berkeley-db

DEADLOCK_WRAP error when using Berkeley Db in python (bsddb)

I am using a berkdb to store a huge list of key-value pairs but for some reason when i try to access some of the data later i get this error: try: key = 'scrape011201-590652' contenttext = contentdict[key] except: print the error <type 'exceptions.KeyError'> 'scrape011201-590652' in contenttext = contentdict[key]\n', ' F...

Looking for a lightweight java-compatible in-memory key-value store

Berkeley DB would be the best choice probably but I can't use it due to licensing issues. Are there any alternatives? ...

Choosing between Berkeley DB Core and Berkeley DB JE

I'm designing a Java based web-app and I need a key-value store. Berkeley DB seems fitting enough for me, but there appears to be TWO Berkeley DBs to choose from: Berkeley DB Core which is implemented in C, and Berkeley DB Java Edition which is implemented in pure Java. The question is, how to choose which one to use? With web-apps scal...

Best Python module for Berkeley DB?

According to the Python 2.6.5 docs [1], the bsddb module has been deprecated for removal in Python 3.0. What module/wrapper should I be using instead? [1] http://docs.python.org/library/bsddb.html ...

Berkeley DB replication: what's the typical latency?

I'm interested in using Berkeley DB replication to cache some data on some server nodes. What kind of update latency can I expect to see among the nodes? These will all be locally networked nodes. ...

Berkeley DB replication: upper limit on number of replicants?

I'm considering using Berkeley DB to cache some data on an application cluster. What's a reasonable upper limit on the number of nodes I can plan on Berkeley DB handling? Writing to the database will be from a single node. ...

Berkeley DB: btree prefix comparison for directory-like keys?

I'm going to index a BDB with keys that look a lot like directory paths ('/foo/bar', '/foo/baz', etc, with levels of slashes generally < 10). Does anybody have any experience with using a Btree prefix comparison routine[1] for this? Are the savings worthwhile? Any references to experience papers on this subject? [1] http://www.stanfor...

berkeley DB: can't compile c++ codes

When I compiled the sample codes of C++, I got following info: c++ excxx_example_database_read.cpp -o dbApp -I /usr/local/BerkeleyDB.5.0/include/ Undefined symbols: "Dbt::Dbt(void*, unsigned int)", referenced from: show_vendor(MyDb&, char const*)in ccnaWItX.o show_item(MyDb&, MyDb&, std::basic_string<char, std::char_traits...

How to get just the size of the value in BerkeleyDB?

Is there a way to get only the length (in bytes) of a value stored in BDB? I don't need the entire data array, only its size. ...

Writing an older version of Berkeley DB in Java

Is it possible to write out an older version of Berkeley DB using the Java interface? The version being 1.85/1.86. ...

Inserting records into Berkeley DB with Java

I can't seem to find sample code for constructing a Berkeley DB in Java and inserting records into it. Any samples? And I do not mean the Berkeley DB Java Edition either. ...

Best practices for deploying a high performance Berkeley DB system

I am looking to use Berkeley DB to create a simple key-value storage system. The keys will be SHA-1 hashes, so they are in 160-bit address space. I have a simple server working, that was easy enough thanks to the fairly well written documentation from Berkeley DB website. However, I have some questions about how best to set up such a sys...

What is the difference between the different BerkeleyDB versions, and which should I choose?

Many things depend on BDB. When I go to install the prepackaged software for my server, each piece of software seems to want a different version of BerkeleyDB. But it seems when I compile them I can specify a specific BDB version. (The software involved includes Postfix, OpenLDAP, and Cyrus IMAP.) I use BDB in python projects occaisio...

How fast is Berkeley DB SQL compared to SQLite?

Oracle recently released a Berkeley DB back-end to SQLite. I happen to have a hundreds-of-megabytes SQLite database that could very well benefit from "improved performance, concurrency, scalability, and reliability", but Oracle's site appears to lack any measurements of the improvements. Has anyone here done some benchmarking? ...

Why do I get wide character warnings from Perl when I insert in a Berkeley DB?

I'm running an experiment on Berkeley DBs. I'm simply removing the contents from DB a and reinserting the key-value pairs into DB b. However, I am getting Wide character errors when inserting key-value pairs into this DB b. Help? ...

Is it possible to access a BDB from pure Java?

Hi I'm trying to access "cert8.db" mozilla file which is a BDB database. I know that there are bindings for languages, Java among them, but I'm trying to build a multiplatform app so I think that using JNI such as this one would be a problem. Thanks in advance. ...

Insert MANY key value pairs fast into berkeley db with hash access

Hi, i'm trying to build a hash with berkeley db, which shall contain many tuples (approx 18GB of key value pairs), but in all my tests the performance of the insert operations degrades drastically over time. I've written this script to test the performance: #include<iostream> #include<db_cxx.h> #include<ctime> #define MILLION 1000000 ...

Does anyone have any experience using berkeley db with PHP?

I have to access and write to some berkeley db files that other applications share. I really haven't found anything out there about using this with PHP. It really doesn't seem very popular. Does anyone have any links or resources that I might be able to use to get things rolling? Thanks! ...

Improve Performance in BDB oracle

I wanted to get Btree statistics from a database implemented in Sleepycat API's for Berkely Database. Also can anyone suggest a few hacks to make the bdb database access faster if it's only being used in READONLY environment? Also setting cache size, both from EnvironmentConfig and DataBaseConfig doesn't increase the actual size of cache...

Bulk reads using Berkeley DB, C++ STL interface

I'm using the C++ STL API to Berkeley DB 4.8, and I'm able to use bulk retrieval for a db_map or db_multimap const iterator created using begin(), but not one created from find() (or lower_bound() for multimaps). I appreciate for single item random access uses of find() would be a waste to use bulk retrieval, but I want to access many r...