Greenplum vs Postgres-XL

Question

I was looking at those two massively parallel databases: Postgres-XL and Greenplum .

Problem is, I do not know how to choose between them, because they both seems the same: both are open sourced, based on PostgreSQL, both use MPP, both have similiar APIs. Only difference I found is that Greenplum is written in Erlang and Postgres-XL in C.

Exists there some use case, in which one si better than the other?

Thank you

Answer 1

There are a lot of details to go into on the differences, way too many for a single post to cover, but the biggest stand out one to me was that PostgresXL does NOT have any fail over. If you lose one node you have lost the entire database.

Their only work around for this is to have a mirrored instances for each node, ( ie You need double the number of nodes, so double the admin headache and cost ) and even then it still can't fail over. You will have to take the entire database off line, and remove the failed node from the config and restart it. This was a HUGE deal breaker for me.

Answer 2

Why you should consider Postgres XL or Greenplum?

Version:

Postgres XL uses 9.5 or 9.6 version that is mainstream following the community PostgreSQL DB closely. When the Postgres community released Postgres 10, Postgres-XL 10 beta/pre-prod version is also released.

Whereas Greenplum currently has Postgres 8+ versions, in its latest release.

UseCases:

Greenplum started in the market as a commercial product with Pivotal, that was acquired by EMC, giving itself a market with EMC storage and Dell servers, hence it is widely used and has a good market presence and later Greenplum becoming an Open-Source product, which freed itself from vendor lock-in and also gave it more customers and users.

Whereas Postgres XL is in the market through the backing of postgres community and companies that support it, therefore you would see steady growth in the usage of Postgres-XL as well.

Sites: https://www.postgres-xl.org/ , https://greenplum.org/