{"id":1199,"date":"2016-07-13T12:24:15","date_gmt":"2016-07-13T12:24:15","guid":{"rendered":"http:\/\/greenrobot.org\/?p=1199"},"modified":"2016-07-13T19:55:05","modified_gmt":"2016-07-13T19:55:05","slug":"android-orm-performance-2016","status":"publish","type":"post","link":"https:\/\/greenrobot.org\/android\/android-orm-performance-2016\/","title":{"rendered":"Android ORM Performance 2016"},"content":{"rendered":"

With greenDAO 3 released<\/a>, it’s time again to look at the Android ORM performance landscape and do some benchmarks. This time, we also tested\u00a0newer ORMs for SQLite like DbFlow, requery, SQLDelight, and SquiDB. Also, we had an extensive look at benchmarks done by others. Let’s get started with our results:<\/p>\n

<\/p>\n

\"Android<\/p>\n

As you can see greenDAO comes in first in for all operations while there is no distinct second place.\u00a0While this would be easy to claim, we are trying hard\u00a0to\u00a0present straight facts here. Objective benchmarks\u00a0are really difficult to do<\/a>\u00a0and we did our best to make this comparison fair. All our benchmarks are open source<\/a>, so you can verify the procedure for yourselves. Let us know if we can improve.<\/p>\n

Other ORM performance benchmarks<\/h2>\n

Critical minds may still have doubts, which is perfectly understandable because we still\u00a0might favor a specific\u00a0product. Granted, so let’s have a look at other popular benchmark projects by Raizlabs and Kevin Galligan.<\/p>\n

Benchmarks by Raizlabs<\/h3>\n

Raizlabs is an interesting case. In early 2015,\u00a0Raizlabs claimed\u00a0DbFlow<\/a>\u00a0to be the fastest Android ORM. Initially, they did not mention greenDAO at all. Soon, readers\u00a0left various comments asking about greenDAO. Thus Raizlabs added greenDAO in their benchmark suite, and commented that DbFlow was faster for inserts while greenDAO may have advantages when it comes to loading. Because concrete results still lacked, we ran Raizlab’s benchmarking app\u00a0with greenDAO included (smaller is better):
\n\"android-orm-benchmark-raizlabs-simple\"Seems like greenDAO\u00a0comes out fastest right away. A quick look at the code suggests\u00a0that\u00a0greenDAO’s\u00a0time for “Save” might further improve by exchanging the method “insertOrReplace” by just “insert”. But OK, let’s look at the other scenario called “Complex trial”:<\/p>\n

\"android-orm-benchmark-raizlabs-complex\"<\/p>\n

Fixing Raizlabs’s “complex trial” benchmark<\/h3>\n

In this setup, DbFlow\u00a0is the clear winner, right? But wait a second<\/strong>, why is greenDAO slower than OrmLite? And why is DbFlow loading\u00a0that fast? It’s time to have a closer look at their code. As it turned out, the “write” test made greenDAO use 101 transactions while the others used just a single one. That makes a big difference, so we fixed it<\/a>. The results from “load” test\u00a0are a little harder to understand, but in short, DbFlow already had all entities in memory after insert, so it did not have to load any entity from the database. It’s easy to\u00a0outperform others by leaps when you are the only one with a nicely filled cache in place. That’s why we filed an issue<\/a>\u00a0because we think the test setup does not make sense: either you test\u00a0caching or\u00a0loading, but never a mixture. Anyway, it was easy to make greenDAO use\u00a0its caching mechanisms in their setup. Here are the revised results:<\/p>\n

\"android-orm-benchmark-raizlabs-complex2\"<\/p>\n

Yep, fixing those seemingly small flaws in the benchmark\u00a0made a huge difference. In the revised benchmark, greenDAO clearly\u00a0outperforms\u00a0DbFlow for saving complex data. And\u00a0for loading, greenDAO can also\u00a0reuse previously inserted and thus “cached” entities in memory leading to close-to-zero “load” times.<\/p>\n

Benchmarks by Kevin Galligan<\/h3>\n

Kevin Galligan is a pioneer in\u00a0the Android ORM world: he’s the developer\u00a0of the Android Adapter for OrmLite and also\u00a0made an annotation processing extension for it. He gave a presentation at droidcon UK in late\u00a02015<\/a>\u00a0on Android ORMs accompanied by an blog post<\/a>\u00a0diving deeper also on ORM performance. His benchmarks<\/a> gave a different picture than ours, especially when looking at greenDAO. Let’s look a bit behind the scenes to understand what’s going on.<\/p>\n

The benchmarking code came initially from another developer\u00a0and\u00a0penalized OrmLite drastically. So Kevin\u00a0fixed it. Unfortunately, the original code also had a couple of problems regarding greenDAO, which were left unnoticed. We pushed a couple of pull requests to Kevin’s GitHub repository to fix those too:<\/p>\n