database that allows to read and write from mutable array by index

Question

I'm looking for a database that allows me to store and retrive strings by an index. It should work just like a mutableArray but on disk. The database entries have a fixed length, the number of entries grows over time, up to about 100'000'000.

It doesnt matter if its sql, nosql or something else. The random read and writes should just be fast. I have had a look at levelDB and Kyoto but they store by key and not by array index.

Any hints are very much appreciated.

Can you explain the difference between a key and an index for your application? — Mat, Nov 15 '12 at 20:22
I'm sorry, that's about as clear as mud. A key can go 1:2:5:6 too. — Mat, Nov 15 '12 at 20:24
Im sorry there was a typo. I mean an array index: 0 1 2 3 4 5 ... — Thomas Bader, Nov 15 '12 at 20:26
You can still have an index key. In fact, it's pretty common to have an `ID` column for every table. If you _really_ want to, you can even renumber the IDs to keep them consecutive on deletion. — John Dvorak, Nov 15 '12 at 20:28
Note that an indexed access to an SQL database is very fast, and the point of a database is to have multiple indexes over the same set of rows. — John Dvorak, Nov 15 '12 at 20:30
Thanks Jan, I was hoping there was a db optimized for this particular thing. I suppose renumbering the IDs wont be fast. — Thomas Bader, Nov 15 '12 at 21:02

pbhd · Answer 1 · 2012-11-15T20:55:38.420

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Welcome to the ancestors. What you are looking for is implemented in a performant, reliable and well-tested manner by the good old Berkeley-Database. http://en.wikipedia.org/wiki/Berkeley_DB. Its meanwhile somehow under the control of Oracle, but still opensource as far as I know.

edited Nov 15 '12 at 20:55

answered Nov 15 '12 at 20:50

pbhd

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Thanks pbhd, thats exactly what I was looking for: http://www.stanford.edu/class/cs276a/projects/docs/berkeleydb/ref/am_conf/renumber.html – Thomas Bader Nov 15 '12 at 22:17

score 0 · Answer 2 · answered Nov 15 '12 at 20:24

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You might want to look at SQLite (http://www.sqlite.org/)?

answered Nov 15 '12 at 20:24

John

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Can you explain why? This answer isn't very helpful as it stands. – Michael Myers Feb 22 '13 at 15:54
Only from the standpoint that my experience with it (SQLite) seems to match the OP's requirements. I've no doubt there are better solutions available. – John Feb 22 '13 at 15:59

Thomas Matthews · Answer 3 · 2012-11-15T20:37:19.370

You want a relational database that supports indexing (most all RDBMs support indexing).
It will generate an "index" table that helps the DB access your data most efficiently based on fields you designate.

Since you added the tag c++, I'm assuming you want one that can interface with a C++ program. Many of them do.

Search the web for "relational database c++ (driver OR interface)".

Edit 1: A partial list of databases (in no order)

Oracle
MySQL
SQLite
Paradox
MS Access
Foxpro
http://www.opensitesolutions.com/services/databases.php

database that allows to read and write from mutable array by index

3 Answers3

Edit 1: A partial list of databases (in no order)