MVCC JDBC option is unsupported in 1.4.200

[MikielAgutu]

Using version 1.4.200:

• Open H2 Console in browser
• Connect using JDBC url jdbc:h2:mem:some_db;MVCC=TRUE;
• Error: Unsupported connection setting "MVCC" [90113-200] 90113/90113

This works in 1.4.199. Is it intentionally deprecated?

[katzyn]

Please, read the release notes:
https://github.com/h2database/h2database/releases/tag/version-1.4.200

This setting has no effect in 1.4.198 and 1.4.199 and it was entirely removed in 1.4.200 to avoid accidental misuse.
https://github.com/h2database/h2database/releases/tag/version-1.4.198

[jameskleeh]

What versioning scheme is this library using if its OK to have a breaking change in a patch version?

[katzyn]

H2 isn't a library, it's a database system.

Releases of H2 are simply numbered sequentially. 1.4.197, 1.4.198, and 1.4.200 are big releases with many changes; you need to read the release notes first.

[jameskleeh]

@katzyn So then what would 1.5 represent? 2.0?

[katzyn]

Who knows? 1.4, for example, has an entirely new storage engine.

You should not try to guess how versions of one or another software are numbered. There are too many different practices.

[jameskleeh]

@katzyn That is my point exactly. I was inquiring what the practice is here and it seems like there really isn't one. That is unfortunate.

[grandinj]

Yeah we largely inherited this project along with its versioning scheme, and it predates the whole "semantic versioning" thing, not that that would make much difference with a database engine, where pretty much any change can break someone's app