One of the appropriate uses for sqlite3 is "in-memory databases". This sounds like a really useful tool for my C++ applications. Does anyone have an example of how this is done in C or C++? I'm specifically looking for a canonical way to slurp several flat-files into an in-memory database, then do some joins. ...
I'm using SqlServer to drive a WPF application, I'm currently using NHibernate and pre-read all the data so it's cached for performance reasons. That works for a single client app, but I was wondering if there's an in memory database that I could use so I can share the information across multiple apps on the same machine. Ideally this wo...
I am looking for an in-memory relational (SQL) database for Java (something like HSQLDB), whose whole state I can serialise. wholeDatabase.serialize(outputStream); newCopyOftheDatabase.loadFrom(inputStream); Or maybe the DB only uses a byte[] that I give it on initialization: byte[] memory = new byte[10 *1024*1024]; new InMemoryDatab...
I'm currently trying to pick a database vendor. I'm just seeking some personal opinions from fellow database developers out there. My question is especially targeted towards people who: 1) have used Main Memory DB (MMDB) that supports replicating to disk (hybrid) before (i.e. ExtremeDB) or 2) have used Versant Object Database and/...
There are quite a few independent and not-so-independent studies comparing traditional RDBMSs but I haven't managed to find any good material on in-memory databases. I am primarily interested in ones specialized for OLTP. So far, I managed to find generic white papers on TimesTen and MySQL Cluster, but I have yet to see a head-to-head c...
Hi all, I need an embedded/In Memory Database which support multithread access. Thanks! Leo ...
Dear ladies and sirs. I wonder if there is an in-memory database implementation, where the same in-memory database instance can be used across multiple AppDomains. The motivation. Like many folks out there, we have integration tests for our client-server application. There are several test modes, from the most heavy one - the real life...
We have a SQL 2005/2008 database that has a table with a computed column. We're using the computed column as a discriminator in NHibernate so having it in the database is proving to be very useful. In order to gain the benefits of faster integration tests, I'd like to be able to run our integration tests against an in-memory database su...
I was just think that now it is common to have enough RAM on your database server to cache your complete database why are the specialist in memory database (e.g TimesTen, see also Wikipedia page) that were all the rage a few years ago not being used more? It seems to be that as time go on, none disk based databases are being used less...
I just found "Has anyone published a detailed comparison between different in-memory RDBMSs?" that is related to my question. TimesTen (see also) is a In-Memory Database from oracle. It has a lot going for it including. Fast, consistent response time High transaction throughput Standard SQL, no application rewrite Persi...
Before I invest the time in modifying the SubSonic 3 source, I figured I ask to see if I'm missing something simple. Is it possible to use the SubSonic 3 Repository with migrations on a SQLite In-Memory database? I couldn't find a way to force the DbDataProvider to keep the connection open so the In-Memory SQLite database doesn't vanish...
Continuing some themes in this question, I would like to know if I could get a performance of O(log n) on the size of the table from somes sqlite queries. The first would get the mth element of a table ordered by weight: select id, weight from items order by weight limit 1 offset m The second would do the opposite, get mth position o...
Are there any DBs for Java that can be run in an embedded mode with some tables being stored in-memory while loading others from disk? H2 and JavaDB seem to be the two leaders for Java DBs and I know they both have an in-memory mode, but do they make you load the whole DB into memory or can you decide on a table-by-table basis? ...
I'm investigating options to create a database cache using HSQLDB in an in-memory mode. The idea is that the cache will be queried from a PHP application and the query will be passed to a Java application that runs the HSQLDB database. Now, I've been thinking this through and I can't see any efficient way to pass the data from Java bac...
In an in-memory database, is it necessary to close ResultSets, Statements and Connections? My Java program uses HSQLDB to create a "memory table" and populate it with data, which it later queries. There is no persistence. Everything is done in memory. The program is single-threaded and only has one database connection (i.e. no database...
I'm using derby as an embedded database. Furthermore, I'm using it's in memory database option for my unit tests. What I can't figure out is how to properly shut down (A quick look at the code) the derby database. I beleive I have it working for a standard database but I'm getting different exceptions when attempt similar code on a in-...
Trying to learn a bit about PDO and is going through this tutorial. It has the following snippet of code: <?php try { $db = new PDO('sqlite::memory'); echo "SQLite created in memory."; } catch(PDOException $e) { echo $e->getMessage(); } When I run this I get the following exception message: SQLSTATE[HY000] [14] unabl...
We have a 10 thousand row table that has just 2 columns, a primary key and a second column that keep state. The problem is that we need this state to be replicated across 3 physical locations in the US(about 2000 miles apart), in near real time or as fast as practically possible over a network. Any of the 3 locations can update the state...
Are there are good in-memory transactional databases that support LINQ and SQL Server persistance? I'd like to create a full representation of a large data store in memory and have it commit to a SQL Server Database in a lazy fashion, but still keep some level of fault tolerance by scaling it out horizontally. I don't want to rely on n...
I'm looking for some STL, boost, or similar container to use the same way indexes are used in databases to search for record using a query like this: select * from table1 where field1 starting with 'X'; or select * from table1 where field1 like 'X%'; I thought about using std::map, but I cannot because I need to search for fields t...