The chunk size used in sstable compression can be set when creating a
table, using the "chunk_length_in_kb" parameter. It can be any power-of-two
multiple of 1KB. Very large compression chunks are not useful - they
offer diminishing returns on compression ratio, and require very large
memory buffers and reading a very large amount of disk data just to
read a small row. In fact, small chunks are recommended - Scylla
defaults to 4 KB chunks, and Cassandra lowered their default from 64 KB
(in Cassandra 3) to 16 KB (in Cassandra 4).
Therefore, allowing arbitrarily large chunk sizes is just asking for
trouble. Today, a user can ask for a 1 GB chunk size, and crash or hang
Scylla when it runs out of memory. So in this patch we add a hard limit
of 128 KB for the chunk size - anything larger is refused.
Fixes#9933
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Closes#14267
and add docs/dev/timestamp-conflict-resolution.md
to document the details of the conflict resolution algorithm.
Refs scylladb/scylladb#14063
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
This commit adds a table (with 1 row) explaining Scylla-specific
materialized view options - which now consists just of
synchronous_updates.
Tested manually by running `make preview` from docs/ directory.
Closes#11150
We used to allow IS NOT NULL restrictions on columns
that were not part of the materialized view's primary key.
It runs out that such restrictions are silently ignored (see #10365),
so we no longer allow such restrictions.
Update the documentation to reflect that change.
Also there was a mistake in the documentation.
It said that restrictions are allowed on all columns
of the base table's primary key, but they are actually
allowed on all columns of the view table's primary key,
not the base tables.
This change also fixes that mistake.
Signed-off-by: Jan Ciolek <jan.ciolek@scylladb.com>
Fixes https://github.com/scylladb/scylladb/issues/13578
Now that the documentation is versioned, we can remove
the .. versionadded:: and .. versionchanged:: information
(especially that the latter is hard to maintain and now
outdated), as well as the outdated information about
experimental features in very old releases.
This commit removes that information and nothing else.
Closes#13680
The tombstone_gc was documented as experimental in version 5.0.
It is no longer experimental in version 5.2.
This commit updates the information about the option.
Closes#13469
Even after last fixups, the documentation still had some issues with
compilation instructions in particular. I also ran a spelling and
grammar check on the text, and fixed issues found by it.
Closes#13206
This patch fixes 2 small issues with the Wasm UDF documentation that
recently got uploaded:
1. a link was unnecessarily wrapped in angle brackets
2. a link did not redirect to the correct page due to a missing ":doc:" tag
Closes#13193
Until now, the instructions on generating wasm files and using them
for Scylla UDFs were stored in docs/dev, so they were not visible
on the docs website. Now that the Rust helper library for UDFs
is ready, and we're inviting users to try it out, we should also
make the rest of the Wasm UDF documentation readily available
for the users.
Closes#13139
Related: https://github.com/scylladb/scylladb/issues/13119
This commit removes the pages that describe Enterprise only features
from the Open Source documentation:
- Encryption at Rest
- Workload Prioritization
- LDAP Authorization
- LDAP Authentication
- Audit
In addition, it removes most of the information about Incremental
Compaction Strategy (ICS), which is replaced with links to the
Enterprise documentation.
The changes above required additional updates introduced with this
commit:
- The links to Enterprise-only features are replaced with the
corresponding links in the Enterprise documentation.
- The redirections are added for the removed pages to be redirected to
the corresponding pages in the Enterprise documentation.
This commit must be reverted in the scylla-enterprise repository to
avoid deleting the Enterprise-only content from the Enterprise docs.
Closes#13123
Previously, we rejected map subscripts that are NULL, as well as
LIKE patterns that are NULL. General SQL expression evaluation
allows NULL everywhere, and doesn't raise errors - an expression
involving NULL generally yields NULL. Change the behavior to
follow that. Since the new behavior was previously disallowed,
no one should have been relying on it and there is no compatibility
problem.
Update the tests and note it as a CQL extension.
Our handling of NULLs in expressions is different from Cassandra's,
and more uniform. For example, the filter "WHERE x = NULL" is an
error in Cassandra, but supported in Scylla. Let's explain how and why.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Closes#12494
This PR is V2 of the[ PR created by @psarna.](https://github.com/scylladb/scylladb/pull/11560).
I have:
- copied the content.
- applied the suggestions left by @nyh.
- made minor improvements, such as replacing "Scylla" with "ScyllaDB", fixing punctuation, and fixing the RST syntax.
Fixes https://github.com/scylladb/scylladb/issues/11378Closes#11984
* github.com:scylladb/scylladb:
doc: label user-defined functions as Experimental
doc: restore the note for the Count function (removed by mistatke)
doc: document user defined functions (UDFs)
List the queries that support the TIMEOUT parameter.
Mention the newly added support for TRUNCATE
USING TIMEOUT.
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
Fix https://github.com/scylladb/scylladb/issues/11373
- Updated the information on the "Counting all rows in a table is slow" page.
- Added COUNT to the list of selectors of the SELECT statement (somehow it was missing).
- Added the note to the description of the COUNT() function with a link to the KB page for troubleshooting if necessary. This will allow the users to easily find the KB page.
Closes#11417
* github.com:scylladb/scylladb:
doc: add a comment to remove the note in version 5.1
doc: update the information on the Countng all rows page and add the recommendation to upgrade ScyllaDB
doc: add a note to the description of COUNT with a reference to the KB article
doc: add COUNT to the list of acceptable selectors of the SELECT statement
Fix https://github.com/scylladb/scylla-doc-issues/issues/816
Fix https://github.com/scylladb/scylla-docs/issues/1613
This PR fixes the CQL version in the Interfaces page, so that it is the same as in other places across the docs and in sync with the version reported by the ScyllaDB (see https://github.com/scylladb/scylla-doc-issues/issues/816#issuecomment-1173878487).
To make sure the same CQL version is used across the docs, we should use the `|cql-version| `variable rather than hardcode the version number on several pages.
The variable is specified in the conf.py file:
```
rst_prolog = """
.. |cql-version| replace:: 3.3.1
"""
```
Closes#11320
* github.com:scylladb/scylladb:
doc: add the Cassandra version on which the tools are based
doc: fix the version number
doc: update the Enterprise version where the ME format was introduced
doc: add the ME format to the Cassandar Compatibility page
doc: replace Scylla with ScyllaDB
doc: rewrite the Interfaces table to the new format to include more information about CQL support
doc: remove the CQL version from pages other than Cassandra compatibility
doc: fix the CQL version in the Interfaces table
It was recently decided that the database should be referred to as
"ScyllaDB", not "Scylla". This patch changes existing references
in docs/cql/cql-extensions.md.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
It was pointed out to me that our description of the synchronous_updates
materialized-view option does not make it clear enough what is the
default setting, or why a user might want to use this option.
This patch changes the description to (I hope) better address these
issues.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
