Suggestion: include Doltgres brand in version string

[emarsden]

Currently, the return value of version() is something like PostgreSQL 15.5. It would be useful to include Doltgres in the string returned by function version(), and possibly in a parameter string sent on PostgreSQL connection startup such as database=doltgres.

Rationale: clients connecting using the PostgreSQL wire protocol may need to change their behaviour depending on the PostgreSQL variant. For example, Doltgres doesn't currently parse timezones such as UTC-01:00.

Examples for other PostgreSQL variants:

• CockroachDB has CockroachDB CCL v26.1.1 (x86_64-pc-linux-gnu, built 2026/03/04 12:08:22, go1.25.5)
• YDB has backend parameter server_version=14.5 (ydb stable-23-4)
• Yugabyte has PostgreSQL 15.12-YB-2025.2.1.0-b0 on x86_64-pc-linux-gnu, compiled by clang version 19.1.0 (https://github.com/yugabyte/llvm-project.git a2a6b655e14e7fa1fcf1011a6cb29cb8575249c0), 64-bit
• Materialize has PostgreSQL 9.5 on x86_64-unknown-linux-gnu (Materialize 26.16.0), startup parameter database=materialize
• Risingwave has PostgreSQL 13.14.0-RisingWave-2.8.0 (bb13a21d5d5982e947887ce794b4bff99f109fc7)

[Hydrocharged]

Our goal with Doltgres is that clients will specifically not need to change their behavior. To that end, we plan to ensure as complete compatibility as possible with Postgres, and therefore we should return the same string as our supported Postgres version.

The difference mentioned (the UTC-01:00 issue) was a bug on our part, and has been fixed. Please continue to report any more issues or discrepancies that you may find! We're hard at work to make sure that we support what you, our users, need.