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Questions tagged [mapdb]

MapDB provides concurrent Maps, Sets and Queues backed by disk storage or off-heap memory

MapDB provides concurrent Maps, Sets and Queues backed by disk storage or off-heap memory. It is a fast and easy to use embedded Java database engine. And it is completely free under Apache License. MapDB is free as speech and free as beer under Apache License 2.0.

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I can't save DB file with MAPDB

I doing a project with GWT and use mapDB for DB. if I create a new object i can read it, but when close the project and restart I lost all data, I see that it never creates a file to save. this is my code: Method for create and add new object…
Mr Alsi
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Is RocksDB and LevelDB just like Riak?

I have a question regarding some NoSQL databases. In Ehcache we have for example the JCache API, in MapDB the Map Interface and in Riak KV we have a own process with clusters. How do I exactly find out which database fits to which implementation…
user12541507
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How to use HTreeMap to populate a List

I am trying to use HTreeMap from mapDB to populate a List of million entries in a CSV file, but every time I insert data into the List, the previous entry is overwritten for the HTreeMap. The only way to avoid overwriting an HTreeMap in the final…
Aashish
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MapDb treeset key doesn't come with expire property

I use mapdb's direct memory to act as my off-heap memory. Because there are a lot of sortedset in my application, so I used mapdb treeset cache mechanism to store my values. Code as below: @PostConstruct private void initDbEngine() { try { …
CharlieShi
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Comparing an ArrayList of Integer to more than one ArrayList to extract common values

I have one ArrayList of Integer, extracted from a MapDB map, with this code: ArrayList idOffUser=users.get(myUser).getOffers(); It's a list of ids. I have another ConcurrentNavigableMap from the same db, called auctions. In this map for…
JamieITGirl
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How to read data in MapDB files

Is there a way to see the data saved in MapDB files like I do with MySQL? I'm putting some data in a ConcurrentNavigableMap through a web application and I need to check if they're saved correctly. I tried to open the DB file but it's obviously…
JamieITGirl
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mapd-connector for connecting-to-the-server-and-rendering-the-visualization

Hi I am beginner for the Mapd database , i started to practicing the CURD Operation in mapd database its working fine, and right now i am started to working on link rendering visualization in the mapd database using the Vega , so i followed the link…
Richard A
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MapDB is thread-safe?

Is it true that the latest version of MapDB is thread-safe? I couldn't find anything concrete at Google and their website doesn't say anything about locking.
Daniel
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What's the proper way to create a DB with MapDB?

I have to use MapDb for a Java project but im only familiar with Mysql. Im a litte confused about the creation of the db. My Db should contain user information and posts by user and comments on posts and other similarities. How should i create the…
Pjotr Raskolnikov
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Is there is any way to Read mapdb map from hdfs?

I want to access mapdb maps straight from HDFS, without copying it to local file system. Is it possible? Is there is any other approach by which I can read these maps without using local file system?
Akash Mahajan
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MapDB - Evolving schema/Changing saved objects

I saved some objects in mapdb like: import org.mapdb.*; //open (or create) database File file = new File(“dbFileName”); DB db = DBMaker .newFileDB(file) .make(); //use map Map map = db.hashMap(“mapName”); map.put(1,…
uylmz
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MapDB cleared cached items on GC

I'm evaluating MapDB for an application. I create the DB following way. DB db = DBMaker.fileDB(new File("mapdbtest1")).cacheHashTableEnable() .cacheSize(50000).closeOnJvmShutdown() …
TechCrunch
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MapDB file backup

I'm using a file-backed MapDB which I create like this: File dbFile = new File("db"); DBMaker.newFileDB(dbFile) .closeOnJvmShutdown() .make(); I noticed that there are 3 files being created: db db.p db.t I need a way store and retrieve a…
amitayh
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How does newTempHashMap work in mapdb?

How does newTempHashMap work in mapdb? Is it just a file-backed hash map or is there an in-memory caching layer?
Pinch
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Why won't MapDB work when re-openning database?

So I created a database that worked like this: static class Record implements Serializable { final String action; final String categoryOfAction; final String personWhoPerformedAction; final Long timeOfOccurrence; public…
rudy
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