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Use the influxdb3 show system table command to query and output Last Value Cache information from the last_caches system table.

{{% code-placeholders "DATABASE_NAME|AUTH_TOKEN" %}}

<!-- pytest.mark.skip -->
bash
influxdb3 show system \
  --database DATABASE_NAME \
  --token AUTH_TOKEN \
  table last_caches

{{% /code-placeholders %}}

This returns a table similar to the following:

tablenamekey_column_idskey_column_namesvalue_column_idsvalue_column_namescountttl
weatherweather_last[0][location][2, 3, 4, 5, 1][precip, temp_avg, temp_max, temp_min, wind_avg]186400
bitcoinbitcoin_last[0, 1][code, crypto][4][price]114400
numbersnumbers_last[][][0, 1][a, b]514400
homehome_last[0][room][1, 2, 3][temp, hum, co]560

Query specific columns from the last_caches system table

Use the --select option to query specific columns from the last_caches system table. Provide a comma-delimited list of columns to return:

{{% code-placeholders "DATABASE_NAME|AUTH_TOKEN" %}}

<!-- pytest.mark.skip -->
bash
influxdb3 show system \
  --database DATABASE_NAME \
  --token AUTH_TOKEN \
  table last_caches \
  --select name,key_column_names,value_column_names

{{% /code-placeholders %}}

Sort last_caches system table output

Use the --order-by option to sort data from the last_caches system table by specific columns. Provide a comma-delimited list of columns to sort by:

{{% code-placeholders "DATABASE_NAME|AUTH_TOKEN" %}}

<!-- pytest.mark.skip -->
bash
influxdb3 show system \
  --database DATABASE_NAME \
  --token AUTH_TOKEN \
  table last_caches \
  --order-by table,ttl

{{% /code-placeholders %}}

[!Note] Results are sorted in ascending order based on the provided columns.

In the examples above, replace the following:

  • {{% code-placeholder-key %}}DATABASE_NAME{{% /code-placeholder-key %}}: the name of the database to query system data from
  • {{% code-placeholder-key %}}AUTH_TOKEN{{% /code-placeholder-key %}}: your {{< product-name >}} {{% show-in "enterprise" %}}admin {{% /show-in %}} authentication token

Use the HTTP API

To use the HTTP API to query and output cache information from the system table, send a GET or POST request to the /api/v3/query_sql endpoint.

{{% api-endpoint method="GET" endpoint="/api/v3/query_sql" api-ref="/influxdb3/version/api/v3/#operation/GetExecuteQuerySQL" %}}

{{% api-endpoint method="POST" endpoint="/api/v3/query_sql" api-ref="/influxdb3/version/api/v3/#operation/PostExecuteQuerySQL" %}}

Query all last value caches

{{% code-placeholders "DATABASE_NAME|AUTH_TOKEN" %}}

bash
curl -X POST "https://localhost:8181/api/v3/query_sql" \
  --header "Authorization: Bearer AUTH_TOKEN" \
  --json '{
    "db": "DATABASE_NAME",
    "q": "SELECT * FROM system.last_caches",
    "format": "json"
  }'

{{% /code-placeholders %}}

Query specific cache details

{{% code-placeholders "DATABASE_NAME|AUTH_TOKEN|CACHE_NAME" %}}

bash
curl -X POST "https://localhost:8181/api/v3/query_sql" \
  --header "Authorization: Bearer AUTH_TOKEN" \
  --json '{
    "db": "DATABASE_NAME",
    "q": "SELECT * FROM system.last_caches WHERE name = '\''CACHE_NAME'\''",
    "format": "json"
  }'

{{% /code-placeholders %}}