Adjusted schedule_interval of compression policy

This PR updates the documentation regarding the changed default value of the schedule_interval parameter of the compression_policy (see timescale/timescaledb#6102).

api/add_compression_policy.md

@@ -29,7 +29,7 @@ see [informational views][informational-views].
 |-|-|-|
 |`hypertable`|REGCLASS|Name of the hypertable or continuous aggregate|
 |`compress_after`|INTERVAL or INTEGER|The age after which the policy job compresses chunks. `compress_after` is calculated relative to the current time, so chunks containing data older than `now - {compress_after}::interval` are compressed.|
-|`schedule_interval`|INTERVAL|The interval between the finish time of the last execution and the next start. Defaults to NULL.|
+|`schedule_interval`|INTERVAL|The interval between the finish time of the last execution and the next start. Defaults to 12 hours for hyper tables with a `chunk_time_interval` >= 1 day and `chunk_time_interval / 2` for all other hypertables.|
 |`initial_start`|TIMESTAMPTZ|Time the policy is first run. Defaults to NULL. If omitted, then the schedule interval is the interval from the finish time of the last execution to the next start. If provided, it serves as the origin with respect to which the next_start is calculated |
 |`timezone`|TEXT|A valid time zone. If `initial_start` is also specified, subsequent executions of the compression policy are aligned on its initial start. However, daylight savings time (DST) changes may shift this alignment. Set to a valid time zone if this is an issue you want to mitigate. If omitted, UTC bucketing is performed. Defaults to `NULL`.|