I have installed ejabberd on an AWS EC2 instance and am using the smack library to connect to it with my android app. At the moment the ejabberd server is using mnesia as the database, however I want to perform some complex queries on some of the data (mainly the MUC room names), as SQL will predominantly the best solution for this, I was wondering if it was possible to replicate the required data to an external MySQL database that I could then query.
Is this possible or am i better looking at a different approach to this problem?
There is no module built into ejabberd to replicate data in Mnesia to MySQL. However, the usual approach is to use the backend you need for each feature. If you want mod_muc to store data into MySQL instead of Mnesia, you can just change the backend to odbc (which means it will store data for that module in a relational database).
You can refer to ejabberd documentation for MUC module: http://docs.ejabberd.im/admin/guide/configuration/#modmuc
Once your MySQL is configured and schema is loaded, you can set db_type to odbc on a case by case basis to choose MySQL for that module.
Related
I was wondering if it is possible to create custom MySQL servers in VB.NET while working in visual studio at runtime so that if the server already exists it connects and if it isn't there, the code creates the server. I have searched for this everywhere but couldn't find anything. I would appreciate it a lot if someone guides me to the right path.
You could certainly write some .net code to start a MySQL server on your Windows box when an attempt to connect fails. You simply get a cmd.exe console with administrator privileges and give the command net start mysql.
But MySQL must already be installed on the box for that to work.
You might investigate Sqlite. It provides SQL locally to a .net program, storing your tables in a file called whatever.db. It has very similar .net API access to MySQL's Connector/Net and SQL Server's connector. It's in a NuGet package.
I don't completely understand your "custom MySQL servers" requirement. Sqlite gives you a way to use SQL in your application without connecting to a shared server. That may do what you need.
MySQL does have a CREATE SERVER statement in its SQL dialect. The purpose of this statement is to create a connection to another, remote, MySQL server. With that connection you can use the FEDERATED storage engine to access tables in the remote server. Of course, there is no way to run this CREATE SERVER statement unless your program is already connected to a MySQL server.
With respect, your "task which states to create a server at runtime" doesn't make much sense. Is there more to this requirement? What workflow needs this step? Is it part of the installation of some application software on a new box?
sorry if title is not so clear, probably I am not finding what I need due I do not know how to search
I have few MySQL servers is separated online servers (from different wordpress) and I want to load some of the data on those databases/tablets into a SQL database located on Azure.
inside Azure portal itself I do not see where to establish external connections, neither at server level, neither at database level
I download and install Microsoft SQL Server Management Studio, connect to the server, I can see my databse and the master one, Security with logins, and Integration Service Catalog, nothing else.
I was looking for something like:
https://www.jetbrains.com/help/go/db-tutorial-connecting-to-ms-sql-server.html#step-3-connect-to-microsoft-sql-server-with-datagrip
but nowhere ...
maybe something like this:
https://www.devart.com/odbc/mysql/docs/microsoft_sql_server_manager_s.htm
but no Servers objects option available on my SSMS
Can be this done?
Note: Azure database is a basic wfor now, if that is a limitation
Some choices.
In your SQL Server Management Studio create a linked server pointing to each MySQL instance. You found the instructions for that. https://www.devart.com/odbc/mysql/docs/microsoft_sql_server_manager_s.htm But it probably will not work in Azure SQL Server; you don't have access to the underlying Windows OS to install stuff like MySQL ODBC drivers, which you need. (You could ask Azure techsupport if they can help.)
In each MySQL instance, try creating a federated table connection to appropriate table in SQL Server. That cross-vendor federation stuff only works in MariaDB, however; MySQL's federation only goes MySQL <--> MySQL.
Write yourself a purpose-built extract / transform / load (ETL) program, and arrange to run it every so often. Program it to connect to all the servers involved, retrieve the data needing to be transferred from your MySQL servers, and update / insert that data on the SQL server.
(edit) You may be able to use command-line SQL client programs. mysqldump, with its --compatible option, may generate usable INSERT statements in a file. You then may be able to use sqlcmd to run those INSERTs on your Azure server. It's going to take some hacking, and may take using sed(1) or awk(1) to make the MySQL output compatible with SQL Server.
I believe the third option is the most robust one for production use.
I have a task to Migrate MySQL DB to Oracle (its my requirement) i tried to Migrate using SQL developer as defined in below link.
https://www.packtpub.com/books/content/migrating-mysql-table-using-oracle-sql-developer-15
As the DB is huge, the constraints are not copied properly from MySQL to Oracle, i need to define/alter/add constraints explicitly, which is time consuming (SQL developer migrates data 300rec/min from mysql to Oracle) & the entire procedure, views, functions is need to re write.
How can i ensure that data has migrated properly or not.?
Is this is a right approach to migrate?
Should i move to any tool which helps to Migrate? If yes please suggest the tool..!!
Or it is the right thing to Move from MySQL to Oracle.
Thanks in Advance.
No specific answer, but some genaral thoughts based on my experiences with migration.
I've found that there normally isn't one tool that does the whole migration job well, and by whole job I mean:
Fast
Handles all data types, scenarios
And that is from Oracle to Oracle!!
Last project we tried Oracle Golden Gate, and found there were issues with that.
We always end up with a hybrid approach, somethings like:
Extract all DDL manually and pre-create objects - there are weaknesses in the stagndard tools that confound them when extracting DDL, e.g. we found 10g expdp did not handle some quirky PLSQL well, so we resorted to extracting this ourselves.
Some tables work well with SQL Loader, others with GG, others (rare) with a custom extract and load process. We had over 3,500 tables and identified about 100 that worked better done as SQLLoader rather than GG. When I say better I mean with data handling and speed of migration. We created different groups of processing each group having a different method.
Once we have an overall hybrid scheme that works, we tune, mainly by splitting that task into parallel processes, both the export and import side.
All my migrations have been big projects where we have shifted from one Oracle system/server to another, always with the target being a newer version of OS and Oracle.
So, I would imagine that migration between non-Oracle and Oracle will through up even more challenges, and probably not as trivial as imply clicking a few buttons in SQL*Developer.
You may find the expected content from the SQL developer documentation at the Oracle website.
There are migration information available for all Microsoft Access users, MySQL users, Microsoft SQL Server and Sybase Adaptive Server users.
You can also download the tutorial in forms of PDF (best for offline viewing and printing), ePub (best for most mobile devices) and Mobi (best for Amazon Kindle devices).
Recently, I have successfully migrated the MySQL database to Oracle database. Below are detail steps:
Operating System: Desktop Ubuntu local and Desktop Ubuntu on amazon aws
Please Note: Here I am using aws desktop ubuntu server because my mysql
database was pretty big. In my case there were 800 tables, 200 views,
procedures, triggers, and functions. The total size of the database was almost
20GB. In case of small database I would recommend to use local ubuntu server.
Tools Used: SQL Developer, VNCServer, Remote Desktop Client, JAVA 8, Third Party MySql JDBC Driver
1. Setup ec2 ubuntu desktop server : https://www.youtube.com/watch?v=ljvgwmJCUjw
2. Install SQL Developer on #1
Download the SQL Developer package from this link :
http://www.oracle.com/technetwork/developer-tools/sql-developer/downloads/index.html
Accept the license agreement and download "Other Platforms" for ubuntu.
Install the SQL developer package as the following.
sudo apt-get install sqldeveloper-package debhelper openjdk-7-jdk
openjdk-7-jre icedtea-7-plugin
Now all that you need to do is to run the command (you might have a
different version)
make-sqldeveloper-package sqldeveloper-4.1.3.20.78-no-jre.zip
This will generate a debian package that you can use to install SQL developer.
Now install the resulting .deb package using the command (Your deb
might have a different version too)
sudo dpkg -i sqldeveloper_4.1.3.20.78+0.2.4-1_all.deb
In my case, I have used java 8.
3. Once you have done with your SQL developer installation on your newly created ec2 instance with VNCServer then all you need to do is to connect to that ec2 instance with the Remote Desktop Client by default available in your ubuntu local machine.
Use IP:1 with user/pass setup for VNCServer in #1
You can see the remote ec2 ubuntu desktop server. You have to grab the keyboard inputs from the Remote Desktop tool if you want to tab inside the remote server.
Once you get connected with the remote client, open SQL Developer from the terminal or from the explorer.
sqldeveloper
Follow the migration steps provided by Oracle corporation:
http://www.oracle.com/technetwork/database/migration/mysql-093223.html
Please Note: While following the migration steps provided by the
oracle they will ask for the destination database connection i.e. oracle
database connection. This is not the database where your MySQL
database will be migrated. Instead, this database connection will
be used for the migration process. Your database connection user
must have user and database create privileges. Once your connection
have user create privilege, then migration process automatically create
the corresponding database user in Oracle database[if you have mysql_test_db in MySQL
database, same mysql_test_db will be created in Oracle db too].
I recently used sqline's tool http://www.sqlines.com/cmd to convert a dump from mysql in the form of an .sql script to an (almost) Oracle-compatible sql script.
sqlines31113\sqlines.exe -s=mysql -t=oracle "-in=$infile"
I just had to (semi-manually) fix some things in the output and then I could run it on my oracle database.
I am making a project in C and I need database access. How would you connect to and access a database in the C language? I am using MySQL currently.
There are many solutions, depending on which database you are using and which OS you are using. One solution that will provide broad access to an array of combinations would be ODBC. You would connect to the database with a function like SQLConnect and use the other API functions to do your queries.
The links are windows specific, but you should be able to find analogs for whatever OS you will be using on your client side.
Depending on why you actually need to use a database (you didn't say) you could start using SQLite to develop your application.
Once you have it working and you have decided on which server you want to use (MySQL, MS SQL Server, Oracle, etc.) you can then read the documentation on creating a connection specific to that database server.
What's the best way to synchronize few tables of mysql server with postgreSQL server?
Currently people are executing scripts, which takes much time, is there any fast solution available from which we can map the tables and columns to synchronize the db server.
You could expose the data from one and consume it with the other. Something like a web service, linked server, open data framework, ODBC driver, etc. Postgres has a nice ODBC driver that works pretty well.