented using the new persistence adapter interface. ● This catalog can contain as many databases as your storage quota allows, organized by application. This allows grouping, listing and querying the catalog of databases by 'application' groups. ● Loki's indexedDB adapter supports console use for easily managing your catalog from a browser console.
  14. 14. Summary ● Use collection operations (insert, update, delete) for document-oriented maintenance ● Use collection operations (find, where) for optimal query performance ● Use resultset with fluent-like syntax for defining complex query-oriented pipelines ● Use dynamic view for defining views which inherit the resultset pipeline, yet avoid needing to requery
  15. 15. RoadMap ● MRU cache / Key-value store option ● TCP and HTTP Wrappers to enable running LokiJS on dedicated (virtual) machines ● Replication ● Horizontal scaling ● MongoDB API subset compatibility
  16. 16. Links: Web: http://lokijs.org Github: https://github.com/techfort/LokiJS Contributors: Joe Minichino Dave Easterday @tech_fort

×