I have a Google Nexus 5. Every time I do a system update, I see this message:
Android is upgrading...
Optimizing app [x] of [y]
I understand that ART is compiling my apps. What I don't understand is why. What happened to the previous compilations?
Why Does ART Compile Apps After Upgrade?
Question
Answer
Because the ART compiler can get better each version after your OS gets upgraded. If Android makes any improvements to ART including bug fixes, the apps will need to go through the same processes as the compile part of the installation.
Q & A
DNS queries are cached permanently, how to reliably clear DNS cache on Android 7+?
Android large empty storage marked as full (new phone)
Compatibility Feasibility Speed and use of High Capacity MicroSd Card for adaptable swapping and linking apps?
Can OTG HUB charge with connected charger more than 0.5A?
How to activate 'Do not disturb' when connected to a specific Bluetooth device
Call barring in Android
How to use an external sdcard as internal in Android Lolipop 5.1.1?
How to create and use multiple partitions on external SD card with different filesystems (Ext4, exFAT, NTFS)?
How to move 7GB ext4 partition on external SD card to 30GB partition on another SD card?
there is an internal problem with your device
Android Verified Boot and generation of vbmeta image
Open Google Docs in Browser
HDR option grayed out on Samsung A50 camera
Is there a way to change the system date/time settings to a non-Gregorian calendar, e.g. Hijri, Jewish?
Keep playlist always in shuffle
Firefox add-on is shown beside search box on desktop, but where is it on Android?
Is it possible to encrypt system partition with custom rom?
How can one reduce Microsoft Outlook's background mobile data usage?
Dial phone, screen blanks -> can't hang up
Looking for help choosing the correct stock recovery.img file for my phone
Android large empty storage marked as full (new phone)
Compatibility Feasibility Speed and use of High Capacity MicroSd Card for adaptable swapping and linking apps?
Can OTG HUB charge with connected charger more than 0.5A?
How to activate 'Do not disturb' when connected to a specific Bluetooth device
Call barring in Android
How to use an external sdcard as internal in Android Lolipop 5.1.1?
How to create and use multiple partitions on external SD card with different filesystems (Ext4, exFAT, NTFS)?
How to move 7GB ext4 partition on external SD card to 30GB partition on another SD card?
there is an internal problem with your device
Android Verified Boot and generation of vbmeta image
Open Google Docs in Browser
HDR option grayed out on Samsung A50 camera
Is there a way to change the system date/time settings to a non-Gregorian calendar, e.g. Hijri, Jewish?
Keep playlist always in shuffle
Firefox add-on is shown beside search box on desktop, but where is it on Android?
Is it possible to encrypt system partition with custom rom?
How can one reduce Microsoft Outlook's background mobile data usage?
Dial phone, screen blanks -> can't hang up
Looking for help choosing the correct stock recovery.img file for my phone
Topics
2D Engines 3D Engines 9-Patch Action Bars Activities ADB Advertisements Analytics Animations ANR AOP API APK APT Architecture Audio Autocomplete Background Processing Backward Compatibility Badges Bar Codes Benchmarking Bitmaps Bluetooth Blur Effects Bread Crumbs BRMS Browser Extensions Build Systems Bundles Buttons Caching Camera Canvas Cards Carousels Changelog Checkboxes Cloud Storages Color Analysis Color Pickers Colors Comet/Push Compass Sensors Conferences Content Providers Continuous Integration Crash Reports Credit Cards Credits CSV Curl/Flip Data Binding Data Generators Data Structures Database Database Browsers Date & Debugging Decompilers Deep Links Dependency Injections Design Design Patterns Dex Dialogs Distributed Computing Distribution Platforms Download Managers Drawables Emoji Emulators EPUB Equalizers & Event Buses Exception Handling Face Recognition Feedback & File System File/Directory Fingerprint Floating Action Fonts Forms Fragments FRP FSM Functional Programming Gamepads Games Geocaching Gestures GIF Glow Pad Gradle Plugins Graphics Grid Views Highlighting HTML HTTP Mocking Icons IDE IDE Plugins Image Croppers Image Loaders Image Pickers Image Processing Image Views Instrumentation Intents Job Schedulers JSON Keyboard Kotlin Layouts Library Demos List View List Views Localization Location Lock Patterns Logcat Logging Mails Maps Markdown Mathematics Maven Plugins MBaaS Media Menus Messaging MIME Mobile Web Native Image Navigation NDK Networking NFC NoSQL Number Pickers OAuth Object Mocking OCR Engines OpenGL ORM Other Pickers Parallax List Parcelables Particle Systems Password Inputs PDF Permissions Physics Engines Platforms Plugin Frameworks Preferences Progress Indicators ProGuard Properties Protocol Buffer Pull To Purchases Push/Pull QR Codes Quick Return Radio Buttons Range Bars Ratings Recycler Views Resources REST Ripple Effects RSS Screenshots Scripting Scroll Views SDK Search Inputs Security Sensors Services Showcase Views Signatures Sliding Panels Snackbars SOAP Social Networks Spannable Spinners Splash Screens SSH Static Analysis Status Bars Styling SVG System Tags Task Managers TDD & Template Engines Testing Testing Tools Text Formatting Text Views Text Watchers Text-to Toasts Toolkits For Tools Tooltips Trainings TV Twitter Updaters USB User Stories Utils Validation Video View Adapters View Pagers Views Watch Face Wearable Data Wearables Weather Web Tools Web Views WebRTC WebSockets Wheel Widgets Wi-Fi Widgets Windows Wizards XML XMPP YAML ZIP Codes