Show information about Last Value Caches
Use the influxdb3 show system table command
to query and output Last Value Cache information from the last_caches system table.
influxdb3 show system \
--database DATABASE_NAME \
--token AUTH_TOKEN \
table last_cachesThis returns a table similar to the following:
| table | name | key_column_ids | key_column_names | value_column_ids | value_column_names | count | ttl |
|---|---|---|---|---|---|---|---|
| weather | weather_last | [0] | [location] | [2, 3, 4, 5, 1] | [precip, temp_avg, temp_max, temp_min, wind_avg] | 1 | 86400 |
| bitcoin | bitcoin_last | [0, 1] | [code, crypto] | [4] | [price] | 1 | 14400 |
| numbers | numbers_last | [] | [] | [0, 1] | [a, b] | 5 | 14400 |
| home | home_last | [0] | [room] | [1, 2, 3] | [temp, hum, co] | 5 | 60 |
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:
influxdb3 show system \
--database DATABASE_NAME \
--token AUTH_TOKEN \
table last_caches \
--select name,key_column_names,value_column_namesSort 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:
influxdb3 show system \
--database DATABASE_NAME \
--token AUTH_TOKEN \
table last_caches \
--order-by table,ttlResults are sorted in ascending order based on the provided columns.
In the examples above, replace the following:
DATABASE_NAME: the name of the database to query system data fromAUTH_TOKEN: your InfluxDB 3 Core 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.
GET /api/v3/query_sql
POST /api/v3/query_sql
Query all last value caches
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"
}'Query specific cache details
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"
}'Was this page helpful?
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