The secondary index mechanism is currently used to determine the target column.
This mechanism works incorrectly for vector indexes with filtering because
it returns the last specified column as the target (vectors) column.
However, the syntax for a vector index requires the first column to be the target:
```
CREATE CUSTOM INDEX ON t(vectors, users) USING 'vector_index';
```
This discrepancy eventually leads to the following exception when performing an
ANN search on a vector index with filtering columns:
````
ANN ordering by vector requires the column to be indexed using 'vector_index'
````
This commit fixes the issue by introducing dedicated logic for vector indexes
to correctly identify the target(vectors) column.
Fixes: SCYLLADB-635
Closesscylladb/scylladb#28740
3f7ee3ce5d introduced system.batchlog_v2, with a schema designed to speed up batchlog replays and make post-replay cleanups much more effective.
It did not introduce a cluster feature for the new table, because it is node local table, so the cluster can switch to the new table gradually, one node at a time.
However, https://github.com/scylladb/scylladb/issues/27886 showed that the switching causes timeouts during upgrades, in mixed clusters. Furthermore, switching to the new table unconditionally on upgrades nodes, means that on rollback, the batches saved into the v2 table are lost.
This PR introduces re-introduces v1 (`system.batchlog`) support and guards the use of the v2 table with a cluster feature, so mixed clusters keep using v1 and thus be rollback-compatible.
The re-introduced v1 support doesn't support post-replay cleanups for simplicity. The cleanup in v1 was never particularly effective anyway and we ended up disabling it for heavy batchlog users, so I don't think the lack of support for cleanup is a problem.
Fixes: https://github.com/scylladb/scylladb/issues/27886
Needs backport to 2026.1, to fix upgrades for clusters using batches
Closesscylladb/scylladb#28736
* github.com:scylladb/scylladb:
test/boost/batchlog_manager_test: add tests for v1 batchlog
test/boost/batchlog_manager_test: make prepare_batches() work with both v1 and v2
test/boost/batchlog_manager_test: fix indentation
test/boost/batchlog_manager_test: extract prepare_batches() method
test/lib/cql_assertions: is_rows(): add dump parameter
tools/scylla-sstable: extract query result printers
tools/scylla-sstable: add std::ostream& arg to query result printers
repair/row_level: repair_flush_hints_batchlog_handler(): add all_replayed to finish log
db/batchlog_manager: re-add v1 support
db/batchlog_manager: return all_replayed from process_batch()
db/batchlog_manager: process_bath() fix indentation
db/batchlog_manager: make batch() a standalone function
db/batchlog_manager: make structs stats public
db/batchlog_manager: allocate limiter on the stack
db/batchlog_manager: add feature_service dependency
gms/feature_service: add batchlog_v2 feature
This series implements a new per-row TTL feature for CQL. The per-row TTL feature was requested in issue #13000. It is a feature that does not exist in Cassandra, and was inspired by DynamoDB's TTL feature - and under the hood uses the same implementation that we used in Alternator to implement this DynamoDB feature.
The new per-row TTL feature is completely separate from CQL's existing per-write (and per-cell) TTL, and both will be available to users.
In the per-row TTL feature, one column in the table is designated as the "TTL" column, and its value for a row is the expiration time for that row. The TTL column can be designated at table creation time, e.g.:
```cql
CREATE TABLE tab (
id int PRIMARY KEY,
t text,
expiration timestamp TTL
);
```
Or after the table already exists with:
```cql
ALTER TABLE tab TTL expiration
```
Expiration can also be disabled, with:
```cql
ALTER TABLE tab TTL NULL
```
The new per-row TTL feature has two features that users have been asking for:
1. A user can change the value of just the TTL column - without rewriting the entire row - to change the expiration time of the entire row.
2. When an expired row is finally deleted, a CDC event about this deletion appears in the CDC log (if CDC is enabled), including - if a preimage is enabled - the content of the deleted row.
To achieve the second goal (CDC events), a row is not guaranteed to disappear at exactly its expiration time (as CQL's original TTL feature guarantees). Rather, the row is deleted some time later, depending on `alternator_ttl_period_in_seconds`; Until the actual deletion, the row is still readable (and even writable). But we are guaranteed that when the row is finally deleted, the CDC event will come too.
The implementation uses the same background thread used by Alternator to periodically scan for expired items and delete them.
The expiration thread keeps the same metrics as it did for Alternator:
* `scylla_expiration_scan_passes`
* `scylla_expiration_scan_table`
* `scylla_expiration_items_deleted`
* `scylla_expiration_secondary_ranges_scanned`
The series begins with a few small preparation patches, followed by the main part of the feature (which isn't big, since we are just enabling the pre-existing Alternator expiration machinary for CQL) and finally 30 tests (single-node and multi-node tests) and documentation.
This series is a new feature, so traditionally would not be backported. However, I wouldn't be surprised if we will be requested to backport it so that customers will not need to wait for a new major release.
Fixes#13000Closesscylladb/scylladb#28320
* github.com:scylladb/scylladb:
test/cqlpy: verify that a column can't be both STATIC and PRIMARY KEY
docs/cql: document the new CQL per-row TTL feature
test/cluster: tests for the new CQL per-row TTL feature
test/cqlpy: tests for the new CQL per-row TTL feature
test: set low alternator_ttl_period_in_seconds in CQL tests
cql ttl: fix ALTER TABLE to disable TTL if column is dropped
cql ttl: add setting/unsetting of TTL column to ALTER TABLE
cql ttl: add TTL column support to CREATE TABLE and DESC TABLE
ttl: add CQL support to Alternator's TTL expiration service
alternator ttl: move TTL_TAG_KEY to a header file
alternator ttl: remove unnecessary check of feature flag
cql: add "cql_row_ttl" cluster feature
alternator: fix error message if UpdateTimeToLive is not supported
Switch vector dimension handling to fixed-width `uint32_t` type,
update parsing/validation, and add boundary tests.
The dimension is parsed as `unsigned long` at first which is guaranteed
to be **at least** 32-bit long, which is safe to downcast to `uint32_t`.
Move `MAX_VECTOR_DIMENSION` from `cql3_type::raw_vector` to `cql3_type`
to ensure public visibility for checks outside the class.
Add tests to verify the type boundaries.
Fixes: https://scylladb.atlassian.net/browse/SCYLLADB-223
Signed-off-by: Yaniv Kaul <yaniv.kaul@scylladb.com>
Co-authored-by: Dawid Pawlik <dawid.pawlik@scylladb.com>
Closesscylladb/scylladb#28762
If "ALTER TABLE tab DROP x" is done to delete column x, and column x was
the designated TTL column, then the per-row TTL feature should be disabled
on this table.
If we don't do this, the expiration scanner will continue to scan the
table trying to read the dropped column - which will be wasteful or
worse.
A test for this case is also included in test/cqlpy/test_ttl_row.py
in a later patch.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
The previous patch added the ability in CREATE TABLE to designate one
of the regular columns as a "TTL column", to be used by the per-row TTL
feature (Refs #13000). In this patch we add to ALTER TABLE the ability
to enable per-row TTL on an existing table with a given column as the
TTL column:
ALTER TABLE tab TTL colname
and also the ability to disable per-row TTL with
ALTER TABLE tab TTL NULL
as in CREATE TABLE, the designated TTL column must be a regular column
(it can't be a primary key column or a static column), and must have
the types timestamp, bigint or int.
You can't enable per-row TTL if already enabled, or disable it if
already disabled. To change the TTL column on an existing table,
you must first disable TTL, and then re-enable it with the new column.
A large collection of functional tests (in test/cqlpy), for every detail
of this patch, will come in a later patch in this series.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
This patch enables the per-row TTL feature in CQL (Refs #13000).
This patch allows the user to create a new table with one of its columns
designated as the TTL column with a syntax like:
CREATE TABLE tab (
id int PRIMARY KEY,
t text,
expiration timestamp TTL
);
The column marked "TTL" must have the "timestamp", "bigint" or "int"
types (the choice of these types was explained in the previous patch),
and there can only be one such column. We decided not to allow a column
to be both a primary key column and a TTL column - although it would
have worked (it's supported in Alternator), I considered this non-useful
and confusing, and decided not to allow it in CQL. A TTL column also
can't be a static column.
We save the information of which column is the TTL column in a tag which
is read by the "expiration service" - originally a part of Alternator's
TTL implementation. After the previous patch, the expiration service is
running and knows how to understand CQL tables, so the CQL per-row TTL
feature will start to work.
This patch also implements DESC TABLE, printing the word "TTL" in the
right place of the output.
This patch doesn't yet implement ALTER TABLE that should allow enabling
or disabling the TTL column setting on an existing table - we'll do that
in the next patch.
A large collection of functional tests (in test/cqlpy), for every detail
of this feature will be added in a later patch.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
The ANN vector queries with all-zero vectors are allowed even on vector indexes with similarity function set to cosine.
When enabling the rescoring option, those queries would fail as the rescoring calls `similarity_cosine` function underneath, causing an `InvalidRequest` exception as all-zero vectors were not allowed matching Cassandra's behaviour.
To eliminate the discrepancy we want the all-zero vector `similarity_cosine` calls to pass, but return the NaN as the cosine similarity for zero vectors is mathematically incorrect. We decided not to use arbitrary values contrary to USearch, for which the distance (not to be confused with similarity) is defined as cos(0, 0) = 0, cos(0, x) = 1 while supporting the range of values [0, 2].
If we wanted to convert that to similarity, that would mean sim_cos(0, x) = 0.5, which does not support mathematical reasoning why that would be more similar than for example vectors marking obtuse angles.
It's safe to assume that all-zero vectors for cosine similarity shouldn't make any impact, therefore we return NaN and eliminate them from best results.
Adjusted the tests accordingly to check both proper Cassandra and Scylla's behaviour.
Fixes: SCYLLADB-456
Backport to 2026.1 needed, as it fixes the bug for ANN vector queries using rescoring introduced there.
Closesscylladb/scylladb#28609
* github.com:scylladb/scylladb:
test/vector_search: add reproducer for rescoring with zero vectors
vector_search: return NaN for similarity_cosine with all-zero vectors
Improves performance of deserialization of vector data for calculating similarity functions.
Instead of deserializing vector data into a std::vector<data_value>, we deserialize directly into a std::vector<float>
and then pass it to similarity functions as a std::span<const float>.
This avoids overhead of data_value allocations and conversions.
Example QPS of `SELECT id, similarity_cosine({vector<float, 1536>}, {vector<float, 1536>}) ...`:
client concurrency 1: before: ~135 QPS, after: ~1005 QPS
client concurrency 20: before: ~280 QPS, after: ~2097 QPS
Measured using https://github.com/zilliztech/VectorDBBench (modified to call above query without ANN search)
Fixes https://scylladb.atlassian.net/browse/SCYLLADB-471Closesscylladb/scylladb#28615
In b03d520aff ("cql3: introduce similarity functions syntax") we
added vector similarity functions to the grammar. The grammar had to
be modified because we wanted to support literals as vector similarity
function arguments, and the general function syntax in selectors
did not allow that.
In cc03f5c89d ("cql3: support literals and bind variables in
selectors") we extended the selector function call grammar to allow
literals as function arguments.
Here, we remove the special case for vector similarity functions as
the general case in function calls covers all the possibilities the
special case does.
As a side effect, the vector similarity function names are no longer
reserved.
Note: the grammar change fixes an inconsistency with how the vector
similarity functions were evaluated: typically, when a USE statement
is in effect, an unqualified function is first matched against functions
in the keyspace, and only if there is no match is the system keyspace
checked. But with the previous implementation vector similarity functions
ignored the USE keyspace and always matched only the system keyspace.
This small inconsistency doesn't matter in practice because user defined
functions are still experimental, and no one would name a UDF to conflict
with a system function, but it is still good to fix it.
Closesscylladb/scylladb#28481
The ANN vector queries with all-zero vectors are allowed even on vector
indexes with similarity function set to cosine.
When enabling the rescoring option, those queries would fail as the rescoring
calls `similarity_cosine` function underneath, causing an `InvalidRequest` exception
as all-zero vectors were not allowed matching Cassandra's behaviour.
To eliminate the discrepancy we want the all-zero vector `similarity_cosine` calls to pass,
but return the NaN as the cosine similarity for zero vectors is mathematically incorrect.
We decided not to use arbitrary values contrary to USearch, for which the distance
(not to be confused with similarity) is defined as cos(0, 0) = 0, cos(0, x) = 1 while
supporting the range of values [0, 2].
If we wanted to convert that to similarity, that would mean sim_cos(0, x) = 0.5,
which does not support mathematical reasoning why that would be more similar than
for example vectors marking obtuse angles.
It's safe to assume that all-zero vectors for cosine similarity shouldn't make any impact,
therefore we return NaN and eliminate them from best results.
Adjusted the tests accordingly to check both proper Cassandra and Scylla's behaviour.
Fixes: SCYLLADB-456
Paxos state tables are internal tables fully managed by Scylla
and they shouldn't be exposed to the user nor they shouldn't be backed up.
This commit hides those kind of tables from all listings and if such table
is directly described with `DESC ks."tbl$paxos"`, the description is generated
withing a comment and a note for the user is added.
Fixes https://github.com/scylladb/scylladb/issues/28183
LWT on tablets and paxos state tables are present in 2025.4, so the patch should be backported to this version.
Closesscylladb/scylladb#28230
* github.com:scylladb/scylladb:
test/cqlpy: add reproducer for hidden Paxos table being shown by DESC
cql3/statements/describe_statement: hide paxos state tables
Add support for literals in the SELECT clause. This allows
SELECT fn(column, 4) or SELECT fn(column, ?).
Note, "SELECT 7 FROM tab" becomes valid in the grammar, but is still
not accepted because of failed type inference - we cannot infer the
type of 7, and don't have a favored type for literals (like C favors
int). We might relax this later.
In the WHERE clause, and Cassandra in the SELECT clause, type hints
can also resolve type ambiguity: (bigint)7 or (text)?. But this is
deferred to a later patch.
A few changes to the grammar are needed on top of adding a `value`
alternative to `unaliasedSelector`:
- vectorSimilarityArg gained access to `value` via `unaliasedSelector`,
so it loses that alternate to avoid ambiguity. We may drop
`vectorSimilarityArg` later.
- COUNT(1) became ambiguous via the general function path (since
function arguments can now be literals), so we remove this case
from the COUNT special cases, remaining with count(*).
- SELECT JSON and SELECT DISTINCT became "ambiguous enough" for
ANTLR to complain, though as far as I can tell `value` does not
add real ambiguity. The solution is to commit early (via "=>") to
a parsing path.
Due to the loss of count(1) recognition in the parser, we have to
special-case it in prepare. We may relax it to count any expression
later, like modern Cassandra and SQL.
Testing is awkward because of the type inference problem in top-level.
We test via the set_intersection() function and via lua functions.
Example:
```
cqlsh> CREATE FUNCTION ks.sum(a int, b int) RETURNS NULL ON NULL INPUT RETURNS int LANGUAGE LUA AS 'return a + b';
cqlsh> SELECT ks.sum(1, 2) FROM system.local;
ks.sum(1, 2)
--------------
3
(1 rows)
cqlsh>
```
(There are no suitable system functions!)
Fixes https://scylladb.atlassian.net/browse/SCYLLADB-296Closesscylladb/scylladb#28256
Schema is already a member of select statement, avoiding
the call saves around 400 cpu instructions on a select
request hot path.
Closesscylladb/scylladb#28328
We don't need a special guard value, it's
only being filled for batch statements for
which we can simply ignore the value.
Not having special value allows us to return
fast when audit is not enabled.
This series implements rescoring algorithm.
Index options allowing to enable this functionality were introduced in earlier PR https://github.com/scylladb/scylladb/pull/28165.
When Vector Index has enabled quantization, Vector Store uses reduced vector representation to save memory, but it may degrade correctness of ANN queries. For quantized index we can enable rescoring algorithm, which recalculates similarity score from full vector representation stored in Scylla and reorder returned result set.
It works also with oversampling - we fetch more candidates from Vector Store, rescore them at Scylla and return only requested number of results.
Example:
Creating a Vector Index with Rescoring
```sql
-- Create a table with a vector column
CREATE TABLE ks.products (
id int PRIMARY KEY,
embedding vector<float, 128>
);
-- Create a vector index with rescoring enabled
CREATE INDEX products_embedding_idx ON ks.products (embedding)
USING 'vector_index'
WITH OPTIONS = {
'similarity_function': 'cosine',
'quantization': 'i8',
'oversampling': '2.0',
'rescoring': 'true'
};
```
1. **Quantization** (`i8`) compresses vectors in the index, reducing memory usage but introducing precision loss in distance calculations
2. **Oversampling** (`2.0`) retrieves 2× more candidates than requested from the vector store (e.g., `LIMIT 10` fetches 20 candidates)
3. **Rescoring** (`true`) recalculates similarity scores using full-precision (`f32`) vectors from the base table and re-ranks results
Query example:
```sql
-- Find 10 most similar products
SELECT id, similarity_cosine(embedding, [0.1, 0.2, ...]) AS score
FROM ks.products
ORDER BY embedding ANN OF [0.1, 0.2, ...]
LIMIT 10;
```
With rescoring enabled, the query:
1. Fetches 20 candidates from the quantized index (due to oversampling=2.0)
2. Reads full-precision embeddings from the base table
3. Recalculates similarity scores with full precision
4. Re-ranks and returns the top 10 results
In this implementation we use CQL similarity function implementation to calculate new score values and use them in post query ordering. We add that column manually to selection, but it has to be removed from the final response.
Follow-up https://github.com/scylladb/scylladb/pull/28165
Fixes https://scylladb.atlassian.net/browse/SCYLLADB-83
New feature - doesn't need backport.
Closesscylladb/scylladb#27769
* github.com:scylladb/scylladb:
vector_index: rescoring: Fetch oversampled rows
vector_index: rescoring: Sort by similarity column
select_statement: Modify `needs_post_query_ordering` condition
vector_index: rescoring: Add hidden similarity score column
vector_index: Refactor extracting ANN query information
In 8df61f6d99 we changed the requirements for creating materialized
views and MV-based indexes - instead of requiring the
rf_rack_valid_keyspaces flag to be set, we now require the keyspace to
be RF-rack-valid at the time of creation, and it is enforced to remain
RF-rack-valid while the MV exists. This validation is done in the cql
create view/index statements.
The same should be done also for alternator - when creating a table with
GSI or LSI, or when adding a GSI to an existing table, previously we
required the flag rf_rack_valid_keyspaces to be set. Now we change it to
instead check if the keyspace is RF-rack-valid, and if not the operation
fails with an appropriate error.
Fixes https://github.com/scylladb/scylladb/issues/28214
backport to 2025.4 to add RF-rack-valid enforcements in alternator
Closesscylladb/scylladb#28154
* github.com:scylladb/scylladb:
locator: document the exception type of assert_rf_rack_valid_keyspace
alternator: don't require rf_rack flag for indexes, validate instead
In this PR we add a basic implementation of the strongly-consistent tables:
* generate raft group id when a strongly-consistent table is created
* persist it into system.tables table
* start raft groups on replicas when a strongly-consistent tablet_map reaches them
* add strongly-consistent version of the storage_proxy, with the `query` and `mutate` methods
* the `mutate` method submits a command to the tablets raft group, the query method reads the data with `raft.read_barrier()`
* strongly-consistent versions of the `select_statement` and `modification_statement` are added
* a basic `test_strong_consistency.py/test_basic_write_read` is added which to check that we can write and read data in a strongly consistent fashion.
Limitations:
* for now the strongly consistent tables can have tablets only on shard zero. This is because we (ab/re) use the existing raft system tables which live only on shard0. In the next PRs we'll create separate tables for the new tablets raft groups.
* No Scylla-side proxying - the test has to figure out who is the leader and submit the command to the right node. This will be fixed separately.
* No tablet balancing -- migration/split/merges require separate complicated code.
The new behavior is hidden behind `STRONGLY_CONSISTENT_TABLES` feature, which is enabled when the `STRONGLY_CONSISTENT_TABLES` experimental feature flag is set.
Requirements, specs and general overview of the feature can be found [here](https://scylladb.atlassian.net/wiki/spaces/RND/pages/91422722/Strong+Consistency). Short term implementation plan is [here](https://docs.google.com/document/d/1afKeeHaCkKxER7IThHkaAQlh2JWpbqhFLIQ3CzmiXhI/edit?tab=t.0#heading=h.thkorgfek290)
One can check the strongly consistent writes and reads locally via cqlsh:
scylla.yaml:
```
experimental_features:
- strongly-consistent-tables
```
cqlsh:
```
CREATE KEYSPACE IF NOT EXISTS my_ks WITH replication = {'class': 'NetworkTopologyStrategy', 'replication_factor': 1} AND tablets = {'initial': 1} AND consistency = 'local';
CREATE TABLE my_ks.test (pk int PRIMARY KEY, c int);
INSERT INTO my_ks.test (pk, c) VALUES (10, 20);
SELECT * FROM my_ks.test WHERE pk = 10;
```
Fixes SCYLLADB-34
Fixes SCYLLADB-32
Fixes SCYLLADB-31
Fixes SCYLLADB-33
Fixes SCYLLADB-56
backport: no need
Closesscylladb/scylladb#27614
* https://github.com/scylladb/scylladb:
test_encryption: capture stderr
test/cluster: add test_strong_consistency.py
raft_group_registry: disable metrics for non-0 groups
strong consistency: implement select_statement::do_execute()
cql: add select_statement.cc
strong consistency: implement coordinator::query()
cql: add modification_statement
cql: add statement_helpers
strong consistency: implement coordinator::mutate()
raft.hh: make server::wait_for_leader() public
strong_consistency: add coordinator
modification_statement: make get_timeout public
strong_consistency: add groups_manager
strong_consistency: add state_machine and raft_command
table: add get_max_timestamp_for_tablet
tablets: generate raft group_id-s for new table
tablet_replication_strategy: add consistency field
tablets: add raft_group_id
modification_statement: remove virtual where it's not needed
modification_statement: inline prepare_statement()
system_keyspace: disable tablet_balancing for strongly_consistent_tables
cql: rename strongly_consistent statements to broadcast statements
The function assert_rf_rack_valid_keyspace uses the exception type
std::invalid_argument when the RF-rack validation fails. Document it and
change all callers to catch this specific exception type when checking
for RF-rack validation failures, so that other exception types can be
propagated properly.
So far with oversampling the extended set of keys was returned from VS,
but query to the base table was still limited by the query `limit`.
Now for rescoring we want to fetch rows for all the keys returned from VS.
However later we need to restore the command limit, to trim result_set accordingly.
For non-rescoring scenarios we trim directly keys set returned from VS if it happens to exceed query limit.
With this change rescoring validation tests (except `no_nulls_in_rescored_results`) pass fully.
Fixes https://scylladb.atlassian.net/browse/SCYLLADB-83
This patch implements second part of rescoring - ordering results by similarity column added in earlier patch.
For this purpose in this patch we define `_ordering_comparator`, which enables pre-existing post-query ordering functionality.
However, none additional test passes yet, as they include ovesampling, which will be the subject of following patches.
Our plan for rescoring is to use the existing post-query ordering mechanism to sort (and trim) result_set by similarity column.
For general SELECT case this ordering is permitted only for queries with IN on the partition key and an ORDER BY, which is checked in `needs_post_query_ordering`.
Recently this check was overriden for ANN queries in https://github.com/scylladb/scylladb/pull/28109 to enable IN queries handled by VS without excessive post-processing.
In this patch we revert that change - ANN case will be handled by general check.
However we change the condition - we will enable post processing anytime `_ordering_comparator` is set.
In current implementation `_ordering_comparator` is created only in `select_statement::prepare` with `get_ordering_comparator`,
only for the same conditions as were checked in `needs_post_query_ordering`, so this change should be transparent for general SELECT.
For ANN query it is also not set (yet), so it will not influence ANN filtering, but we confirm that this functionality still works
by adding filtering test: `test/vector_search/filter_test.cc::vector_store_client_test_filtering_ann_cql`.
Rescoring ordering for ANN queries will be enabled when we add `_ordering_comparator` in following patch.
Rescoring consist of recalculating similarity score and reordering results based on it.
In this patch we add calculation of similarity score as a hidden (non-serialized) column and following patch will add reordering.
Normal ordering uses `add_column_for_post_processing`, however this works only for regular columns, not function.
So we create it together with user requested columns (this also forces the use of `selection_with_processing`) and hide the column later.
This also requires special handling for 'SELECT *' case - we need to manually add all columns before adding similarity column.
In case user already asks for similarity score in the SELECT clause, this value will be calculated twice - is should be optimized in future patches.
For the purpose of rescoring we will need information if the query is an ANN query
and the access to index option earlier in the `select_statement::prepare` than it happened before.
This patch refactors extracting this information to new helper structure `ann_ordering_info`
and is consistently using it.
Add enforce_rack_list option. When the option is set to true,
all tablet keyspaces have rack list replication factor.
When the option is on:
- CREATE STATEMENT always auto-extends rf to rack lists;
- ALTER STATEMENT fails when there is numeric rf in any DC.
The flag is set to false by default and a node needs to be restarted
in order to change its value. Starting a node with enforce_rack_list
option will fail, if there are any tablet keyspaces with numeric rf
in any DC.
enforce_rack_list is a per-node option and a user needs to ensure
that no tablet keyspace is altered or created while nodes in
the cluster don't have the consistent value.
Mark rf_rack_valid_keyspaces as deprecated.
Fixes: https://github.com/scylladb/scylladb/issues/26399.
New feature; no backport needed
Closesscylladb/scylladb#28084
* github.com:scylladb/scylladb:
test: add test for enforce_rack_list option
db: mark rf_rack_valid_keyspaces as deprecated
config: add enforce_rack_list option
Revert "alternator: require rf_rack_valid_keyspaces when creating index"
In PR 5b6570be52 we introduced the config option `sstable_compression_user_table_options` to allow adjusting the default compression settings for user tables. However, the new option was hooked into the CQL layer and applied only to CQL base tables, not to the whole spectrum of user tables: CQL auxiliary tables (materialized views, secondary indexes, CDC log tables), Alternator base tables, Alternator auxiliary tables (GSIs, LSIs, Streams).
This gap also led to inconsistent default compression algorithms after we changed the option’s default algorithm from LZ4 to LZ4WithDicts (adf9c426c2).
This series introduces a general “schema initializer” mechanism in `schema_builder` and uses it to apply the default compression settings uniformly across all user tables. This ensures that all base and aux tables take their default compression settings from config.
Fixes#26914.
Backport justification: LZ4WithDicts is the new default since 2025.4, but the config option exists since 2025.2. Based on severity, I suggest we backport only to 2025.4 to maintain consistency of the defaults.
Closesscylladb/scylladb#27204
* github.com:scylladb/scylladb:
db/config: Update sstable_compression_user_table_options description
schema: Add initializer for compression defaults
schema: Generalize static configurators into schema initializers
schema: Initialize static properties eagerly
db: config: Add accessor for sstable_compression_user_table_options
test: Check that CQL and Alternator tables respect compression config
We use decoration instead of inheritance, since inheritance already
serves to differentiate statement types (modification_statement has
update_statement and delete_statement as descendants). A better
solution would likely involve refactoring modification_statement and
extracting the mutation-generation logic into a reusable component
shared by both eventual and strongly consistent statements.
Introduce two helper methods that will be used for strongly consistent
select_statement and modification_statement.
redirect_statement() forwards the request to another shard or node.
Currently, only shard forwarding is implemented; node-level proxying
will be added in follow-up PRs.
is_strongly_consistent() will be used in the prepare() method of raw
statements to determine whether a strongly consistent statement should
be created for the given CQL statement.
Add the `coordinator` class, which will be responsible for coordinating
reads and writes to strongly consistent tables. This commit includes
only the boilerplate; the methods will be implemented in separate
commits.
This is a refactoring/simplification commit.
There are many 'prepare' functions in this class that don't
meaningfully differ from each other. The prepare_statement() adds
accidental complexity by adding a level of indirection -- the reader
has to jump between the call site and the function body to reconstruct
the full picture.
In preparation for upcoming work on strongly consistent queries in
Scylla, this commit renames the existing `strongly_consistent`
statements to `broadcast_statements` to avoid confusion.
The old code paths are kept temporarily, as they may be useful for
reference or for copying parts during the implementation of the new
strongly consistent statements.
Auth v2 migration uses non-paged queries via `execute_internal` API.
This commit changes it to use `query_internal` instead, which uses
paging under the hood.
Fixes: https://github.com/scylladb/scylladb/issues/27577
A minor enhancement, no need to backport.
Closesscylladb/scylladb#25395
* github.com:scylladb/scylladb:
auth: use paged internal queries during migration
auth: move some code in migrate_to_auth_v2 up
auth: re-align pieces of migrate_to_auth_v2
cql: extend `query_internal` with `query_state` param
Add `prepared_filter` class which handles the preparation, construction
and caching of Vector Search filtering compatible JSON object.
If no bind markers found in SELECT statement, the JSON object will be built
once at prepare time and cached for use during execution calls.
Adjust tests accordingly to use prepared filters.
Follow-up: #28109
Fixes: SCYLLADB-299
Paxos state tables are internal tables fully managed by Scylla
and they shouldn't be exposed to the user nor they shouldn't be backed up.
This commit hides those kind of tables from all listings and if such table
is directly described with `DESC ks."tbl$paxos"`, the description is generated
withing a comment and a note for the user is added.
Fixesscylladb/scylladb#28183
Move Vector Search filter functions from `cql3::restrictions` to
`vector_search` namespace as it's a better place according to
it's purpose.
The effective name has now changed from `cql3::restrictions::to_json`
to `vector_search::to_json` which clearly mentions that the JSON
object will be used for Vector Search.
Rename the auxilary functions to use `to_json` suffix instead of
variety of verbs as those functions logic focuses on building JSON
object from different structures. The late naming emphasized too
much distinction between those functions, while they do pretty much
the same thing.
Follow-up: #28109
Add enforce_rack_list option. When the option is set to true,
all tablet keyspaces have rack list replication factor.
When the option is on:
- CREATE STATEMENT always auto-extends rf to rack lists;
- ALTER STATEMENT fails when there is numeric rf in any DC.
The flag is set to false by default and a node needs to be restarted
in order to change its value. Starting a node with enforce_rack_list
option will fail, if there are any tablet keyspaces with numeric rf
in any DC.
enforce_rack_list is a per-node option and a user needs to ensure
that no tablet keyspace is altered or created while nodes in
the cluster don't have the consistent value.
This patch adds vector index options allowing to enable quantization and oversampling.
Specific quantization value will be used internally by vector store.
In the current implementation, `get_oversampling` allows us to decide how many times more candidates
to retrieve from vector store - final response is still trimmed to the given limit.
It is a first step to allow rescoring - recalculation of similarity metric and re-ranking.
Without rescoring oversampling will be also further optimized to happen internally in vector store.
Fixes https://scylladb.atlassian.net/browse/SCYLLADB-82
Ref https://scylladb.atlassian.net/browse/SCYLLADB-83
Since Vector Store service filtering API has been implemented (scylladb/vector-store#334), there is a need for the implementation of Scylla side part.
This patch should implement a `statement_restrictions` parsing into Vector Store filtering API compatible JSON objects.
Those objects should be added to ANN query vector POST requests as `filter` object.
After this patch, the subset of all operations ([Vector Search Filtering Milestone 1](https://scylladb.atlassian.net/wiki/spaces/RND/pages/156729450/Vector+Search+Filtering+Design+Document#Milestone-1)) happy path should be completed, allowing users to filter on primary key columns with single column `=` and `IN` or multiple column `()=()` and `() IN ()`.
The restrictions for other operations should be implemented in a PR on Vector Store service side.
---
This PR implements parsing the `statement_restrictions` into Vector Store filtering API compatible JSON objects.
The JSON objects are created and used in ANN vector queries with filtering.
It closes the Scylla side implementation of Vector Search filtering milestone 1.
Unit tests for `statement_restrictions` parsing are added. Integration tests will be added on Vector Store service side PR.
---
Fixes: SCYLLADB-249
New feature, should land into 2026.1
Closesscylladb/scylladb#28109
* github.com:scylladb/scylladb:
docs: update documentation on filtering with vector queries
test/vector_search: add test for filtered ANN with VS mock
test/vector_search: add restriction to JSON conversion unit tests
vector_search: cql: construct and use filter in ANN vector queries
select_statement: do not require post query ordering for vector queries
vector_search: add `statement_restrictions` to JSON parsing
Add `filter` option in `ann()` function to write the filter JSON
object as the POST request in ANN vector queries.
Adjust existing `vector_store_client_test` tests accordingly.
As there is only one `ORDER BY` clause with `ANN OF` ordering supported
in ANN vector queries, there is no need to require post query ordering
for the ANN vector queries. The standard ordering is not allowed here.
In fact the ordering is done on the Vector Store service side within
the ANN search, so that the returned primary keys are already sorted
accordingly.
If left unchanged, the filtering with `IN` clauses would cause
a `bad_function_call` server error as the filtering with `IN` clauses
require the post query ordering in a standard case.
Problem
-------
Secondary indexes are implemented via materialized views under the
hood. The way an index behaves is determined by the configuration
of the view. Currently, it can be modified by performing the CQL
statement `ALTER MATERIALIZED VIEW` on it. However, that raises some
concerns.
Consider, for instance, the following scenario:
1. The user creates a secondary index on a table.
2. In parallel, the user performs writes to the base table.
3. The user modifies the underlying materialized view, e.g. by setting
the `synchronous_updates` to `true` [1].
Some of the writes that happened before step 3 used the default value
of the property (which is `false`). That had an actual consequence
on what happened later on: the view updates were performed
asynchronously. Only after step 3 had finished did it change.
Unfortunately, as of now, there is no way to avoid a situation like
that. Whenever the user wants to configure a secondary index they're
creating, they need to do it in another schema change. Since it's
not always possible to control how the database is manipulated in
the meantime, it leads to problems like the one described.
That's not all, though. The fact that it's not possible to configure
secondary indexes is inconsistent with other schema entities. When
it comes to tables or materialized views, the user always have a means
to set some or even all of the properties during their creation.
Solution
--------
The solution to this problem is extending the `CREATE INDEX` CQL
statement by view properties. The syntax is of form:
```
> CREATE INDEX <index name>
> .. ON <keyspace>.<table> (<columns>)
> .. WITH <properties>
```
where `<properties>` corresponds to both index-specific and view
properties [2, 3]. View properties can only be used with indexes
implemented with materialized views; for example, it will be impossible
to create a vector index when specifying any view property (see
examples below).
When a view property is provided, it will be applied when creating the
underlying materialized view. The behavior should be similar to how
other CQL statements responsible for creating schema entities work.
High-level implementation strategy
----------------------------------
1. Make auxiliary changes.
2. Introduce data structures representing the new set of index
properties: both index-specific and those corresponding to the
underlying view.
3. Extend `CREATE INDEX` to accept view properties.
4. Extend `DESCRIBE INDEX` and other `DESCRIBE` statements to include
view properties in their output.
User documentation is also updated at the steps to reflect the
corresponding changes.
Implementation considerations
-----------------------------
There are a number of schema properties that are now obsolete. They're
accepted by other CQL statements, but they have no effect. They
include:
* `index_interval`
* `replicate_on_write`
* `populate_io_cache_on_flush`
* `read_repair_chance`
* `dclocal_read_repair_chance`
If the user tries to create a secondary index specifying any of those
keywords, the statement will fail with an appropriate error (see
examples below).
Unlike materialized views, we forbid specifying the clustering order
when creating a secondary index [4]. This limitation may be lifted
later on, but it's a detail that may or may not prove troublesome. It's
better to postpone covering it to when we have a better perspective on
the consequences it would bring.
Examples
--------
Good examples
```
> CREATE INDEX idx ON ks.t (v);
> CREATE INDEX idx ON ks.t (v) WITH comment = 'ok view property';
> CREATE INDEX idx ON ks.t (v)
.. WITH comment = 'multiple view properties are ok'
.. AND synchronous_updates = true;
> CREATE INDEX idx ON ks.t (v)
.. WITH comment = 'default value ok'
.. AND synchronous_updates = false;
```
Bad examples
```
> CREATE INDEX idx ON ks.t (v) WITH replicate_on_write = true;
SyntaxException: Unknown property 'replicate_on_write'
> CREATE INDEX idx ON ks.t (v)
.. WITH OPTIONS = {'option1': 'value1'}
.. AND comment = 'some text';
InvalidRequest: Error from server: code=2200 [Invalid query]
message="Cannot specify options for a non-CUSTOM index"
> CREATE CUSTOM INDEX idx ON ks.t (v)
.. WITH OPTIONS = {'option1': 'value1'}
.. AND comment = 'some text';
InvalidRequest: Error from server: code=2200 [Invalid query]
message="CUSTOM index requires specifying the index class"
> CREATE CUSTOM INDEX idx ON ks.t (v)
.. USING 'vector_index'
.. WITH OPTIONS = {'option1': 'value1'}
.. AND comment = 'some text';
InvalidRequest: Error from server: code=2200 [Invalid query]
message="You cannot use view properties with a vector index"
> CREATE INDEX idx ON ks.t (v) WITH CLUSTERING ORDER BY (v ASC);
InvalidRequest: Error from server: code=2200 [Invalid query]
message="Indexes do not allow for specifying the clustering order"
```
and so on. For more examples, see the relevant tests.
References:
[1] https://docs.scylladb.com/manual/branch-2025.4/cql/cql-extensions.html#synchronous-materialized-views
[2] https://docs.scylladb.com/manual/branch-2025.4/cql/secondary-indexes.html#create-index
[3] https://docs.scylladb.com/manual/branch-2025.4/cql/mv.html#mv-options
[4] https://docs.scylladb.com/manual/branch-2025.4/cql/dml/select.html#ordering-clauseFixesscylladb/scylladb#16454
Backport: not needed. This is an enhancement.
Closesscylladb/scylladb#24977
* github.com:scylladb/scylladb:
cql3: Extend DESC INDEX by view properties
cql3: Forbid using CLUSTERING ORDER BY when creating index
cql3: Extend CREATE INDEX by MV properties
cql3/statements/create_index_statement: Allow for view options
cql3/statements/create_index_statement: Rename member
cql3/statements/index_prop_defs: Re-introduce index_prop_defs
cql3/statements/property_definitions: Add extract_property()
cql3/statements/index_prop_defs.cc: Add namespace
cql3/statements/index_prop_defs.hh: Rename type
cql3/statements/view_prop_defs.cc: Move validation logic into file
cql3/statements: Introduce view_prop_defs.{hh,cc}
cql3/statements/create_view_statement.cc: Move validation of ID
schema/schema.hh: Do not include index_prop_defs.hh
In PR 5b6570be52 we introduced the config option
`sstable_compression_user_table_options` to allow adjusting the default
compression settings for user tables. However, the new option was hooked
into the CQL layer and applied only to CQL base tables, not to the whole
spectrum of user tables: CQL auxiliary tables (materialized views,
secondary indexes, CDC log tables), Alternator base tables, Alternator
auxiliary tables (GSIs, LSIs, Streams).
Fix this by moving the logic into the `schema_builder` via a schema
initializer. This ensures that the default compression settings are
applied uniformly regardless of how the table is created, while also
keeping the logic in a central place.
Register the initializer at startup in all executables where schemas are
being used (`scylla_main()`, `scylla_sstable_main()`, `cql_test_env`).
Finally, remove the ad-hoc logic from `create_table_statement`
(redundant as of this patch), remove the xfail markers from the relevant
tests and adjust `test_describe_cdc_log_table_create_statement` to
expect LZ4WithDicts as the default compressor.
Fixes#26914.
Signed-off-by: Nikos Dragazis <nikolaos.dragazis@scylladb.com>
The `sstable_compression_user_table_options` config option determines
the default compression settings for user tables.
In patch 2fc812a1b9, the default value of this option was changed from
LZ4 to LZ4WithDicts and a fallback logic was introduced during startup
to temporarily revert the option to LZ4 until the dictionary compression
feature is enabled.
Replace this fallback logic with an accessor that returns the correct
settings depending on the feature flag. This is cleaner and more
consistent with the way we handle the `sstable_format` option, where the
same problem appears (see `get_preferred_sstable_version()`).
As a consequence, the configuration option must always be accessed
through this accessor. Add a comment to point this out.
Signed-off-by: Nikos Dragazis <nikolaos.dragazis@scylladb.com>
