MongoDB queries don’t always return all matching documents

I've just migrated one project from mongo to postgresql and i advise you to do the same. It was my mistake to use mongo, after I've found memory leak in cursors first day I've used the db which I've reported and they fixed it. It was 2015.. If you have a lot of relations in your data don't use mongo, it's just hype. You will end up with collections without relations and then do joins in your code instead of having db do it for you.

Re: MongoDB queries don’t always return all matching documents

#5

Post by ubercore » Tue, Jun 07, 2016, 9:08 PM UTC

bioinformatics wrote: post #3

doubleorseven wrote: post #2

Mongo, in one word: sucks. Couchbase, does not.

I use RethinkDB in most of my production things. I recommend it.

Agreed, I've had nothing but positive experiences with it.

Re: MongoDB queries don’t always return all matching documents

#6

Post by jitix » Tue, Jun 07, 2016, 9:08 PM UTC

What storage engine are you using? I wonder if the same issue comes in wiredtiger MVCC engine.

Re: MongoDB queries don’t always return all matching documents

#7

Post by Animats » Tue, Jun 07, 2016, 9:10 PM UTC

Not when they're changing rapidly, anyway. Well, that's relaxed consistency for you.

Does this guy have so many containers running that the status info can't be kept in RAM? I have a status table in MySQL that's kept by the MEMORY engine; it's thus in RAM. It doesn't have to survive reboots.

Re: MongoDB queries don’t always return all matching documents

#8

Post by lossolo » Tue, Jun 07, 2016, 9:13 PM UTC

jitix wrote: post #6

What storage engine are you using? I wonder if the same issue comes in wiredtiger MVCC engine.

He wrote in comments that this issue is in mmap and in wiredtiger.

Re: MongoDB queries don’t always return all matching documents

#9

Post by Joeboy » Tue, Jun 07, 2016, 9:18 PM UTC

lossolo wrote: post #4

I've just migrated one project from mongo to postgresql and i advise you to do the same. It was my mistake to use mongo, after I've found memory leak in cursors first day I've used the db which I've reported and they fixed it. It was 2015.. If you have a lot of relations in your data don't use mongo, it's just hype. You will end up with collections without relations and then do joins in your code instead of having db…

> don't use mongo, it's just hype

I'm kind of curious as to where this hype is. I've almost never heard anybody say anything positive about mongodb. All I ever see is people saying it's terrible / hilarious for various reasons.

Re: MongoDB queries don’t always return all matching documents

#10

Post by api » Tue, Jun 07, 2016, 9:24 PM UTC

Joeboy wrote: post #9

lossolo wrote: post #4

I've just migrated one project from mongo to postgresql and i advise you to do the same. It was my mistake to use mongo, after I've found memory leak in cursors first day I've used the db which I've reported and they fixed it. It was 2015.. If you have a lot of relations in your data don't use mongo, it's just hype. You will end up with collections without relations and then do joins in your code instead of having db…

> don't use mongo, it's just hype I'm kind of curious as to where this hype is. I've almost never heard anybody say anything positive about mongodb. All I ever see is people saying it's terrible / hilarious for various reasons.

It's massively successful in the entry level web coding world due to a combination of good marketing and the belief that it gives you unlimited scale 'for free' and everything 'just works.'

Not saying those are impossible goals but so far no database has managed to deliver that. Building a large-scale endlessly-scalable database is still very hard and very detailed and easy to screw up.