Mark Papadakis

Trinity now supports the recently(yesterday) released Streaming VByte encoding scheme by Daniel Lemire. Read [the blog post](https://lemire.me/blog/2017/09/27/stream-vbyte-breaking-new-speed-records-for-integer-compression/) for an introduction. When selected (see `lucene_codec.h`), it generally results in at least...

@ddorian you can choose between PFOR, Streaming VByte and Masked VByte, see lucene_codec.h for how to select the encoding scheme. In practice, most systems nowadays (well, CPUs) support SSE 4.0+...

I have experienced the issue multiple times in the past which effectively prevents us from using this map implementation. I thought I filed an issue about this but looks like...

I can reproduce it, but it is practically impossible to share the code (its for out embeddable columnar store thing, that's not OSS). Certain SQL queries would cause this --...

For what it's worth, in cases where it fails, we don't erase any KVs. It's all insertions. It occurs when inserting elements.

Also, we experimented with various many different hash maps implementations. None of them failed so it's perhaps safe to suggest that the issue's specific to this implementation.

@gabrieltanase42: I just tried [this commit](https://github.com/Tessil/robin-map/tree/4abcc978b94478febddd76594a2c1ecb7d5fc5f3) and still fails.

IIRC it always failed in MT programs for us and it's always about maps protected with either an std::mutex or an std::shared_mutex. As I mentioned in a previous comment, no...

@Tessil I just ran again this service/program that fails consistently (as described in other comments). I switched from a CitHash variant to xxHash, and even tried a differ GP, but...

There is a class like that, in heavy use [here](http://phaistosnetworks.gr/), but it hasn't been merged into the client, because we 'll eventually provide a Kafka-streams like abstraction that can also...