Limited SQL features on TiDB X Instances
A TiDB X instance is a service-oriented TiDB Cloud offering built on the TiDB X architecture, such as a TiDB Cloud Starter, Essential, or Premium instance.
TiDB Cloud works with almost all workloads that TiDB supports, but there are some feature differences between TiDB Self-Managed and TiDB Cloud. This document describes the limitations of SQL features on TiDB Cloud Starter, Essential, and Premium. We are constantly filling in the feature gaps between TiDB Self-Managed and TiDB Cloud. If you require these features or capabilities in the gap, contact us for a feature request.
Note
This document applies only to TiDB Cloud Starter, Essential, and Premium. For TiDB Cloud Dedicated, see Limited SQL Features on TiDB Cloud Dedicated.
Statements
Placement and range management
| Statement | TiDB Cloud Premium | TiDB Cloud Starter and TiDB Cloud Essential |
|---|---|---|
ALTER PLACEMENT POLICY | Not supported 1 | Not supported 1 |
ALTER RANGE | Not supported | Not supported |
CREATE PLACEMENT POLICY | Not supported 1 | Not supported 1 |
DROP PLACEMENT POLICY | Not supported 1 | Not supported 1 |
SHOW CREATE PLACEMENT POLICY | Not supported 1 | Not supported 1 |
SHOW PLACEMENT | Not supported 1 | Not supported 1 |
SHOW PLACEMENT FOR | Not supported 1 | Not supported 1 |
SHOW PLACEMENT LABELS | Not supported 1 | Not supported 1 |
SHOW TABLE REGIONS | Supported | Not supported 1 |
SPLIT REGION | Supported | Not supported 1 |
Resource groups
| Statement | TiDB Cloud Premium | TiDB Cloud Starter and TiDB Cloud Essential |
|---|---|---|
ALTER RESOURCE GROUP | Not supported 2 | Not supported 2 |
CALIBRATE RESOURCE | Not supported 2 | Not supported 2 |
CREATE RESOURCE GROUP | Not supported 2 | Not supported 2 |
DROP RESOURCE GROUP | Not supported 2 | Not supported 2 |
SET RESOURCE GROUP | Not supported 2 | Not supported 2 |
SHOW CREATE RESOURCE GROUP | Not supported 2 | Not supported 2 |
Others
| Statement | TiDB Cloud Premium | TiDB Cloud Starter and TiDB Cloud Essential |
|---|---|---|
BACKUP | Not supported 3 | Not supported 3 |
SHOW BACKUPS | Not supported 3 | Not supported 3 |
RESTORE | Not supported 3 | Not supported 3 |
SHOW RESTORES | Not supported 3 | Not supported 3 |
BACKUP LOGS | Not supported | Not supported |
STOP BACKUP LOGS | Not supported | Not supported |
PAUSE BACKUP LOGS | Not supported | Not supported |
RESUME BACKUP LOGS | Not supported | Not supported |
SHOW BACKUP LOGS STATUS | Not supported | Not supported |
SHOW BACKUP LOGS METADATA | Not supported | Not supported |
PURGE BACKUP LOGS | Not supported | Not supported |
SHOW BR JOB | Not supported | Not supported |
SHOW BR JOB QUERY | Not supported | Not supported |
CANCEL BR JOB | Not supported | Not supported |
SHOW BACKUP META | Not supported | Not supported |
RECOVER TABLE | Not supported | Not supported |
ADMIN RESET TELEMETRY_ID | Supported | Telemetry is not supported on TiDB Cloud Starter or TiDB Cloud Essential. |
ADMIN SHOW TELEMETRY | Not supported 4 | Not supported 4 |
ADMIN SHOW SLOW | Not supported 5 | Not supported 5 |
ADMIN PLUGINS ENABLE | Not supported 8 | Not supported 8 |
ADMIN PLUGINS DISABLE | Not supported 8 | Not supported 8 |
ADMIN SET BDR ROLE | Not supported | Not supported |
ADMIN SHOW BDR ROLE | Not supported | Not supported |
ADMIN UNSET BDR ROLE | Not supported | Not supported |
ADMIN REPAIR TABLE | Not supported | Not supported |
ALTER INSTANCE | Not supported | Not supported |
ALTER INSTANCE RELOAD TLS | Not supported | TiDB Cloud Starter and TiDB Cloud Essential automatically refresh the TLS certificate. |
ALTER TABLE ... ATTRIBUTES | Not supported | Not supported |
CHANGE DRAINER | Not supported 7 | Not supported 7 |
CHANGE PUMP | Not supported 7 | Not supported 7 |
FLASHBACK CLUSTER | Not supported 3 | Not supported 3 |
IMPORT INTO | Supported, but blocks IMPORT INTO statements that use a local file path or an S3 EXTERNAL_ID. | Not supported |
LOAD DATA INFILE | Blocks LOAD DATA LOCAL INFILE from a local file path. | Only supports LOAD DATA LOCAL INFILE |
LOAD STATS | Not supported | Not supported |
SELECT ... INTO OUTFILE | Not supported 4 | Not supported 4 |
SET CONFIG | Not supported 4 | Not supported 4 |
SHOW CONFIG | Not supported 4 | Not supported 4 |
SHOW DRAINER STATUS | Not supported 7 | Not supported 7 |
SHOW PLUGINS | Not supported 8 | Not supported 8 |
SHOW PUMP STATUS | Not supported 7 | Not supported 7 |
SHUTDOWN | Not supported 4 | Not supported 4 |
PLAN REPLAYER | Supported | Supported, but uses a different file download method 11 |
time_to_live | Supported | Not supported |
Functions and operators
| Function and operator | TiDB Cloud Premium | TiDB Cloud Starter and TiDB Cloud Essential |
|---|---|---|
SLEEP | No limitation | The SLEEP() function function supports a maximum sleep time of 300 seconds. |
System tables
| Database | Table | TiDB Cloud Premium | TiDB Cloud Starter and TiDB Cloud Essential |
|---|---|---|---|
metrics_schema | All databases | Not supported | Not supported |
information_schema | ATTRIBUTES | Supported | Not supported 1 |
information_schema | CLUSTER_CONFIG | Not supported 4 | Not supported 4 |
information_schema | CLUSTER_HARDWARE | Not supported 4 | Not supported 4 |
information_schema | CLUSTER_INFO | Supported | Not supported 1 |
information_schema | CLUSTER_LOAD | Not supported 4 | Not supported 4 |
information_schema | CLUSTER_LOG | Not supported 4 | Not supported 4 |
information_schema | CLUSTER_SLOW_QUERY | Not supported 5 | Not supported 5 |
information_schema | CLUSTER_STATEMENTS_SUMMARY | Supported | Not supported 6 |
information_schema | CLUSTER_STATEMENTS_SUMMARY_EVICTED | Supported | Not supported 6 |
information_schema | CLUSTER_STATEMENTS_SUMMARY_HISTORY | Supported | Not supported 6 |
information_schema | CLUSTER_SYSTEMINFO | Not supported 4 | Not supported 4 |
information_schema | INSPECTION_RESULT | Not supported 4 | Not supported 4 |
information_schema | INSPECTION_RULES | Not supported 4 | Not supported 4 |
information_schema | INSPECTION_SUMMARY | Not supported 4 | Not supported 4 |
information_schema | METRICS_SUMMARY | Not supported 4 | Not supported 4 |
information_schema | METRICS_SUMMARY_BY_LABEL | Not supported 4 | Not supported 4 |
information_schema | METRICS_TABLES | Not supported 4 | Not supported 4 |
information_schema | PLACEMENT_POLICIES | Not supported 1 | Not supported 1 |
information_schema | RESOURCE_GROUPS | Not supported 2 | Not supported 2 |
information_schema | SLOW_QUERY | Not supported 5 | Not supported 5 |
information_schema | STATEMENTS_SUMMARY | Supported | Not supported 6 |
information_schema | STATEMENTS_SUMMARY_EVICTED | Supported | Not supported 6 |
information_schema | TIDB_HOT_REGIONS | Not supported 4 | Not supported 4 |
information_schema | TIDB_HOT_REGIONS_HISTORY | Supported | Not supported 1 |
information_schema | TIDB_SERVERS_INFO | Supported | Not supported 1 |
information_schema | TIKV_REGION_PEERS | Supported | Not supported 1 |
information_schema | TIKV_REGION_STATUS | Supported | Not supported 1 |
information_schema | TIKV_STORE_STATUS | Supported | Not supported 1 |
performance_schema | pd_profile_allocs | Not supported 4 | Not supported 4 |
performance_schema | pd_profile_block | Not supported 4 | Not supported 4 |
performance_schema | pd_profile_cpu | Not supported 4 | Not supported 4 |
performance_schema | pd_profile_goroutines | Not supported 4 | Not supported 4 |
performance_schema | pd_profile_memory | Not supported 4 | Not supported 4 |
performance_schema | pd_profile_mutex | Not supported 4 | Not supported 4 |
performance_schema | tidb_profile_allocs | Not supported 4 | Not supported 4 |
performance_schema | tidb_profile_block | Not supported 4 | Not supported 4 |
performance_schema | tidb_profile_cpu | Not supported 4 | Not supported 4 |
performance_schema | tidb_profile_goroutines | Not supported 4 | Not supported 4 |
performance_schema | tidb_profile_memory | Not supported 4 | Not supported 4 |
performance_schema | tidb_profile_mutex | Not supported 4 | Not supported 4 |
performance_schema | tikv_profile_cpu | Not supported 4 | Not supported 4 |
mysql | expr_pushdown_blacklist | Not supported 4 | Not supported 4 |
mysql | gc_delete_range | Not supported 4 | Not supported 4 |
mysql | gc_delete_range_done | Not supported 4 | Not supported 4 |
mysql | opt_rule_blacklist | Not supported 4 | Not supported 4 |
mysql | tidb | Not supported 4 | Not supported 4 |
System variables
| Variable | TiDB Cloud Premium | TiDB Cloud Starter and TiDB Cloud Essential |
|---|---|---|
hostname | Value hidden | Value hidden |
datadir | Value hidden | Not supported 1 |
ddl_slow_threshold | Read-only | Read-only |
block_encryption_mode | Read-only | Read-only |
max_connections | Read-only | Read-only |
mpp_version | Read-only | Read-only |
interactive_timeout | No limitation | Read-only 10 |
max_allowed_packet | No limitation | Read-only 10 |
plugin_dir | Not supported 8 | Not supported 8 |
plugin_load | Not supported 8 | Not supported 8 |
require_secure_transport | Not supported | Read-only 10 |
skip_name_resolve | Read-only 10 | Read-only 10 |
sql_log_bin | No limitation | Read-only 10 |
tidb_adaptive_closest_read_threshold | Not supported | Not supported |
tidb_allow_batch_cop | Read-only | Read-only |
tidb_allow_mpp | Read-only | Read-only |
tidb_analyze_skip_column_types | No limitation | Read-only 10 |
tidb_analyze_version | Read-only | Read-only |
tidb_backoff_lock_fast | Read-only | Read-only |
tidb_backoff_weight | Read-only | Read-only |
tidb_batch_commit | Not supported | Not supported |
tidb_batch_delete | Not supported | Not supported |
tidb_batch_insert | Not supported | Not supported |
tidb_capture_plan_baselines | Read-only | Read-only |
tidb_cdc_write_source | No limitation | Read-only 10 |
tidb_check_mb4_value_in_utf8 | Not supported 4 | Not supported 4 |
tidb_cloud_storage_uri | Not supported | Not supported |
tidb_config | Not supported 4 | Not supported 4 |
tidb_constraint_check_in_place | Read-only | Read-only |
tidb_constraint_check_in_place_pessimistic | Read-only | Read-only |
tidb_cost_model_version | Read-only | Read-only |
tidb_ddl_disk_quota | Read-only 10 | Read-only 10 |
tidb_ddl_enable_fast_reorg | Read-only 10 | Read-only 10 |
tidb_ddl_error_count_limit | No limitation | Read-only 10 |
tidb_ddl_flashback_concurrency | Read-only 10 | Read-only 10 |
tidb_ddl_reorg_batch_size | No limitation | Read-only 10 |
tidb_ddl_reorg_max_write_speed | Not supported | Not supported |
tidb_ddl_reorg_priority | No limitation | Read-only 10 |
tidb_ddl_reorg_worker_cnt | No limitation | Read-only 10 |
tidb_disable_txn_auto_retry | Not supported | Not supported |
tidb_dml_batch_size | Not supported | Not supported |
tidb_dml_type | Not supported | Read-only 10 |
tidb_enable_1pc | No limitation | Read-only 10 |
tidb_enable_analyze_snapshot | Read-only | Read-only |
tidb_enable_async_commit | No limitation | Read-only 10 |
tidb_enable_async_merge_global_stats | Read-only | Read-only |
tidb_enable_auto_analyze | No limitation | Read-only 10 |
tidb_enable_batch_dml | Not supported | Not supported |
tidb_enable_chunk_rpc | Read-only | Read-only |
tidb_enable_collect_execution_info | Not supported 4 | Not supported 4 |
tidb_enable_column_tracking | Not supported | Not supported |
tidb_enable_ddl | Read-only 10 | Read-only 10 |
tidb_enable_dist_task | Read-only | Read-only |
tidb_enable_exchange_partition | Not supported | Not supported |
tidb_enable_extended_stats | Read-only | Read-only |
tidb_enable_fast_analyze | Not supported | Not supported |
tidb_enable_gc_aware_memory_track | No limitation | Read-only 10 |
tidb_enable_global_index | Not supported | Not supported |
tidb_enable_gogc_tuner | Read-only 10 | Read-only 10 |
tidb_enable_historical_stats | Read-only | Read-only |
tidb_enable_historical_stats_for_capture | Read-only | Read-only |
tidb_enable_legacy_instance_scope | Read-only | Read-only |
tidb_enable_list_partition | Not supported | Not supported |
tidb_enable_local_txn | Read-only 10 | Read-only 10 |
tidb_enable_metadata_lock | Read-only | Read-only |
tidb_enable_mutation_checker | Read-only | Not supported |
tidb_enable_new_cost_interface | Read-only | Read-only |
tidb_enable_parallel_hashagg_spill | Read-only | Read-only |
tidb_enable_pipelined_window_function | No limitation | Not supported |
tidb_enable_plan_replayer_capture | Read-only | Read-only |
tidb_enable_plan_replayer_continuous_capture | Read-only | Read-only |
tidb_enable_point_get_cache | Not supported | Not supported |
tidb_enable_rate_limit_action | Read-only | Read-only |
tidb_enable_resource_control | Read-only 10 | Read-only 10 |
tidb_enable_reuse_chunk | Read-only | Read-only |
tidb_enable_slow_log | Not supported 4 | Not supported 4 |
tidb_enable_stats_owner | Read-only | Read-only |
tidb_enable_stmt_summary | Read-only 10 | Read-only 10 |
tidb_enable_table_partition | Not supported | Not supported |
tidb_enable_telemetry | Not supported 4 | Not supported 4 |
tidb_enable_tiflash_read_for_write_stmt | Not supported | Not supported |
tidb_enable_tmp_storage_on_oom | Not supported | Not supported |
tidb_enable_top_sql | Read-only 10 | Read-only 10 |
tidb_enable_tso_follower_proxy | No limitation | Read-only 10 |
tidb_enable_vectorized_expression | Read-only | Read-only |
tidb_evolve_plan_baselines | Not supported | Not supported |
tidb_evolve_plan_task_end_time | Not supported | Not supported |
tidb_evolve_plan_task_max_time | Not supported | Not supported |
tidb_evolve_plan_task_start_time | Not supported | Not supported |
tidb_expensive_query_time_threshold | Not supported 4 | Not supported 4 |
tidb_force_priority | Not supported 4 | Not supported 4 |
tidb_gc_concurrency | No limitation | Read-only 10 |
tidb_gc_enable | No limitation | Read-only 10 |
tidb_gc_leader_desc | Not supported | Not supported |
tidb_gc_max_wait_time | No limitation | Read-only 10 |
tidb_gc_run_interval | No limitation | Read-only 10 |
tidb_gc_scan_lock_mode | No limitation | Read-only 10 |
tidb_general_log | Not supported 4 | Not supported 4 |
tidb_generate_binary_plan | Read-only 10 | Read-only 10 |
tidb_gogc_tuner_threshold | No limitation | Read-only 10 |
tidb_guarantee_linearizability | Read-only 10 | Read-only 10 |
tidb_hash_exchange_with_new_collation | Read-only | Read-only |
tidb_historical_stats_duration | Not supported | Not supported |
tidb_isolation_read_engines | No limitation | Read-only 10 |
tidb_load_based_replica_read_threshold | Read-only | Read-only |
tidb_lock_unchanged_keys | Read-only | Read-only |
tidb_log_file_max_days | Read-only 10 | Read-only 10 |
tidb_mem_oom_action | Read-only | Read-only |
tidb_mem_quota_analyze | Read-only | Read-only |
tidb_memory_debug_mode_alarm_ratio | Not supported | Not supported |
tidb_memory_debug_mode_min_heap_inuse | Not supported | Not supported |
tidb_memory_usage_alarm_keep_record_num | Read-only | Read-only |
tidb_memory_usage_alarm_ratio | Not supported 4 | Not supported 4 |
tidb_merge_join_concurrency | Not supported | Not supported |
tidb_metric_query_range_duration | Not supported 4 | Not supported 4 |
tidb_metric_query_step | Not supported 4 | Not supported 4 |
tidb_non_prepared_plan_cache_size | Not supported | Not supported |
tidb_opt_broadcast_cartesian_join | Read-only | Read-only |
tidb_opt_concurrency_factor | Read-only | Read-only |
tidb_opt_copcpu_factor | Read-only | Read-only |
tidb_opt_write_row_id | Not supported 4 | Not supported 4 |
tidb_partition_prune_mode | Not supported | Not supported |
tidb_pessimistic_txn_fair_locking | Not supported | Not supported |
tidb_placement_mode | No limitation | Read-only 10 |
tidb_pprof_sql_cpu | Not supported 4 | Not supported 4 |
tidb_pre_split_regions | Read-only | Read-only |
tidb_prepared_plan_cache_size | Not supported | Read-only |
tidb_rc_read_check_ts | Read-only | Read-only |
tidb_rc_write_check_ts | Read-only | Read-only |
tidb_read_consistency | Read-only | Read-only |
tidb_record_plan_in_slow_log | Not supported 4 | Not supported 4 |
tidb_redact_log | Not supported 4 | Not supported 4 |
tidb_replica_read | Read-only 10 | Read-only 10 |
tidb_request_source_type | Not supported | Not supported |
tidb_restricted_read_only | Not supported 4 | Not supported 4 |
tidb_retry_limit | Not supported | Not supported |
tidb_row_format_version | Not supported 4 | Not supported 4 |
tidb_scatter_region | No limitation | Read-only 10 |
tidb_server_memory_limit | No limitation | Read-only 10 |
tidb_server_memory_limit_gc_trigger | No limitation | Read-only 10 |
tidb_server_memory_limit_sess_min_size | No limitation | Read-only 10 |
tidb_service_scope | Read-only | Read-only |
tidb_simplified_metrics | Read-only 10 | Read-only 10 |
tidb_skip_missing_partition_stats | Read-only | Read-only |
tidb_slow_log_threshold | Not supported 4 | Not supported 4 |
tidb_slow_query_file | Not supported 4 | Not supported 4 |
tidb_slow_txn_log_threshold | Not supported 4 | Not supported 4 |
tidb_stats_load_pseudo_timeout | Read-only | Read-only |
tidb_stats_load_sync_wait | No limitation | Read-only 10 |
tidb_stmt_summary_enable_persistent | Read-only | Read-only |
tidb_stmt_summary_file_max_backups | Read-only | Read-only |
tidb_stmt_summary_file_max_days | Read-only | Read-only |
tidb_stmt_summary_file_max_size | Read-only | Read-only |
tidb_stmt_summary_filename | Read-only | Read-only |
tidb_stmt_summary_history_size | Read-only 10 | Read-only 10 |
tidb_stmt_summary_internal_query | Read-only 10 | Read-only 10 |
tidb_stmt_summary_max_sql_length | Read-only 10 | Read-only 10 |
tidb_stmt_summary_max_stmt_count | Read-only 10 | Read-only 10 |
tidb_stmt_summary_refresh_interval | Read-only 10 | Read-only 10 |
tidb_store_limit | Read-only | Read-only |
tidb_streamagg_concurrency | Not supported | Read-only |
tidb_sysproc_scan_concurrency | No limitation | Read-only 10 |
tidb_top_sql_max_meta_count | Not supported 4 | Not supported 4 |
tidb_top_sql_max_time_series_count | Not supported 4 | Not supported 4 |
tidb_track_aggregate_memory_usage | Read-only | Read-only |
tidb_txn_assertion_level | Read-only | Read-only |
tidb_txn_commit_batch_size | Read-only | Read-only |
tidb_tso_client_batch_max_wait_time | No limitation | Read-only 10 |
tidb_ttl_delete_batch_size | No limitation | Read-only 10 |
tidb_ttl_delete_rate_limit | No limitation | Read-only 10 |
tidb_ttl_delete_worker_count | No limitation | Read-only 10 |
tidb_ttl_job_schedule_window_end_time | No limitation | Read-only 10 |
tidb_ttl_job_schedule_window_start_time | No limitation | Read-only 10 |
tidb_ttl_running_tasks | No limitation | Read-only 10 |
tidb_ttl_scan_batch_size | No limitation | Read-only 10 |
tidb_ttl_scan_worker_count | No limitation | Read-only 10 |
tidb_txn_mode | No limitation | Read-only 10 |
tidb_use_plan_baselines | Read-only | Read-only |
tidb_wait_split_region_finish | No limitation | Read-only 10 |
tidb_wait_split_region_timeout | No limitation | Read-only 10 |
tiflash_compute_dispatch_policy | Read-only | Read-only |
tiflash_replica_read | Not supported | Not supported |
tikv_client_read_timeout | Not supported | Not supported |
tx_isolation_one_shot | Not supported | Not supported |
tx_read_ts | Not supported | Not supported |
txn_scope | No limitation | Read-only 10 |
validate_password.enable | No limitation | Always enabled 9 |
validate_password.length | No limitation | At least 8 9 |
validate_password.mixed_case_count | No limitation | At least 1 9 |
validate_password.number_count | No limitation | At least 1 9 |
validate_password.policy | No limitation | Can only be MEDIUM or STRONG 9 |
validate_password.special_char_count | No limitation | At least 1 9 |
wait_timeout | No limitation | Read-only 10 |
- Configuring data placement is not supported on TiDB Cloud Starter, Essential, or Premium.↩
- Configuring resource groups is not supported on TiDB Cloud Starter, Essential, or Premium.↩
- TiDB Cloud Starter and TiDB Cloud Essential do not support downloading the file exported by
PLAN REPLAYERthrough${tidb-server-status-port}as shown in the example. Instead, TiDB Cloud Starter and TiDB Cloud Essential generate a presigned URL for you to download the file. Note that this URL remains valid for 10 hours after generation.↩ - The feature is unavailable in Security Enhanced Mode (SEM).↩
- Drainer and Pump are not supported on TiDB Cloud.↩
- Plugins are not supported on TiDB Cloud Starter, Essential, or Premium.↩
- To perform Back up and Restore operations on TiDB Cloud Starter, Essential, or Premium, you can use the TiDB Cloud console instead.↩
- To track Slow Query on TiDB Cloud Starter, Essential, or Premium, you can use the TiDB Cloud console instead.↩
- To perform Statement Analysis on TiDB Cloud Starter or TiDB Cloud Essential, you can use the TiDB Cloud console instead.↩
- The variable is read-only on TiDB Cloud Starter and TiDB Cloud Essential.↩
- TiDB Cloud Starter and TiDB Cloud Essential enforce a strong password policy.↩