Replication from MySQL to SQL Server

Question

I have a system in which data is written constantly. It works on MySQL, I also have a second system that runs on SQL Server and uses some parameters from the first base.

Question: how is it possible (is this even possible) to constantly transfer values from one base (MySQL) to another (SQL Server)? The option to switch to one base is not an option. As I understand it, it will be necessary to write a program for example in Delphi which will transfer values from the other database to another.

Answer 1

You have a number of options.

SQL Server can access another database using ODBC, so you could setup SQL server to obtain the information it needs directly from tables that are held in MySQL.

MySQL supports replication using log files, so you could configure MySQL replication (which does not have to be on all tables) to write relevant transactions to a log file. You would then need to process that log file (which you could do in (almost) real time as the standard MySQL replication does) to identify what needs to be written to the MS SQL Server. Typically this would produce a set of statements to be run against the MS SQL server. You have any number of languages you could use to process the log file and issue the updates.

You could have a scheduled task that reads the required parameters from MySQL and posts it to MS SQL, but this would leave a period of time where the two may not be in sync. Given that you may have an issue with parsing log files and posting the updates you may still want to implement this as a fall back if you are processing log files.

If the SQL Server and the MySQL server are on the same network the external tables method is likely to be simplest and lowest maintenance, but depending on the amount of data involved you may find the overhead of the external connection and queries could affect the overall performace of the queries made against the MS SQL Server.