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This test reproduces issue #10365: It shows that although "IS NOT NULL" is
not allowed in regular SELECT filters, in a materialized view it is allowed,
even for non-key columns - but then outright ignored and does not actually
filter out anything - a fact which already surprised several users.

The test also fails on Cassandra - it also wrongly allows IS NOT NULL
on the non-key columns but then ignores this in the filter. So the test
is marked with both xfail (known to fail on Scylla) and cassandra_bug
(fails on Cassandra because of what we consider to be a Cassandra bug).

Refs #10365
Refs #11606

Signed-off-by: Nadav Har'El <>

Closes #11615


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What is Scylla?

Scylla is the real-time big data database that is API-compatible with Apache Cassandra and Amazon DynamoDB. Scylla embraces a shared-nothing approach that increases throughput and storage capacity to realize order-of-magnitude performance improvements and reduce hardware costs.

For more information, please see the ScyllaDB web site.

Build Prerequisites

Scylla is fairly fussy about its build environment, requiring very recent versions of the C++20 compiler and of many libraries to build. The document includes detailed information on building and developing Scylla, but to get Scylla building quickly on (almost) any build machine, Scylla offers a frozen toolchain, This is a pre-configured Docker image which includes recent versions of all the required compilers, libraries and build tools. Using the frozen toolchain allows you to avoid changing anything in your build machine to meet Scylla's requirements - you just need to meet the frozen toolchain's prerequisites (mostly, Docker or Podman being available).

Building Scylla

Building Scylla with the frozen toolchain dbuild is as easy as:

$ git submodule update --init --force --recursive
$ ./tools/toolchain/dbuild ./
$ ./tools/toolchain/dbuild ninja build/release/scylla

For further information, please see:

Running Scylla

To start Scylla server, run:

$ ./tools/toolchain/dbuild ./build/release/scylla --workdir tmp --smp 1 --developer-mode 1

This will start a Scylla node with one CPU core allocated to it and data files stored in the tmp directory. The --developer-mode is needed to disable the various checks Scylla performs at startup to ensure the machine is configured for maximum performance (not relevant on development workstations). Please note that you need to run Scylla with dbuild if you built it with the frozen toolchain.

For more run options, run:

$ ./tools/toolchain/dbuild ./build/release/scylla --help


See manual.

Scylla APIs and compatibility

By default, Scylla is compatible with Apache Cassandra and its APIs - CQL and Thrift. There is also support for the API of Amazon DynamoDB™, which needs to be enabled and configured in order to be used. For more information on how to enable the DynamoDB™ API in Scylla, and the current compatibility of this feature as well as Scylla-specific extensions, see Alternator and Getting started with Alternator.


Documentation can be found here. Seastar documentation can be found here. User documentation can be found here.


Training material and online courses can be found at Scylla University. The courses are free, self-paced and include hands-on examples. They cover a variety of topics including Scylla data modeling, administration, architecture, basic NoSQL concepts, using drivers for application development, Scylla setup, failover, compactions, multi-datacenters and how Scylla integrates with third-party applications.

Contributing to Scylla

If you want to report a bug or submit a pull request or a patch, please read the contribution guidelines.

If you are a developer working on Scylla, please read the developer guidelines.


  • The users mailing list and Slack channel are for users to discuss configuration, management, and operations of the ScyllaDB open source.
  • The developers mailing list is for developers and people interested in following the development of ScyllaDB to discuss technical topics.