VeloDB Cloud
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Database Administration
System Tables
information_schema
catalog_meta_cache_statistics

catalog_meta_cache_statistics

Overview

View the metadata cache information of the External Catalog in the currently connected FE.

Database

information_schema

Table Information

Column NameTypeDescription
CATALOG_NAMEtextThe name of the Catalog
CACHE_NAMEtextThe name of the cache
METRIC_NAMEtextThe name of the metric
METRIC_VALUEtextThe value of the metric

Usage Example

+----------------------+-----------------------------+----------------------+---------------------+
| CATALOG_NAME         | CACHE_NAME                  | METRIC_NAME          | METRIC_VALUE        |
+----------------------+-----------------------------+----------------------+---------------------+
| hive_iceberg_minio   | iceberg_table_cache         | eviction_count       | 0                   |
| hive_iceberg_minio   | iceberg_table_cache         | hit_ratio            | 0.8235294117647058  |
| hive_iceberg_minio   | iceberg_table_cache         | average_load_penalty | 5.480102048333334E8 |
| hive_iceberg_minio   | iceberg_table_cache         | estimated_size       | 6                   |
| hive_iceberg_minio   | iceberg_table_cache         | hit_count            | 28                  |
| hive_iceberg_minio   | iceberg_table_cache         | read_count           | 34                  |
| hive_iceberg_minio   | iceberg_snapshot_list_cache | eviction_count       | 0                   |
| hive_iceberg_minio   | iceberg_snapshot_list_cache | hit_ratio            | 1.0                 |
| hive_iceberg_minio   | iceberg_snapshot_list_cache | average_load_penalty | 0.0                 |
| hive_iceberg_minio   | iceberg_snapshot_list_cache | estimated_size       | 0                   |
| hive_iceberg_minio   | iceberg_snapshot_list_cache | hit_count            | 0                   |
| hive_iceberg_minio   | iceberg_snapshot_list_cache | read_count           | 0                   |
| hive_iceberg_minio   | iceberg_snapshot_cache      | eviction_count       | 0                   |
| hive_iceberg_minio   | iceberg_snapshot_cache      | hit_ratio            | 0.45454545454545453 |
| hive_iceberg_minio   | iceberg_snapshot_cache      | average_load_penalty | 5.604907246666666E8 |
| hive_iceberg_minio   | iceberg_snapshot_cache      | estimated_size       | 6                   |
| hive_iceberg_minio   | iceberg_snapshot_cache      | hit_count            | 5                   |
| hive_iceberg_minio   | iceberg_snapshot_cache      | read_count           | 11                  |

The METRIC_NAME column contains the following Caffeine cache performance metrics:

  • eviction_count: The number of entries that have been evicted from the cache
  • hit_ratio: The ratio of cache requests which were hits (ranges from 0.0 to 1.0)
  • average_load_penalty: The average time spent loading new values (in nanoseconds)
  • estimated_size: The approximate number of entries in the cache
  • hit_count: The number of times cache lookup methods have returned a cached value
  • read_count: The total number of times cache lookup methods have been called