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SHOW [GLOBAL|SESSION] VARIABLES

This statement shows a list of variables for the scope of either GLOBAL or SESSION. If no scope is specified, the default scope of SESSION will apply.

Synopsis

ShowStmt:

ShowStmt

ShowTargetFilterable:

ShowTargetFilterable

GlobalScope:

GlobalScope

Examples

List all TiDB specific variables. For detailed description, refer to System Variables.

mysql> SHOW GLOBAL VARIABLES LIKE 'tidb%'; +-------------------------------------+---------------------+ | Variable_name | Value | +-------------------------------------+---------------------+ | tidb_allow_batch_cop | 0 | | tidb_allow_remove_auto_inc | 0 | | tidb_auto_analyze_end_time | 23:59 +0000 | | tidb_auto_analyze_ratio | 0.5 | | tidb_auto_analyze_start_time | 00:00 +0000 | | tidb_backoff_lock_fast | 100 | | tidb_backoff_weight | 2 | | tidb_batch_commit | 0 | | tidb_batch_delete | 0 | | tidb_build_stats_concurrency | 4 | | tidb_capture_plan_baselines | off | | tidb_check_mb4_value_in_utf8 | 1 | | tidb_checksum_table_concurrency | 4 | | tidb_config | | | tidb_constraint_check_in_place | 0 | | tidb_current_ts | 0 | | tidb_ddl_error_count_limit | 512 | | tidb_ddl_reorg_batch_size | 256 | | tidb_ddl_reorg_priority | PRIORITY_LOW | | tidb_ddl_reorg_worker_cnt | 4 | | tidb_disable_txn_auto_retry | 1 | | tidb_distsql_scan_concurrency | 15 | | tidb_dml_batch_size | 20000 | | tidb_enable_cascades_planner | 0 | | tidb_enable_chunk_rpc | 1 | | tidb_enable_collect_execution_info | 1 | | tidb_enable_fast_analyze | 0 | | tidb_enable_index_merge | 0 | | tidb_enable_noop_functions | 0 | | tidb_enable_radix_join | 0 | | tidb_enable_slow_log | 1 | | tidb_enable_stmt_summary | 1 | | tidb_enable_table_partition | on | | tidb_enable_vectorized_expression | 1 | | tidb_enable_window_function | 1 | | tidb_evolve_plan_baselines | off | | tidb_evolve_plan_task_end_time | 23:59 +0000 | | tidb_evolve_plan_task_max_time | 600 | | tidb_evolve_plan_task_start_time | 00:00 +0000 | | tidb_expensive_query_time_threshold | 60 | | tidb_force_priority | NO_PRIORITY | | tidb_general_log | 0 | | tidb_hash_join_concurrency | 5 | | tidb_hashagg_final_concurrency | 4 | | tidb_hashagg_partial_concurrency | 4 | | tidb_index_join_batch_size | 25000 | | tidb_index_lookup_concurrency | 4 | | tidb_index_lookup_join_concurrency | 4 | | tidb_index_lookup_size | 20000 | | tidb_index_serial_scan_concurrency | 1 | | tidb_init_chunk_size | 32 | | tidb_isolation_read_engines | tikv, tiflash, tidb | | tidb_low_resolution_tso | 0 | | tidb_max_chunk_size | 1024 | | tidb_max_delta_schema_count | 1024 | | tidb_mem_quota_hashjoin | 34359738368 | | tidb_mem_quota_indexlookupjoin | 34359738368 | | tidb_mem_quota_indexlookupreader | 34359738368 | | tidb_mem_quota_mergejoin | 34359738368 | | tidb_mem_quota_nestedloopapply | 34359738368 | | tidb_mem_quota_query | 1073741824 | | tidb_mem_quota_sort | 34359738368 | | tidb_mem_quota_topn | 34359738368 | | tidb_metric_query_range_duration | 60 | | tidb_metric_query_step | 60 | | tidb_opt_agg_push_down | 0 | | tidb_opt_concurrency_factor | 3 | | tidb_opt_copcpu_factor | 3 | | tidb_opt_correlation_exp_factor | 1 | | tidb_opt_correlation_threshold | 0.9 | | tidb_opt_cpu_factor | 3 | | tidb_opt_desc_factor | 3 | | tidb_opt_disk_factor | 1.5 | | tidb_opt_distinct_agg_push_down | 0 | | tidb_opt_insubq_to_join_and_agg | 1 | | tidb_opt_join_reorder_threshold | 0 | | tidb_opt_memory_factor | 0.001 | | tidb_opt_network_factor | 1 | | tidb_opt_scan_factor | 1.5 | | tidb_opt_seek_factor | 20 | | tidb_opt_write_row_id | 0 | | tidb_optimizer_selectivity_level | 0 | | tidb_pprof_sql_cpu | 0 | | tidb_projection_concurrency | 4 | | tidb_query_log_max_len | 4096 | | tidb_record_plan_in_slow_log | 1 | | tidb_replica_read | leader | | tidb_retry_limit | 10 | | tidb_row_format_version | 2 | | tidb_scatter_region | 0 | | tidb_skip_isolation_level_check | 0 | | tidb_skip_utf8_check | 0 | | tidb_slow_log_threshold | 300 | | tidb_slow_query_file | tidb-slow.log | | tidb_snapshot | | | tidb_stmt_summary_history_size | 24 | | tidb_stmt_summary_internal_query | 0 | | tidb_stmt_summary_max_sql_length | 4096 | | tidb_stmt_summary_max_stmt_count | 3000 | | tidb_stmt_summary_refresh_interval | 1800 | | tidb_store_limit | 0 | | tidb_txn_mode | | | tidb_use_plan_baselines | on | | tidb_wait_split_region_finish | 1 | | tidb_wait_split_region_timeout | 300 | | tidb_window_concurrency | 4 | +-------------------------------------+---------------------+ 108 rows in set (0.01 sec) mysql> SHOW GLOBAL VARIABLES LIKE 'time_zone%'; +---------------+--------+ | Variable_name | Value | +---------------+--------+ | time_zone | SYSTEM | +---------------+--------+ 1 row in set (0.00 sec)

MySQL compatibility

This statement is understood to be fully compatible with MySQL. Any compatibility differences should be reported via an issue on GitHub.

See also

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