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Update partitioning-policy.md #2367

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Sep 17, 2024
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Update partitioning-policy.md #2367

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4 changes: 2 additions & 2 deletions data-explorer/kusto/management/partitioning-policy.md
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Expand Up @@ -23,11 +23,11 @@ The following are the only scenarios in which setting a data partitioning policy
* **Frequent filters on a medium or high cardinality `string` or `guid` column**:
* For example: multi-tenant solutions, or a metrics table where most or all queries filter on a column of type `string` or `guid`, such as the `TenantId` or the `MetricId`.
* Medium cardinality is at least 10,000 distinct values.
* Set the [hash partition key](#hash-partition-key) to be the `string` or `guid` column, and set the [`PartitionAssigmentMode` property](#partition-properties) to `uniform`.
* Set the [hash partition key](#hash-partition-key) to be the `string` or `guid` column, and set the [`PartitionAssignmentMode` property](#partition-properties) to `uniform`.
* **Frequent aggregations or joins on a high cardinality `string` or `guid` column**:
* For example, IoT information from many different sensors, or academic records of many different students.
* High cardinality is at least 1,000,000 distinct values, where the distribution of values in the column is approximately even.
* In this case, set the [hash partition key](#hash-partition-key) to be the column frequently grouped-by or joined-on, and set the [`PartitionAssigmentMode` property](#partition-properties) to `ByPartition`.
* In this case, set the [hash partition key](#hash-partition-key) to be the column frequently grouped-by or joined-on, and set the [`PartitionAssignmentMode` property](#partition-properties) to `ByPartition`.
* **Out-of-order data ingestion**:
* Data ingested into a table might not be ordered and partitioned into extents (shards) according to a specific `datetime` column that represents the data creation time and is commonly used to filter data. This could be due to a backfill from heterogeneous source files that include datetime values over a large time span.
* In this case, set the [uniform range datetime partition key](#uniform-range-datetime-partition-key) to be the `datetime` column.
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