OceanBase 4.4.2_CE_BP1 Release: Vector Search, Zone-Level TableGroups, and Experimental Strong Sync

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OceanBase 4.4.2_CE_BP1 Release: Vector Search, Zone-Level TableGroups, and Experimental Strong Sync

Released on May 8, 2026, OceanBase v4.4.2_CE_BP1 is a significant update focusing on high availability, vector search capabilities, and performance tuning. The release introduces experimental strong sync for zero RPO, Zone-level TableGroups to better control partition leader distribution, and expanded vector search features. It also brings MySQL 8.0 dual password compatibility and various schema and configuration changes.

Supported Upgrade Paths

Administrators can upgrade to this version from the following paths:

  • V4.2.5_CE or V4.2.5_CE BP1~BP6 → V4.2.5_CE BP7 → V4.4.2_CE BP1
  • V4.3.5_CE or V4.3.5_CE BP1~BP5 → V4.3.5_CE BP6 → V4.4.2_CE BP1
  • V4.4.1_CE → V4.4.2_CE BP1

Key Features and Enhancements

Experimental Strong Sync (RPO=0)

This release introduces strong synchronization between primary and standby databases, ensuring zero data loss (RPO=0). This feature is marked as [Experimental] and offers two modes:

  • Max Protection Mode: Offers the highest data protection level. Transactions commit only after REDO logs are persisted on both the primary and strong sync standby. The primary stops write services if the standby is unavailable.
  • Max Availability Mode: Prioritizes cluster availability. Transactions commit when both primary and standby have persisted logs. If the standby link fails and the lag exceeds NET_TIMEOUT (default 30s), the primary automatically downgrades to async sync to restore service. It reverts to strong sync when the link recovers and lag is below HEALTH_CHECK_TIME (default 60s).

Zone-Level TableGroup (TableGroup)

A new SCOPE attribute has been added to TableGroups to control partition leader distribution:

  • SERVER: All leaders aggregate to a single node.
  • ZONE: Leaders are distributed evenly within a single Zone.
  • CLUSTER: Leaders are distributed across the cluster's PRIMARY_ZONE based on data weight.

This addresses limitations in previous versions where Sharding = None could not handle large data volumes on a single server, and Sharding = Partition/Adaptive could not control leader distribution.

Vector Search Extensions

Vector search capabilities have been expanded with new similarity functions and IVF index optimizations:

  • Functions: Added inner_product_similarity, cosine_similarity, and l2_similarity (returning values in [0,1]).
  • Query Syntax: Supports filtering results by similarity threshold using PARAMETERS (similarity=x) in LIMIT clauses.
  • IVF Index: Upgrades include parallelized Kmeans building, iterative filtering algorithms, and dynamic IVF_NPROBES configuration.

Dual Password Management

To support MySQL 8.0 compatibility and prevent connection interruptions during password rotation, OceanBase now supports dual passwords:

  • ALTER USER ... RETAIN CURRENT PASSWORD preserves the old password.
  • ALTER USER ... DISCARD OLD PASSWORD removes the old password.
  • Views like mysql.user and DBA_OB_USERS now include old_password and user_attributes fields.

Performance Optimizations

  • PL/SQL: Optimized loop scenarios, LLVM compilation artifacts, and exception handling.
  • Schema History: New objects (package, routine, UDT) are added to the recycle bin to reduce refresh performance impact.
  • External Tables: Improved Parquet page-level prefetch, CSV parallel parsing, and ODPS (MaxCompute) parallel downloads.
  • Small Transactions: Optimized state backfill to accelerate data cleanup and prevent long transactions from blocking recycling.

Breaking Changes and Behavior Updates

View Schema Changes

Several system views have new columns or semantic changes:

  • [G]V$OB_SQL_AUDIT: Added COMMIT_TIME, TX_TABLE_READ_CNT, and others. ELAPSED_TIME now includes commit time.
  • DBA_OB_USERS: Added old_password and old_password_start_time.
  • DBA_OB_TENANTS: Added PROTECTION_MODE and PROTECTION_LEVEL.
  • DBA_USERS: Added OPEN & IN ROLLOVER status.
  • DBA_SCHEDULER_JOBS: New views added to show running and scheduled jobs.

Configuration Changes

  • ob_storage_s3_url_encode_type: Default changed to compliantRfc3986Encoding.
  • schema_history_expire_time: Changed from cluster-level to tenant-level.
  • max_execution_time: New session/global variable for controlling read-only SELECT timeouts.
  • ob_vector_search_strategy: Default changed to RECALL_FIRST.

Other Behavior Changes

  • Auto Partition Split: Lowered threshold from 128MB to 1MB.
  • OBCDC: Now supports IPv6.
  • Java Objects: New OBJECT_TYPE='JAVA CLASS' added to object views.

New Syntax and Functions

  • COSINE_SIMILARITY(vector_1, vector_2), L2_SIMILARITY(vector_1, vector_2), INNER_PRODUCT_SIMILARITY(vector_1, vector_2)
  • WINDOW_FUNNEL(window, mode, timestamp, cond1, cond2, ..., condN)
  • ALTER VIEW ... COMPILE
  • ALTER TABLEGROUP ... SCOPE = 'CLUSTER'
  • MAX_EXECUTION_TIME(N) hint and session/global variable
  • CALL DBMS_VECTOR.REBUILD_INDEX(...)