@@ -63,27 +63,16 @@ To scan values from a specific column:
4. Click the **gear icon** in the panel for that column.
5. Click **Re-scan this field**.
## Periodically refingerprint tables
## Clearing cached values for a table or field
> Periodic refingerprinting will increase the load on your database.
To clear the [scanned field values for a table](#syncing-and-scanning-databases):
By default, Metabase only runs [fingerprinting](#how-database-fingerprinting-works) queries when you first connect your database.
1. Go to **Admin settings** > **Table Metadata**.
2. Select the database and table.
3. Click the **gear icon** in the upper right.
4. Click **Discard cached field values**.
Turn this setting ON if you want Metabase to use larger samples of column values when making suggestions in the UI:
1. Go to **Admin** > **Databases** > your database.
2. Expand **Show advanced options**.
3. Turn ON **Periodically refingerprint tables**.
## Clearing cached values
To ask Metabase to forget the data from previous [scans](#syncing-and-scanning-databases) and [fingerprinting](#how-database-fingerprinting-works):
1. Go to **Admin settings** > **Table Metadata** > your database.
2. Select the table.
3. Optional: select the column.
4. Click the **gear icon**.
5. Click **Discard cached field values**.
You can also tell Metabase to forget the cached values for individual fields by clicking the **gear** icon on a field and clicking on **Discard cached field values**.
## Disabling syncing and scanning for specific tables
...
...
@@ -109,9 +98,9 @@ A Metabase **sync** is a query that gets a list of updated table and view names,
```sql
SELECT
TRUE
FROM
FROM
"your_schema"."your_table_or_view"
WHERE
WHERE
1<>1
LIMIT0
```
...
...
@@ -142,6 +131,18 @@ A scan is more intensive than a sync query, so it only runs once during setup, a
To reduce the number of tables and fields Metabase needs to scan in order to stay current with your connected database, Metabase will only scan values for fields that someone has queried in the last fourteen days.
## Periodically refingerprint tables
> Periodic refingerprinting will increase the load on your database.
By default, Metabase only runs [fingerprinting](#how-database-fingerprinting-works) queries when you first connect your database.
Turn this setting ON if you want Metabase to use larger samples of column values when making suggestions in the UI:
1. Go to **Admin** > **Databases** > your database.
2. Expand **Show advanced options**.
3. Turn ON **Periodically refingerprint tables**.
## How database fingerprinting works
The fingerprinting query looks at the first 10,000 rows from a given table or view in your database: