ScalarDB 3.18 Release Notes

This page includes a list of release notes for ScalarDB 3.18.

v3.18.0

Release date: May 1, 2026

Summary

This release includes a lot of enhancements, improvements, security issue fixes, and bug fixes.

Backward-incompatible changes

• JDBC connection pool migrated from Apache Commons DBCP2 to HikariCP:
  • The following configuration properties are no longer supported. They are ignored, with a warning logged, if set:
    • scalar.db.jdbc.connection_pool.max_idle
    • scalar.db.jdbc.table_metadata.connection_pool.max_idle
    • scalar.db.jdbc.admin.connection_pool.max_idle
    • scalar.db.jdbc.prepared_statements_pool.enabled
    • scalar.db.jdbc.prepared_statements_pool.max_open
  • Prepared statement pooling is no longer available because HikariCP has no equivalent feature.
  • Connection pool default behavior follows HikariCP rather than DBCP2, which may change runtime behavior even without configuration changes (for example, connection acquisition timeout and idle eviction).
• Existing tables require repairTable() to create the new before-image secondary index. Index-based Get, Scan, and ScanAll in Consensus Commit now rely on a companion before_<col> index. Until you run repairTable() on each existing table, ScalarDB logs a warning at startup and index-based reads fall back to the previous behavior, which may miss records whose indexed column is being concurrently updated. The configuration scalar.db.consensus_commit.index.eventually_consistent_read.enabled is provided as an opt-out but is not recommended for new workloads.
• MySQL Connector/J replaced with MariaDB Connector/J. SSL is no longer enabled by default. If you connect to MySQL 8.0 or later with caching_sha2_password authentication, add sslMode=REQUIRED or allowPublicKeyRetrieval=true to your JDBC URL. No action is required for jdbc:mysql:// URLs because ScalarDB automatically appends permitMysqlScheme for compatibility.
• BigIntColumn.MAX_VALUE and BigIntColumn.MIN_VALUE constants have been removed. Code that referenced them must use Long.MAX_VALUE and Long.MIN_VALUE instead.

Community edition

Enhancements

• Added AuthAdmin.getRole(roleName). (#3238)
• Added operation-level attributes to allow cross-partition scan, filtering, and ordering on a per-operation basis without requiring global configuration. (#3425)
• Added DistributedTransactionAdmin.hasPrivilege(). (#3432)
• Added AuthenticationMethod enum and authentication-method-aware user management APIs to AuthAdmin to support OIDC authentication. (#3433)
• Added attributes parameter to DistributedTransactionManager begin and start methods, enabling transaction-scoped attribute configuration. CRUD methods on DistributedTransactionManager also pass the operation's attributes to the internally begun transaction. Also added support for specifying the isolation level per transaction in Consensus Commit via the cc-transaction-isolation attribute. (#3466 #3517 #3540)
• Added support for Google Cloud Spanner as a JDBC storage, via its PostgreSQL-compatible dialect. (#3510)

Improvements

• Extended the applicability of one-phase commit optimization in the Consensus Commit protocol. This allows one-phase commit to be used even in SERIALIZABLE isolation level when the transaction only reads records that it subsequently updates, improving performance for read-modify-write workloads. (#3295)
• Added batch execution support for mutate operations in the JDBC adapter to improve performance when executing multiple mutations. Mutations with the same SQL statement are now grouped and executed as a batch. (#3304)
• Migrated the JDBC adapter's connection pooling library from Apache Commons DBCP2 to HikariCP for improved performance and reliability. (#3305)
• Changed the behavior of Consensus Commit transactions to allow Insert/Upsert/Update operations after Delete on the same record within the same transaction. Previously, this operation threw an IllegalArgumentException, but now it properly handles the case by treating it as a new record insertion with null values for unspecified columns. (#3319)
• Added @CheckReturnValue annotation to Get/Scan builders. (#3320)
• Added support for setting null values on secondary index columns in DynamoDB. When a null value is set, the attribute is removed from the item and the record will not appear in secondary index scans. (#3326)
• Inserting or updating records with TIME (microsecond precision), TIMESTAMP (millisecond precision), and TIMESTAMPTZ (millisecond precision) column values will truncate out-of-range precision rather than throwing an exception. (#3393)
• Fixed a correctness issue in index-based Get, Scan, and ScanAll operations in Consensus Commit where records whose indexed column was being concurrently updated by another transaction could be missed. ScalarDB now maintains a companion before-image secondary index for each user-defined secondary index on a non-primary-key column and uses it to recover PREPARED/DELETED records during index reads. (#3419 #3463)
• Replaced MySQL Connector/J with MariaDB Connector/J to resolve GPLv2 licensing concerns. (#3428)
• Shortened JDBC index names using a hash when they exceed the maximum identifier length supported by the underlying database. (#3481)
• Relaxed the BigInt value range restriction (-2^53 to 2^53) that previously applied to all storage backends. This restriction now only applies to Cosmos DB and Object Storage. Other backends (JDBC, Cassandra, DynamoDB) now support the full Java long range for BigInt columns. (#3490)
• Changed the Oracle BIGINT column type mapping from NUMBER(16) to NUMBER(19) to support the full Java long range. (#3507)
• Changed the deprecation policy so that APIs and configurations marked as deprecated will now be removed in 4.0.0 instead of 5.0.0. (#3520)

Bug fixes

• Fixed option issues in Object Storage adapter. (#3237)
• On Oracle, when importing a table with a column using the NUMBER(1) data type, which is usually used for BOOLEAN data, that column can now be mapped to ScalarDB BOOLEAN using ScalarDB Schema Loader override-columns-type setting. (#3239)
• Fix to increase the maximum allowed string length with Object Storage. (#3248)
• Updated the upper limit value displayed in the error message for data size limitation in Object Storage adapter. (#3264)
• Added explicit commits for Oracle database when using SERIALIZABLE isolation level to ensure snapshot updates after each operation. (#3294)
• Upgraded the Jackson library to fix a security issue: GHSA-72hv-8253-57qq (#3394)
• Fix dropColumnFromTable() dropping the secondary index even when column drop is unsupported. (#3450)
• Upgraded the Netty library to fix security issues: CVE-2026-33870 and CVE-2026-33871 (#3452)
• Fixed a bug where index-based Get and Scan operations could return incorrect results after lazy recovery rolled back a PREPARED record whose after-image index value matched the query but whose before-image (restored) value did not. (#3488)

Enterprise edition

Enhancements

ScalarDB Cluster

• Added getRole() API and equivalent to retrieve a single role by name.
• Added support for starting replication with existing backup site tables.
• Added support for the executeBatch API in ScalarDB Cluster SQL transactions, enabling batch execution of multiple SQL statements in a single call.
• Added client-side optimizations for SQL transactions (piggyback_begin and write_buffering) to reduce RPC overhead between the client and the cluster.
• Added support for configuring a separate gRPC port for the admin service by using the scalar.db.cluster.node.admin.port property.
• Added DistributedTransactionAdmin.hasPrivilege() to check if a specified user has a specific privilege on a table.
• Added support for the attributes parameter in transaction begin/start methods, enabling transaction-scoped configuration such as isolation level.
• Added OIDC JWT authentication support.
• Added ThreadLocal-based user-password authentication support via CredentialsHolder, allowing multiple users to share a single TransactionManager.
• Added property-based OIDC JWT authentication support for the client, allowing JWT access tokens to be passed via configuration properties.

ScalarDB SQL

• Added Metadata.getRole(roleName)
• Added support for Spring Boot 4 in Spring Data JDBC for ScalarDB.
• Added support for extending AbstractJdbcConfiguration for custom bean configuration in Spring Data JDBC for ScalarDB.
• Changed the PreparedStatement API to use bind() methods that return a BoundStatement for parameter binding, instead of directly setting values on PreparedStatement.
• Added executeBatch API to execute multiple statements in a single call, with support in the core SQL API, direct-mode, and JDBC driver.
• Added support for BLOB literals using X'hex' syntax in SQL statements.
• Added support for AuthenticationMethod in CREATE/ALTER USER and SHOW USERS
• Added support for specifying transaction-scoped attributes in BEGIN and START TRANSACTION SQL statements using the WITH clause (e.g., BEGIN WITH 'cc-transaction-isolation' = 'SNAPSHOT'). Also added begin(Map), and beginReadOnly(Map) methods to SqlSession for programmatic attribute specification.
• Updated SqlJdbcDatabaseMetaData.getUserName() to return the authenticated user name via Metadata.getCurrentUser().
• Added support for specifying ABAC read and write tags in the WITH clause of BEGIN and START TRANSACTION statements.

Improvements

ScalarDB Cluster

• Refactored internal auth token handling to use a type-safe class hierarchy instead of string prefix parsing.
• Auth, ABAC, and Encryption modules no longer require scalar.db.cross_partition_scan.enabled=true to be enabled globally. These modules now use operation-level cross-partition scan attributes and run internal metadata transactions with Snapshot Isolation.
• Changed the deprecation policy so that APIs marked as deprecated will now be removed in 4.0.0 instead of 5.0.0.

ScalarDB GraphQL

• Relaxed the range of values accepted by the GraphQL BigInt scalar to the full Java long range, aligning with the corresponding relaxation in ScalarDB. Backend-specific limits (Cosmos DB and Object Storage still restrict BigInt to -2^53 to 2^53) are now enforced by ScalarDB at the storage layer rather than by the GraphQL layer.

ScalarDB SQL

• Improve thread pool management in two-phase commit interface transaction to avoid potential starvation issues in Spring Data JDBC for ScalarDB.
• Added one-operation mode support for one-shot query execution to improve performance by skipping explicit transaction begin/commit when the SQL query can be expressed as a single operation.
• Inserting or updating records with TIME (microsecond precision), TIMESTAMP (millisecond precision), and TIMESTAMPTZ (millisecond precision) column values will truncate out-of-range precision rather than throwing an exception.
• Fixed an issue where the shadow jar was unnecessarily published to GitHub Packages for the CLI module.
• Update the TIMESTAMPTZ literal to make optional the space character before the UTC timezone Z character. For example, 2021-03-04 12:30:45.123Z is now accepted, in addition to the current format 2021-03-04 12:30:45.123 Z. Also, when selecting a TIMESTAMPTZ column, the value is printed without a space before the Z.
• Refactored the SQL statement builder APIs for improved type safety and ergonomics. SelectStatementBuilder now enforces SQL clause ordering at the type level so that having() is only callable after groupBy(), and HAVING supports the same fluent .and(...) / .or(...) chain as WHERE; Having.of(...) factories have been consolidated into Having.create(...); CreateUserStatementBuilder / AlterUserStatementBuilder expose explicit withPassword() / withSuperuser() / withNoSuperuser() methods in place of the previous overloaded with(...); the UserOption enum has been removed in favor of a nullable superuser boolean on CreateUserStatement / AlterUserStatement; and FunctionRef now provides convenience factories (count(), sum(...), avg(...), min(...), max(...)) for common aggregates.

Bug fixes

ScalarDB Cluster

• Made GRANT ROLE command idempotent, allowing duplicate grants and upgrading to WITH ADMIN OPTION when re-granting.
• Fixed a bug where ScalarDB Cluster cannot be deployed in the Omnistrate environment by upgrading scalar-metering.
• Fixed a bug where the pause functionality did not work correctly when transactions expired.
• Fixed an issue where the batch operation with piggyback commit threw CrudException instead of CrudConflictException when a commit conflict occurred. This allows clients to properly detect and handle commit conflicts.
• Fixed a bug where batch() with piggyback commit threw CrudException instead of UnknownTransactionStatusException on unexpected gRPC errors. This could cause incorrect error handling on the client side, as the transaction status was actually unknown when piggyback commit was enabled.
• Upgraded grpc_health_probe to fix security issues: CVE-2025-68121, CVE-2025-61726, CVE-2025-61728, CVE-2025-61729, and CVE-2025-61730
• Excluded com.microsoft.azure:adal4j from the Kubernetes Java Client to fix security issues: CVE-2023-52428, CVE-2021-31684, and CVE-2023-1370
• Upgraded the Jackson library to fix a security issue: GHSA-72hv-8253-57qq
• Upgraded grpc_health_probe to fix security issues: CVE-2025-59250 and CVE-2026-25679
• Upgraded the Netty library to fix security issues: CVE-2026-33870 and CVE-2026-33871
• Fixed a bug where one-shot batch operations bypassed pause control in the GateKept transaction managers.
• Upgraded grpc_health_probe to fix a security issue: CVE-2026-34986.

ScalarDB SQL

• Ambiguous column names in ORDER BY and HAVING clauses were detected.
• Fixed a ClassCastException that occurred in StatementUtils.appendTerm() when handling DATE, TIME, TIMESTAMP, and TIMESTAMPTZ values. These values are now correctly formatted as string literals instead of being incorrectly cast to String.
• Fixed SelectStatement.toSql() to correctly generate ORDER BY clauses with aggregate functions such as SUM() and COUNT(). Previously, only column-based orderings were handled, causing incorrect SQL output when function-based orderings were used.
• Fixed a bug where duplicate column names were allowed in CREATE TABLE statements.
• Fixed missing strict date validation on time-related type formatters, which could allow invalid dates (e.g., February 30) to be silently accepted instead of rejected.
• ResultSet.getObject on BLOB columns now returns a java.sql.Blob, and ResultSet.getBlob, ResultSet.getBinaryStream, and several PreparedStatement.setBlob / setBinaryStream overloads are now supported. ResultSetMetaData.getColumnType for FLOAT columns now returns Types.REAL (previously Types.FLOAT). ResultSet.getString now returns Java null for SQL NULL instead of the literal string "null", in line with the JDBC spec. As a side effect, the SQL CLI now renders BLOB values as X'...' hex literals instead of [B@xxxxxxxx.
• Fixed an issue where CachedMetadata#invalidateNamespaceNamesCache() did not actually invalidate the cached list of namespaces, causing SHOW NAMESPACES and related operations to potentially return stale results until the cache TTL expired.

Enterprise Options

ScalarDB Analytics

Enhancements

• Password authentication with access token support.
• Internal user directory management.
• gRPC authentication interceptor.
• SDK and CLI authentication with token caching.
• Spark data source authentication support.
• ScalarDB Cluster password authentication backend.
• gRPC retry with exponential backoff for Client SDK.

Improvements

• Set scan fetch size to 4096 for JDBC and ScalarDB data sources.

Breaking changes

• Unify ScalarDB namespace to scalardb_analytics and add domain prefixes to table names (registry_, auth_) to avoid PostgreSQL identifier length limits.

Bug fixes

• Use TIMESTAMPTZ instead of TIMESTAMP for temporal columns.