Viewing profile — bluestreak

In certain situations, crossing the JNI boundary can be advantageous. When data resides in "native" memory, outside the Java heap, the coordination of concurrent execution logic ca…

this is THE number one question being asked about QuestDB :) There is a thread that might help https://news.ycombinator.com/item?id=37557880

One of our distribution channels is Maven Central where we ship Java 11 compatible library. Embedded users preclude us from leveraging latest Java features.

Java tooling was excellent back when QuestDB was started and still is excellent today compared to C++.

great, we are on the same page! `fallocate()` (or posix one) is called on large swades of file. 16MB default. Not too often to hurt performance. I wonder if zeroing the file with `…

> On x86, and I think every architecture, when you write to a memory mapping that is not already backed by a writable page, the kernel is notified that user code is trying to write…

It is not always read-write-modify. There is no evidence of this pattern in Ubuntu when there is no memory pressure. Merge occurs when block is partially updated after kenel had lo…

I am excited for what Memory API brings. The biggest pain with native memory management for us are "struct" or lack of those. Extremely bug prone memory arithmetic I personally am …

I couldn't agree more. I don't think compiler vectorization is that useful even for columnar (!) database we're building. The specialized JIT doesn't even use AVX512 because too mu…

Thank you for sharing the post! I’m vlad, cto of questdb - we went all the way trying to optimize CSV ingestion with io_uring, and ended up benchmarking against some OLAP peers in …

The query Clickhouse picked on does not actually leverage time order. Perhaps clickhouse vendors on this thread can comment on relevance of the date partitioning for this query. My…

"fair" means that we comparing apples to apples. Ad-hoc, unindexed predicate, compiled by QuestDB into AVX2 assembly (using AsmJIT) vs same predicate complied by Clickhouse (I'm as…

Full disclosure: I am CTO of QuestDB and I took part in JIT implementation. The quote above is not mine, it was written by Clickhouse staff. "utilizes its full indexing strategy" s…

I am in fact very proud of my team, who worked very hard on both implementation and the article. It is disappointing to read unfounded insults where we made every effort to be fair…