Add information about deferred filters as a separate item to EXPLAIN query output. Enable type_json_allow_duplicated_key_with_literal_and_nested_object by default to avoid errors about duplicated keys during JSON parsing. Keeper improvement: find_super_nodes command is more reliable when finding multiple super nodes by forbidding traversal of their children. Initial completion support for clickhouse-keeper-client. Flush async logging buffers in case of crash. Enable the impersonate feature by default (see EXECUTE AS target_user). Improve canceling queries with SQLite, MongoDB and MySQL table engines by KILL QUERY and cancel query (Ctrl+C). Add server setting jemalloc_profiler_sampling_rate to control jemalloc profiling. Support weights in concurrent bounded queue implementation. Add sslmode to allowed keys for PostgreSQL dictionary sources to support SSL connections. Show clear "no such file" error when passing non-existent file paths. Text indexes can now be built on Nullable and Array(Nullable) columns. Avoid dropping named collections that are dependencies of dictionary sources. Enable grace_hash join algorithm for queries with totals. Cancel background merges early in DROP DATABASE. Remove NetlinkMetricsProvider and use procfs exclusively for per-thread taskstats metric collection. Refactor Iceberg manifest file handling to fix caching issues. Optimize PREWHERE decisions for expressions like toDate(time). Add MaxAllocatedEphemeralLockSequentialNumber metric for ZooKeeper. Add new profile event KeeperRequestTotalWithSubrequests for better Keeper workload visibility. SYSTEM RELOAD DICTIONARIES now reloads dictionaries in topological order. Restart statistics cache after changing MergeTree settings. Only "alive" replicas participate in distributed index analysis. Add setting access_control_improvements.disallow_config_defined_profiles_for_sql_defined_users. Cap automatic parallel replicas heuristic to actual node count. Implement hedged requests and asynchronous reading for distributed index analysis. Deserialization of binary AggregateFunction states now requires consuming full input. Make TRUNCATE DATABASE respond to query cancellation. Improve keeper-bench with request pipelining and better stats. Support SAMPLE clause in distributed index analysis. Show chart title in dashboard even with empty results. Cap column lists in analyzer error messages to 10 entries. Return column stats from sub-queries with joins. Mark ZooKeeper session as expired immediately on finalization. Use more math functions from LLVM-libc. Reduce memory usage in system.jemalloc_profile_text. Add is_subrequest column to system.aggregated_zookeeper_log. Allow ALTER TABLE MODIFY COLUMN x TTL without specifying column type. Skip stale Keeper requests for disconnected sessions. Support text index on mapValues(map) with IN operator. Shell-like completion support in clickhouse keeper-client. Prevent Keeper mntr command from getting stuck. Reduce lock contention in Keeper dispatcher. Tolerate missing padding at the end of parquet file blocks. Fix how Alias table targets are saved as DDL dependencies. Fix wrong result or exception during reading subcolumns of ALIAS columns. Fix missing column in JOIN with non-standard identifier alias. Fix crashes in Kusto dialect functions with empty arguments. Forbid mounting local_object_storage outside user_files_path in clickhouse-client. Fix logical race in DeltaLake table engine on snapshot version change. Fix logical error on attaching a part in MergeTree with chained renames. Fix explicit settings being silently ignored when sent with compatibility. Fix client reporting NETWORK_ERROR instead of actual parsing error in INSERT with parallel parsing.
Fetched April 11, 2026