This topic provides the configuration properties for source metadata policies.
{
"authTTLMs": Number,
"datasetRefreshAfterMs": Number,
"datasetExpireAfterMs": Number,
"namesRefreshMs": Number,
"datasetUpdateMode": String ["PREFETCH", "PREFETCH_QUERIED", "INLINE"]
}
| Name | Type | Description |
|---|---|---|
| authTTLMs | Number | Authorization expiry in milliseconds. |
| datasetRefreshAfterMs | Number | How often (in milliseconds) to refresh the metadata of datasets in the source. The value must be >= (greater than or equal to) 3600000 (one hour or more). |
| datasetExpireAfterMs | Number | How long (in milliseconds) to keep the metadata before it expires. The value must be >= (greater than or equal to) 3600000 (one hour or more). |
| namesRefreshMs | Number | How often (in milliseconds) to discover new datasets in the source. |
| datasetUpdateMode | String | Must be either PREFETCH, PREFETCH_QUERIED, or INLINE. |
PREFETCH - Dremio updates details for all datasets in a source.
This mode increases query performance as less work needs to be done at query time.PREFETCH_QUERIED - Dremio updates details for previously queried objects in a source.
This mode increases query performance as less work needs to be done at query time for these datasets.INLINE - Dremio updates details for a dataset at query time.
This mode minimizes metadata queries on a source when not used, but might lead to longer planning times.