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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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Mapdb stops after adding 32 items into the hashmap

Here is the definition for my objects: public class Tuple_comparable implements Serializable, Comparable { public String arg1_surface; public String arg1_type; public boolean arg1_type_equals; public String…
Daniel
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hashmap vs treemap in mapdb: how to compare them?

Recently I started playing with MapDB, and learning about its interesting properties. As I understand now, it has three major data types: BTree, Hashmap and Hashset. Something which is a little obscure to me is that, when it is better to use Hahsmap…
Daniel
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MapDB file types

I have a problem with mapDB version 1.0.6. When i create a database i end up with two files with the same name but with different file types. One is for example IRTree with file type FILE and the other is IRTree with file type .p Having said that,…
Bill Soumakis
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Creating Map from large file

I have a very large file (10^8 lines) with counts of events as follows, A 10 B 11 C 23 A 11 I need to accumulate the counts for each event, so that my map contains A 21 B 11 C 23 My current approach: Read the lines, maintain a map, and update the…
shyamupa
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Am I using MapDB in the best way?

I have a question regarding MapDB. The code excerpt below is from part of a bigger system for managing voxel data, the specifics are not important. Usage of the maps I create is frequent and large in scope, in that these maps typically store…
MukRaker
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How to retrieve data from mapDB database, without override it every time?

I'm developing a GWT web application very similar to Doodle.com I need to store in a database some informations about Events and Users. It is a project for a university exam and we have to use mapDB for the persistent datas. The problem we have is…
Gio Bact
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Java: Using mapDB, writing in Database overwrites previous entry

I use mapDB to store my Data, which are inserted in maps. I followed the instructions on mapDB-Site and was able to set up an Database and also fill it with values. But my problem is right here, I insert my data into the maps and then call the…
Alika87
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MapDB collection size issue

I'm using MapDB 0.9-snapshot. I have some collection containing several millions of records String->String. My problem is that the method size() on such ConcurrentMap(s) takes a lot of time and a lot of memory (I have even an OutOfMemory error). Any…
Brad Stallion
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How can i put something in database?

package faq.server; import java.util.ArrayList; import java.util.concurrent.ConcurrentMap; import org.mapdb.DB; import faq.shared.Category; import faq.shared.CategoryComponent; import faq.shared.CategoryIterator; import…
mr strap
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Looking for a crash-safe queue in java

I'm building a Java application that will run on a battery-powered, cellular-enabled device (not a mobile phone by the way), and needs to send commands to a server. These commands are in the form of JSON-objects, so they can easily be serialized and…
Marten Jacobs
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Is MapDB ready for production?

Is MapDB ready for production? Are people using it in prod? What are your experiences? http://www.mapdb.org/ thanks
CodingHero
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