> ## Documentation Index > Fetch the complete documentation index at: https://private-7c7dfe99-fix-nav-issues.mintlify.site/llms.txt > Use this file to discover all available pages before exploring further. > 介绍什么是系统表及其用途。 # 系统表 {/*AUTOGENERATED_START*/} | 页面 | 说明 | | ------------------------------------------------------------------------------------------------------ | --------------------------------------------------------------------------------------------------------------------------------------------------------------- | | [System Tables Overview](/zh/reference/system-tables/overview) | Overview of what system tables are and why they are useful. | | [system.histogram\_metric\_log](/zh/reference/system-tables/histogram_metric_log) | System table containing periodic snapshots of histogram metrics, flushed to disk. | | [INFORMATION\_SCHEMA](/zh/reference/system-tables/information_schema) | System database providing an almost standardized DBMS-agnostic view on metadata of database objects. | | [system.aggregate\_function\_combinators](/zh/reference/system-tables/aggregate_function_combinators) | Contains a list of all available aggregate function combinators, which could be applied to aggregate functions and change the way they work. | | [system.aggregated\_zookeeper\_log](/zh/reference/system-tables/aggregated_zookeeper_log) | System table containing aggregated statistics of ZooKeeper operations grouped by session, path, operation type, component, and subrequest flag. | | [system.asynchronous\_insert\_log](/zh/reference/system-tables/asynchronous_insert_log) | System table containing information about async inserts. Each entry represents an insert query buffered into an async insert query. | | [system.asynchronous\_loader](/zh/reference/system-tables/asynchronous_loader) | System table containing information about and status of recent asynchronous jobs (e.g. for tables which are loading). The table contains a row for every job. | | [system.asynchronous\_metric\_log](/zh/reference/system-tables/asynchronous_metric_log) | System table containing historical values for `system.asynchronous_metrics`, which are saved once per time interval (one second by default) | | [system.asynchronous\_inserts](/zh/reference/system-tables/asynchronous_inserts) | System table containing information about pending asynchronous inserts in queue. | | [system.asynchronous\_metrics](/zh/reference/system-tables/asynchronous_metrics) | System table containing metrics that are calculated periodically in the background. For example, the amount of RAM in use. | | [system.azure\_queue\_settings](/zh/reference/system-tables/azure_queue_settings) | System table containing information about settings of AzureQueue tables. Available from server version `24.10`. | | [system.azure\_queue\_metadata\_cache](/zh/reference/system-tables/azure_queue_metadata_cache) | Contains in-memory state of AzureQueue metadata and currently processed rows per file. | | [system.azure\_queue\_log](/zh/reference/system-tables/azure_queue_log) | Contains log entries with information about files processed by the AzureQueue engine. | | It is safe to truncate or drop this table at any time. | | | [system.background\_schedule\_pool\_log](/zh/reference/system-tables/background_schedule_pool_log) | System table containing history of background schedule pool task executions. | | [system.background\_schedule\_pool](/zh/reference/system-tables/background_schedule_pool) | System table containing information about tasks in background schedule pools. | | [system.backup\_log](/zh/reference/system-tables/backup_log) | System table containing logging entries with information about `BACKUP` and `RESTORE` operations. | | [system.backups](/zh/reference/system-tables/backups) | System table containing logging entries with information about `BACKUP` and `RESTORE` operations. | | [system.blob\_storage\_log](/zh/reference/system-tables/blob_storage_log) | System table containing logging entries with information about various blob storage operations such as uploads and deletes. | | [system.build\_options](/zh/reference/system-tables/build_options) | System table containing information about ClickHouse server's build options. | | [system.certificates](/zh/reference/system-tables/certificates) | Contains information about available certificates and their sources. | | [system.clusters](/zh/reference/system-tables/clusters) | System table containing information about clusters available in the config file and the servers defined in them. | | [system.codecs](/zh/reference/system-tables/codecs) | System table containing information about codecs in queue. | | [system.collations](/zh/reference/system-tables/collations) | Contains a list of all available collations for alphabetical comparison of strings. | | [system.columns](/zh/reference/system-tables/columns) | System table containing information about columns in all tables | | [system.completions](/zh/reference/system-tables/completions) | Contains a list of completion tokens. | | [system.contributors](/zh/reference/system-tables/contributors) | System table containing information about contributors. | | [system.crash\_log](/zh/reference/system-tables/crash_log) | System table containing information about stack traces for fatal errors. | | [system.current\_roles](/zh/reference/system-tables/current_roles) | System table containing active roles for the current user. | | [system.dashboards](/zh/reference/system-tables/dashboards) | Contains queries used by `/dashboard` page accessible though the HTTP interface. useful for monitoring and troubleshooting. | | [system.data\_skipping\_indices](/zh/reference/system-tables/data_skipping_indices) | System table containing information about existing data skipping indices in all the tables. | | [system.data\_type\_families](/zh/reference/system-tables/data_type_families) | System table containing information about supported data types | | [system.database\_engines](/zh/reference/system-tables/database_engines) | System table containing a list of database engines supported by the server. | | [system.database\_replicas](/zh/reference/system-tables/database_replicas) | System table containing information about and status of replicated database. | | [system.databases](/zh/reference/system-tables/databases) | System table containing information about the databases that are available to the current user. | | [system.dead\_letter\_queue](/zh/reference/system-tables/dead_letter_queue) | System table containing information about messages received via a streaming engine and parsed with errors. | | [system.delta\_lake\_metadata\_log](/zh/reference/system-tables/delta_metadata_log) | System table containing information about metadata files read from Delta Lake tables. Each entry represents a root metadata JSON file. | | [system.detached\_parts](/zh/reference/system-tables/detached_parts) | System table containing information about detached parts of MergeTree tables | | [system.detached\_tables](/zh/reference/system-tables/detached_tables) | System table containing information about each detached table. | | [system.dictionaries](/zh/reference/system-tables/dictionaries) | System table containing information about dictionaries | | [system.dimensional\_metrics](/zh/reference/system-tables/dimensional_metrics) | This table contains dimensional metrics that can be calculated instantly and exported in the Prometheus format. It is always up to date. | | [system.disks](/zh/reference/system-tables/disks) | System table containing information about disks defined in the server configuration | | [system.distributed\_ddl\_queue](/zh/reference/system-tables/distributed_ddl_queue) | System table containing information about distributed ddl queries (queries using the ON CLUSTER clause) that were executed on a cluster. | | [system.distribution\_queue](/zh/reference/system-tables/distribution_queue) | System table containing information about local files that are in the queue to be sent to the shards. | | [system.dns\_cache](/zh/reference/system-tables/dns_cache) | System table containing information about cached DNS records. | | [system.dropped\_tables](/zh/reference/system-tables/dropped_tables) | System table containing information about tables that drop table has been executed on but for which data cleanup has not yet been performed | | [system.dropped\_tables\_parts](/zh/reference/system-tables/dropped_tables_parts) | System table containing information about parts of MergeTree dropped tables from `system.dropped_tables` | | [system.enabled\_roles](/zh/reference/system-tables/enabled_roles) | System table containing all active roles at the moment, including the current role of the current user and the granted roles for the current role | | [system.error\_log](/zh/reference/system-tables/error_log) | System table containing the history of error values from table `system.errors`, periodically flushed to disk. | | [system.errors](/zh/reference/system-tables/errors) | System table containing error codes with the number of times they have been triggered. | | [system.events](/zh/reference/system-tables/events) | System table containing information about the number of events that have occurred in the system. | | [system.fail\_points](/zh/reference/system-tables/fail_points) | Contains a list of all available failpoints with their type and current status. | | [system.filesystem\_cache\_settings](/zh/reference/system-tables/filesystem_cache_settings) | Contains information about all filesystem cache settings | | [system.filesystem\_read\_prefetches\_log](/zh/reference/system-tables/filesystem_read_prefetches_log) | Contains a history of all prefetches done during reading from MergeTree tables backed by a remote filesystem. | | It is safe to truncate or drop this table at any time. | | | [system.filesystem\_cache\_log](/zh/reference/system-tables/filesystem_cache_log) | Contains a history of all events occurred with filesystem cache for objects on a remote filesystem. | | It is safe to truncate or drop this table at any time. | | | [system.filesystem\_cache](/zh/reference/system-tables/filesystem_cache) | Contains information about all entries inside filesystem cache for remote objects. | | [system.formats](/zh/reference/system-tables/formats) | Contains a list of all the formats along with flags whether a format is suitable for input/output or whether it supports parallelization. | | [system.functions](/zh/reference/system-tables/functions) | System table containing information about normal and aggregate functions. | | [system.grants](/zh/reference/system-tables/grants) | 显示已向 ClickHouse 用户账户授予哪些权限的系统表。 | | [system.graphite\_retentions](/zh/reference/system-tables/graphite_retentions) | 包含参数 `graphite_rollup` 信息的系统表，这些参数用于使用 `GraphiteMergeTree` 类型引擎的表。 | | [system.histogram\_metrics](/zh/reference/system-tables/histogram_metrics) | 此表包含可即时计算并以 Prometheus 格式导出的直方图指标，且始终为最新数据。 | | [system.iceberg\_history](/zh/reference/system-tables/iceberg_history) | Iceberg 快照历史的系统表 | | [system.iceberg\_metadata\_log](/zh/reference/system-tables/iceberg_metadata_log) | 包含从 Iceberg 表读取的元数据文件信息的系统表。每个条目表示根元数据文件、从 Avro 文件中提取的元数据，或某个 Avro 文件中的一个条目。 | | [system.instrumentation](/zh/reference/system-tables/instrumentation) | 包含插桩点信息的系统表 | | [system.jemalloc\_stats](/zh/reference/system-tables/jemalloc_stats) | 以单行单列返回 jemalloc 统计信息。等同于 SYSTEM JEMALLOC STATS 命令。 | | [system.jemalloc\_bins](/zh/reference/system-tables/jemalloc_bins) | 包含 jemalloc allocator 在不同大小类 (bins) 中的内存分配信息的系统表，这些信息聚合自所有 arena。 | | [system.jemalloc\_profile\_text](/zh/reference/system-tables/jemalloc_profile_text) | 显示已符号化的 jemalloc 堆内存剖析。请先运行 'SYSTEM JEMALLOC FLUSH PROFILE' 生成 profile。 | | [system.kafka\_consumers](/zh/reference/system-tables/kafka_consumers) | 包含 Kafka 消费者信息的系统表。 | | [system.keywords](/zh/reference/system-tables/keywords) | 包含 ClickHouse 解析器所使用的全部关键字列表。 | | [system.licenses](/zh/reference/system-tables/licenses) | 包含位于 ClickHouse 源码 contrib 目录中的第三方库许可证信息的系统表。 | | [system.macros](/zh/reference/system-tables/macros) | 包含服务器配置中定义的所有宏列表。 | | [system.masking\_policies](/zh/reference/system-tables/masking_policies) | 包含系统中所有脱敏策略信息的系统表。 | | [system.merge\_tree\_settings](/zh/reference/system-tables/merge_tree_settings) | 包含 MergeTree 表设置相关信息的系统表。 | | [system.merges](/zh/reference/system-tables/merges) | 包含 MergeTree 家族中的表当前正在进行的合并和 part mutation 信息的系统表。 | | [system.metric\_log](/zh/reference/system-tables/metric_log) | 包含表 `system.metrics` 和 `system.events` 中指标值历史记录的系统表，并会定期写入磁盘。 | | [system.metrics](/zh/reference/system-tables/metrics) | 包含可即时计算或具有当前值的指标的系统表。 | | [system.models](/zh/reference/system-tables/models) | 包含已加载到 LibraryBridge 内存中的 CatBoost 模型列表及其加载时间。 | | [system.moves](/zh/reference/system-tables/moves) | 包含 MergeTree 表中正在进行的数据分区片段移动信息的系统表。每次数据分区片段移动对应一行。 | | [system.mutations](/zh/reference/system-tables/mutations) | 包含 MergeTree 表的变更及其进度信息的系统表。每条变更命令对应一行。 | | [system.named\_collections](/zh/reference/system-tables/named_collections) | 包含所有通过 SQL 查询创建或从配置文件中解析出的 named collections 列表。 | | [system.numbers\_mt](/zh/reference/system-tables/numbers_mt) | 与 `system.numbers` 类似的系统表，但读取是并行的，返回的数字顺序可能任意。 | | [system.numbers](/zh/reference/system-tables/numbers) | 包含一个名为 `number` 的 UInt64 列的系统表，该列包含从零开始的几乎所有自然数。 | | [system.one](/zh/reference/system-tables/one) | 包含单行且只有一个值为 0 的 `dummy` UInt8 列的系统表。类似于其他 DBMS 中的 `DUAL` 表。 | | [system.opentelemetry\_span\_log](/zh/reference/system-tables/opentelemetry_span_log) | 包含已执行查询的 trace span 信息的系统表。 | | [system.part\_moves\_between\_shards](/zh/reference/system-tables/part_moves_between_shards) | 包含当前正在分片之间移动的 parts 及其进度信息。 | | [system.part\_log](/zh/reference/system-tables/part_log) | 包含 MergeTree 家族中的表中与数据分区片段相关事件信息的系统表，例如数据的添加或合并。 | | [system.parts](/zh/reference/system-tables/parts) | 包含 MergeTree 的 parts 信息的系统表 | | [system.parts\_columns](/zh/reference/system-tables/parts_columns) | 包含 MergeTree 表的 parts 和列信息的系统表。 | | [system.predicate\_statistics\_log](/zh/reference/system-tables/predicate_statistics_log) | 包含在查询执行期间从 `MergeTree` 读取管道中采样收集的过滤器和索引选择性统计信息的系统表。 | | [system.primes](/zh/reference/system-tables/primes) | 包含一个名为 `prime` 的 UInt64 列的系统表，该列按升序存储质数，从 2 开始。 | | [system.privileges](/zh/reference/system-tables/privileges) | 包含可授予用户或角色的所有可用权限列表。 | | [system.processes](/zh/reference/system-tables/processes) | 用于实现 `SHOW PROCESSLIST` 查询的系统表。 | | [system.processors\_profile\_log](/zh/reference/system-tables/processors_profile_log) | 包含处理器级别分析信息的系统表 (可在 `EXPLAIN PIPELINE` 中查看) 。 | | [system.projection\_parts\_columns](/zh/reference/system-tables/projection_parts_columns) | 包含 MergeTree 家族表中投影 parts 的列信息的系统表。 | | [system.projection\_parts](/zh/reference/system-tables/projection_parts) | 包含 MergeTree 家族表中投影 parts 信息的系统表。 | | [system.projections](/zh/reference/system-tables/projections) | 包含所有表中现有投影信息的系统表。 | | [system.query\_views\_log](/zh/reference/system-tables/query_views_log) | 包含运行查询时所执行依赖视图信息的系统表，例如视图类型或执行时间。 | | [system.query\_condition\_cache](/zh/reference/system-tables/query_condition_cache) | 显示查询条件缓存内容的系统表。 | | [system.query\_thread\_log](/zh/reference/system-tables/query_thread_log) | 包含执行查询的线程信息的系统表，例如线程名称、线程开始时间以及查询处理耗时。 | | [system.query\_metric\_log](/zh/reference/system-tables/query_metric_log) | 包含各个查询对应的 `system.events` 表中的内存和指标值历史记录的系统表，这些记录会定期写入磁盘。 | | [system.query\_log](/zh/reference/system-tables/query_log) | 包含已执行查询信息的系统表，例如开始时间、处理耗时和错误消息。 | | [system.query\_cache](/zh/reference/system-tables/query_cache) | 显示查询缓存内容的系统表。 | | [system.quota\_usage](/zh/reference/system-tables/quota_usage) | 包含当前用户配额使用情况信息的系统表，例如已使用多少配额以及剩余多少。 | | [system.quota\_limits](/zh/reference/system-tables/quota_limits) | 包含所有 quotas 在各个时间区间内最大值信息的系统表。一个 quota 可以对应任意数量的行，也可以不对应任何行。 | | [system.quotas\_usage](/zh/reference/system-tables/quotas_usage) | 包含所有用户配额使用情况信息的系统表。 | | [system.quotas](/zh/reference/system-tables/quotas) | 包含 quotas 信息的系统表。 | | [system.remote\_data\_paths](/zh/reference/system-tables/remote_data_paths) | 包含存储在远程磁盘 (如 S3 或 Azure Blob 存储) 上的数据文件信息的系统表。 | | [system.replicas](/zh/reference/system-tables/replicas) | 包含本地服务器上复制表的信息和状态的系统表，可用于监控。 | | [system.replicated\_merge\_tree\_settings](/zh/reference/system-tables/replicated_merge_tree_settings) | 包含所有 ReplicatedMergeTree 专有设置及其当前值、默认值和说明的列表。你可以在 CREATE 查询的 SETTINGS 部分更改其中任意一项。 | | [system.replicated\_fetches](/zh/reference/system-tables/replicated_fetches) | 包含当前正在运行的后台拉取操作信息的系统表。 | | [system.replication\_queue](/zh/reference/system-tables/replication_queue) | 包含 `ReplicatedMergeTree` 家族表在 ClickHouse Keeper 或 ZooKeeper 中存储的复制队列任务信息的系统表。 | | [system.resources](/zh/reference/system-tables/resources) | 包含本地服务器上资源信息的系统表，每个资源对应一行。 | | [system.rocksdb](/zh/reference/system-tables/rocksdb) | 包含嵌入式 RocksDB 导出的指标列表。 | | [system.role\_grants](/zh/reference/system-tables/role_grants) | 包含用户和角色的角色授权信息的系统表。 | | [system.roles](/zh/reference/system-tables/roles) | 包含已配置角色信息的系统表。 | | [system.row\_policies](/zh/reference/system-tables/row_policies) | 包含某个特定表的过滤器，以及应使用此 ROW POLICY 的角色和/或用户列表的系统表。 | | [system.s3\_queue\_settings](/zh/reference/system-tables/s3_queue_settings) | 包含 S3Queue 表设置信息的系统表。自服务器版本 `24.10` 起可用。 | | [system.s3queue\_metadata\_cache](/zh/reference/system-tables/s3queue_metadata_cache) | 包含 S3Queue 元数据的内存状态，以及每个文件当前正在处理的行。 | | [system.s3queue\_log](/zh/reference/system-tables/s3queue_log) | Contains log entries with information about files processed by the S3Queue engine. | | It is safe to truncate or drop this table at any time. | | | [system.scheduler](/zh/reference/system-tables/scheduler) | System table containing information about and status of scheduling nodes residing on the local server. | | [system.schema\_inference\_cache](/zh/reference/system-tables/schema_inference_cache) | System table containing information about all cached file schemas. | | [system.server\_settings](/zh/reference/system-tables/server_settings) | System table containing formation about global settings for the server, which are specified in `config.xml`. | | [system.session\_log](/zh/reference/system-tables/session_log) | System table containing information about all successful and failed login and logout events. | | [system.settings](/zh/reference/system-tables/settings) | System table containing information about session settings for current user. | | [system.settings\_profile\_elements](/zh/reference/system-tables/settings_profile_elements) | System table which describes the content of the settings profile: constraints, roles and users that the setting applies to, parent settings profiles. | | [system.settings\_changes](/zh/reference/system-tables/settings_changes) | System table containing information about setting changes in previous ClickHouse versions. | | [system.settings\_profiles](/zh/reference/system-tables/settings_profiles) | System table which contains properties of configured setting profiles. | | [system.stack\_trace](/zh/reference/system-tables/stack_trace) | System table which contains stack traces of all server threads. Allows developers to introspect the server state. | | [system.storage\_policies](/zh/reference/system-tables/storage_policies) | System table containing information about storage policies and volumes which are defined in server configuration. | | [system.symbols](/zh/reference/system-tables/symbols) | System table useful for C++ experts and ClickHouse engineers containing information for introspection of the `clickhouse` binary. | | [system.table\_engines](/zh/reference/system-tables/table_engines) | System table containing descriptions of table engines supported by the server and the features they support. | | [system.table\_functions](/zh/reference/system-tables/table_functions) | Contains a list of all available table functions with their descriptions. | | [system.tables](/zh/reference/system-tables/tables) | System table containing metadata of each table that the server knows about. | | [system.text\_log](/zh/reference/system-tables/text_log) | System table containing logging entries. | | [system.time\_zones](/zh/reference/system-tables/time_zones) | System table containing a list of time zones that are supported by the ClickHouse server. | | [system.tokenizers](/zh/reference/system-tables/tokenizers) | System table which shows all available tokenizers. | | [system.trace\_log](/zh/reference/system-tables/trace_log) | System table containing stack traces collected by the sampling query profiler. | | [system.transactions](/zh/reference/system-tables/transactions) | Contains a list of transactions and their state. | | [system.transactions\_info\_log](/zh/reference/system-tables/transactions_info_log) | Contains information about all transactions executed on a current server. | | It is safe to truncate or drop this table at any time. | | | [system.unicode](/zh/reference/system-tables/unicode) | System table containing a list of Unicode characters and their properties. | | [system.user\_processes](/zh/reference/system-tables/user_processes) | System table containing information useful for an overview of memory usage and ProfileEvents of users. | | [system.user\_directories](/zh/reference/system-tables/user_directories) | Contains the information about configured user directories - directories on the file system from which ClickHouse server is allowed to read user provided data. | | [system.user\_defined\_functions](/zh/reference/system-tables/user_defined_functions) | System table containing loading status and configuration metadata for User-Defined Functions (UDFs). | | [system.users](/zh/reference/system-tables/users) | System table containing a list of user accounts configured on the server. | | [system.view\_refreshes](/zh/reference/system-tables/view_refreshes) | System table containing information about Refreshable Materialized Views. | | [system.warnings](/zh/reference/system-tables/system_warnings) | This table contains warning messages about clickhouse server. | | [system.warnings](/zh/reference/system-tables/warnings) | 包含有关服务器配置的警告，clickhouse-client 在连接到服务器后会立即显示这些警告。 | | [system.workloads](/zh/reference/system-tables/workloads) | 包含本地服务器上 workloads 信息的系统表。 | | [system.zeros](/zh/reference/system-tables/zeros) | 生成无限数量的非物化零值。 | | [system.zeros\_mt](/zh/reference/system-tables/zeros_mt) | system.zeros 的多线程版本。 | | [system.zookeeper\_watches](/zh/reference/system-tables/zookeeper_watches) | 显示此 ClickHouse 服务器当前已注册且处于活动状态的 ZooKeeper watches 的系统表。 | | [system.zookeeper\_info](/zh/reference/system-tables/zookeeper_info) | 输出所有可用 Keeper 节点内部信息的系统表。 | | [system.zookeeper\_log](/zh/reference/system-tables/zookeeper_log) | 包含发送到 ZooKeeper 服务器的请求参数及其响应信息的系统表。 | | [system.zookeeper\_connection](/zh/reference/system-tables/zookeeper_connection) | 仅在配置了 ZooKeeper 时存在的系统表。显示当前与 ZooKeeper 的连接 (包括辅助 ZooKeepers) 。 | | [system.zookeeper\_connection\_log](/zh/reference/system-tables/zookeeper_connection_log) | 显示 ZooKeeper 连接历史 (包括辅助 ZooKeepers) 。 | | [system.zookeeper](/zh/reference/system-tables/zookeeper) | 仅在配置了 ClickHouse Keeper 或 ZooKeeper 时存在的系统表。它暴露配置中定义的 Keeper 集群中的数据。 |