Hello,
A diff tool that would generate create, drop, alter, etc. commands from the differences between 2 specified schemes would be very useful. The diff could even manage data, so there would be insert, delete update command outputs, although I think the schema diff management is much more important and necessary.
Today, all modern applications are version-tracked, including the sql scheme. Now the schema changes must be handled twice: on the one hand, the schema must be modified, and on the other hand, the schema modification commands must also be written for the upgrade process. A good diff tool would allow only the schema to be modified.
Such a tool already exists because the community needed it, e.g. apgdiff. I think the problem with this is that the concept isn't even good. I think this tool should be part of postgresql, because postgresql always knows what the 100% sql syntax is current, an external program, for example apgdiff can only follow changes afterwards, generating continuous problems. Not to mention that an external application can stop, e.g. apgdiff is also no longer actively developed, so users who built on a diff tool are now in trouble.
Furthermore, it is the least amount of work to do this on the postgresql development side, you have the expertise, the sql language processor, etc.
What is your opinion on this?
Regards,
Neszt Tibor