If it's possible, I'm interested in being able to embed a PostgreSQL database, similar to sqllite. I've read that it's not possible. I'm no database expert though, so I want to hear from you.
Essentially I want PostgreSQL without all the configuration and installation. If it's possible, tell me how.
Run postgresql in a background process.
Start a separate thread in your application that would start a postgresql server in local mode either by binding it to localhost with some random free port or by using sockets (does windows support sockets?). That should be fairly easy, something like:
system("C:\Program Files\MyApplication\pgsql\postgres.exe -D C:\Documents and Settings\User\Local Settings\MyApplication\database -h 127.0.0.1 -p 12345");
and then just connect to 127.0.0.1:12345.
When your application quits, you can always send a SIGTERM to your thread and then wait a few seconds for postgresql to quit (ie join the thread).
PS: You can also use pg_ctl to control your "embedded" database, even without threads, just do a "pg_ctl start" (with appropriate options) when starting the application and "pg_ctl stop" when quitting it.
You cannot embed it, nor should you try.
For embedding you should use sqlite as you mentioned or firebird rdbms.
Unless you do a major rewrite of code, it is not possible to run Postgres "embedded". Either run it as a separate process or use something else. SQLite is an excellent choice. But there are others. MySQL has an embedded version. See it at http://mysql.com/oem/. Also several java choices, and Mac has Core Data you can write too. Hell, you can even use FoxPro. What OS you on and what services you need from the database?
You can't embed it as a in process type thing like sqlite etc, but you can easily embed it into your application setup using Inno setup at http://www.innosetup.org. Search their mailing list archive and you will find someone did most of the work for you and all you have to to is grab the zipped distro and you can easily have postgresql installed when the user installs your app. You can then use the pg_hba.conf file to restrict the server to local host only. Not a true embedded DB, but it would work.
PostgreSQL is intended to run as a stand-alone server; it's probably possible to embed it if you hack at it hard and long enough, but it would be much easier to just run it as intended in a separate process.
HSQLDB (http://hsqldb.org/) is another db which is easily embedded. Requires Java, but is an excellent and often-used choice for Java applications.
Anyone tried on Mac OS X:
http://pagesperso-orange.fr/bruno.gaufier/xhtml/prod_postgresql.xhtml
http://www.macosxguru.net/article.php?story=20041119135924825
(Of course sqlite would be my embedded db of choice as well)
Well, I know this is a very very very old post, but if anyone has nowadays this question, I would refer to:
You can use containers running Postgres. Here's a post that could be helpful, doing something along this line using R:
https://rsangole.netlify.app/post/2021/08/07/docker-based-rstudio-postgres/?utm_source=pocket_mylist
Take a look at duckdb https://duckdb.org/docs/installation/ It is relatively new and still needs to mature. But it works pretty much like an embedded database ("In-process, serverless"), with bindings for several languages (Python, R, Java, ...)
Related
I have a server application using Node, and sometimes I need to run some script in it. Some examples of scenarios when this would be necessary:
During development, I need to create many entries in the database to simulate an use case.
In production, some bug happened and some information was not correctly stored in the DB, I may need to backfill it.
The way I know how do it in node is to deploy some instance of the server with an endpoint that contains the code to be run.
It is interesting to use the node server because it already has a lot of code that I can reused, for example DAO and safe create/delete funcitons.
Django has a interactive Python interpreter that does this job, but I do not know any similar way to it in Node.
Other strategies of doing this use cases are very welcome.
During development, you can just go with debugging, although that requires triggering a breakpoint. Alternatively, if it's just about your database, there are better external programs to interact with your database.
To actually answer your question: Node does have a VM module to run code and even a REPL module to help writing custom REPLs. This does require some work to link up your APIs though, but doable.
As for how you actually interact with that REPL, there are several options. Using a raw socket (and Telnet), a terminal on your site communicating over a WebSocket, a simple HTTP endpoint, ...
You can add scripts in your package.json to handle this with a path to the script. For example "seed:db": "node ./src/seeder.js -i", "drop:db": "node ./src/seeder.js -d" where the i an d flags will be used to determine if i am inserting or deleting, and can be gotten with process.argv[2]
when i create a postgresql database and create tables and columns and even insert data into the columns. I cant restart my machine without losing the created databases and all the data.
i have tried changing a coupe things in the configuration file but nothing helped.
I also have to reset the password for postgres everytime I restart my machine. I mainly use mongodb I am just learning postgreSQL just so I can use it if I ever need to in the future. I am runing a Linux machine QubesOS. I have a few problems like this useing QubesOS. every tutorial I watch everybody uses Macs. Which a mac seems good and all kinda a mix between windows and linux The best of both worlds. Easy package installs and terminal control but I dont want to trade my linux machine for a Mac I would much rather just fix these problems I am having with PostgreSQL on my linux machine
You ran into an important security feature of QubesOS: All data modifications are discarded on shutdown of a so called "Qube". They are reset to their original state.
But there is the exception of data kept in some very special directories.
If you convince your data base packages to put their data into these directories, it will be preserved over reboots of your data base Qube:
Read this documentation for more information.
Here is the problem: We have a client that uses Progress Openedge database, we need to execute queries on this database from our servers.
Currently the drivers are installed on our Windows server, and the PHP code uses ODBC to run the queries.
Now we would like to move the code to a Linux server. We tried before to work with their linux drivers but that attempt has failed.
The question is, Is it possible somehow to run PHP code on a linux server, this code communicates with the Windows server, runs the query on the Windows server, and return the results to Linux?
How would you access to this problem.
Thanks!
Yes, it's possible. Your question boils down to "how can my Linux server ask my Windows server to do something" (where the "something" happens to be "talk to a database"), and there are a variety of ways to accomplish that. You could run a web service (RESTful or SOAP) on the Windows server, for example.
Make sure you think about security: if you deploy a service on your Windows server that lets remote clients modify a database, you have to be mindful of which remote clients are allowed to use that service. The last thing you want to do is accidentally allow random strangers to run arbitrary queries against your database.
We have a Knowledgebase Article detailing some setup procedures for Linux installations; it also has a video explaining some aspects of the setup. If the other answered haven't provided a complete solution for you, hopefully our article can at least get you started in the right direction.
Also keep in mind that depending on your version of OE, the driver libraries may be different.
I created a server using c++ and want to run this server as daemon on linux..
How do I do this?
Thanks in advance...
There are many ways to daemonize a process. It is quite common that server implementations provides a switch to daemonize it at startup.
If you do not wish to implement such a feature, command-line tools exists such as this one : http://software.clapper.org/daemonize/.
I don't mean to sound condescending but did you try a google search, there is a heap of info on this out there, the first link I found: (http://www.enderunix.org/docs/eng/daemon.php)
You can use dup2() on Linux to make the FD's a bit easier to handle.
You may also want to look into using something like inetd to manage your server
I'm a newbie JavaScript programmer who wants to experiment with server side JavaScript using Node.Js on my Mac
I downloaded NodeJs and the wizard installed it, but now I can't see it in my applications?
1) How do I open it and start using it? Do I do it from the command line? if so, how do I start?
2) Can I connect it to a MySQL database I have installed with MAMP?
Thanks if you can help
To start node, you open a terminal and type:
/path/to/node scriptname.js
Depending on how you installed node, the actual location of node may vary. You should figure that out. You should probably add that path to your PATH environment variable. If you do this then you can simply type
node scriptname.js
There are plenty of samples around the net. As for mysql connectivity, check this out.
I am in pretty much in the same boat as you are, and I highly recommend you to watch the meetup talk by Ryan Dahl on http://nodejs.org/
It is only about an hour long, but it pretty shows you how you can use it for your own non-blocking applications.
In terms of driver for accessing SQL, you will need to install NPM http://npmjs.org/
You can do a quick search http://search.npmjs.org/, on the support for MySQL. Because node.js is still relatively new to the scene, you will see quite a bit of choices competing to meet your goal