> ## Documentation Index
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> Use this file to discover all available pages before exploring further.
> System table containing information about dictionaries
# system.dictionaries
**Querying in ClickHouse Cloud**
The data in this system table is held locally on each node in ClickHouse Cloud. Obtaining a complete view of all data, therefore, requires the `clusterAllReplicas` function. See [here](/reference/system-tables/overview#system-tables-in-clickhouse-cloud) for further details.
Description
Contains information about [dictionaries](/reference/statements/create/dictionary).
Columns
* `database` ([String](/reference/data-types/index)) — Name of the database containing the dictionary created by DDL query. Empty string for other dictionaries.
* `name` ([String](/reference/data-types/index)) — Dictionary name.
* `uuid` ([UUID](/reference/data-types/index)) — Dictionary UUID.
* `status` ([Enum8('NOT\_LOADED' = 0, 'LOADED' = 1, 'FAILED' = 2, 'LOADING' = 3, 'FAILED\_AND\_RELOADING' = 4, 'LOADED\_AND\_RELOADING' = 5, 'NOT\_EXIST' = 6)](/reference/data-types/index)) — Dictionary status.Possible values:
* **NOT\_LOADED** — Dictionary was not loaded because it was not used
* **LOADED** — Dictionary loaded successfully
* **FAILED** — Unable to load the dictionary as a result of an error
* **LOADING** — Dictionary is loading now
* **LOADED\_AND\_RELOADING** — Dictionary is loaded successfully
* **and is being reloaded right now (frequent reasons: SYSTEM RELOAD DICTIONARY query** —
* **timeout** —
* **dictionary config has changed)** —
* **FAILED\_AND\_RELOADING** — Could not load the dictionary as a result of an error and is loading now.
* `origin` ([String](/reference/data-types/index)) — Path to the configuration file that describes the dictionary.
* `type` ([String](/reference/data-types/index)) — Type of a dictionary allocation. Storing Dictionaries in Memory.
* `key.names` ([Array(String)](/reference/data-types/index)) — Array of key names provided by the dictionary.
* `key.types` ([Array(String)](/reference/data-types/index)) — Corresponding array of key types provided by the dictionary.
* `attribute.names` ([Array(String)](/reference/data-types/index)) — Array of attribute names provided by the dictionary.
* `attribute.types` ([Array(String)](/reference/data-types/index)) — Corresponding array of attribute types provided by the dictionary.
* `bytes_allocated` ([UInt64](/reference/data-types/index)) — Amount of RAM allocated for the dictionary.
* `hierarchical_index_bytes_allocated` ([UInt64](/reference/data-types/index)) — Amount of RAM allocated for hierarchical index.
* `query_count` ([UInt64](/reference/data-types/index)) — Number of queries since the dictionary was loaded or since the last successful reboot.
* `hit_rate` ([Float64](/reference/data-types/index)) — For cache dictionaries, the percentage of uses for which the value was in the cache.
* `found_rate` ([Float64](/reference/data-types/index)) — The percentage of uses for which the value was found.
* `element_count` ([UInt64](/reference/data-types/index)) — Number of items stored in the dictionary.
* `load_factor` ([Float64](/reference/data-types/index)) — Percentage filled in the dictionary (for a hashed dictionary, the percentage filled in the hash table).
* `source` ([String](/reference/data-types/index)) — Text describing the data source for the dictionary.
* `lifetime_min` ([UInt64](/reference/data-types/index)) — Minimum lifetime of the dictionary in memory, after which ClickHouse tries to reload the dictionary (if invalidate\_query is set, then only if it has changed). Set in seconds.
* `lifetime_max` ([UInt64](/reference/data-types/index)) — Maximum lifetime of the dictionary in memory, after which ClickHouse tries to reload the dictionary (if invalidate\_query is set, then only if it has changed). Set in seconds.
* `loading_start_time` ([DateTime](/reference/data-types/index)) — Start time for loading the dictionary.
* `last_successful_update_time` ([DateTime](/reference/data-types/index)) — End time for loading or updating the dictionary. Helps to monitor some troubles with dictionary sources and investigate the causes.
* `error_count` ([UInt64](/reference/data-types/index)) — Number of errors since last successful loading. Helps to monitor some troubles with dictionary sources and investigate the causes.
* `loading_duration` ([Float32](/reference/data-types/index)) — Duration of a dictionary loading.
* `last_exception` ([String](/reference/data-types/index)) — Text of the error that occurs when creating or reloading the dictionary if the dictionary couldn't be created.
* `comment` ([String](/reference/data-types/index)) — Text of the comment to dictionary.
Example
Configure the dictionary:
```sql theme={null}
CREATE DICTIONARY dictionary_with_comment
(
id UInt64,
value String
)
PRIMARY KEY id
SOURCE(CLICKHOUSE(HOST 'localhost' PORT tcpPort() TABLE 'source_table'))
LAYOUT(FLAT())
LIFETIME(MIN 0 MAX 1000)
COMMENT 'The temporary dictionary';
```
Make sure that the dictionary is loaded.
```sql theme={null}
SELECT * FROM system.dictionaries LIMIT 1 FORMAT Vertical;
```
```text theme={null}
Row 1:
──────
database: default
name: dictionary_with_comment
uuid: 4654d460-0d03-433a-8654-d4600d03d33a
status: NOT_LOADED
origin: 4654d460-0d03-433a-8654-d4600d03d33a
type:
key.names: ['id']
key.types: ['UInt64']
attribute.names: ['value']
attribute.types: ['String']
bytes_allocated: 0
query_count: 0
hit_rate: 0
found_rate: 0
element_count: 0
load_factor: 0
source:
lifetime_min: 0
lifetime_max: 0
loading_start_time: 1970-01-01 00:00:00
last_successful_update_time: 1970-01-01 00:00:00
loading_duration: 0
last_exception:
comment: The temporary dictionary
```