Apache Impala VS ibis

> whether this would really work out in most workloads

> just because it keeps the cache-lines hotter and less likely to be evicted.

Okay, so keeping cache for a bloom filter problem is real - but the real force evicting memory out of the cache line is the next row-group you read + all the other stuff you have to do when you implement this in a database product.

So the two things I work with, Apache Hive and Apache Impala switched to a blocked bloom filter at different points in time.

Hive BloomKFilter - https://github.com/apache/hive/blob/master/storage-api/src/j...

Impala/Kudu one - https://github.com/apache/impala/blob/master/be/src/kudu/uti...

The C++ one also has an AVX specialization, while the Java one relies on the JVM to do it (not always) - https://github.com/apache/impala/blob/master/be/src/kudu/uti...

We ran a lot of trivial benchmarks and several benchmarks where the shuffle-join (not sort-merge, this is just a partitioned hash join) generates a bloom filter (a semijoin) before sending rows out and the 1-cache line version won out when the bloom filter went slightly over the 1 Million + 5% rate [1].

The regular bloom filter went from (38ns -> 108ns for 1k -> 1m items), while the BloomK stuck at (27ns) despite making room for a million times more items in the bloom. The bloom-1 (which is the 64bit version) underperformed on accuracy (was ~2x faster at 16ns per op, but worse at filtering out items).

[1] - https://github.com/prasanthj/bloomfilter/tree/master/benchma...

I really don't understand the appeal of dbt vs a proper programming language. The templating approach leads to massive spaghetti. I look forward to trying out something like Ibis [0]

0: https://ibis-project.org/

ibis – portable Python dataframe library

The main benefit is that you get a Python (or R, Julia or Rust) interpreter. So you can evaluate code. A good example of the value of this is the Ibis docs which use Quarto: https://ibis-project.org/

Ive found polars quite intuitive, though for python, I lean more towards [ibis](https://ibis-project.org/). The interface is nearly identical, but ibis has the benefit if building sql queries before pulling any actual data (like dbplyr) — whereas polars requires the data to be in-memory (at least for rdb’s, though correct me if Im wrong)

this to me seems like a good argument for only using ibis, but Im happy to be convinced otherwise

Please add Ibis Birdbrain https://ibis-project.github.io/ibis-birdbrain/ to the list. Birdbrain is an AI-powered data bot, built on Ibis and Marvin, supporting more than 18 database backends.

See https://github.com/ibis-project/ibis and https://ibis-project.org for more details.