.alter database policy merge command

  • Article
  • 09/30/2024

Applies to: ✅ Azure Data Explorer

Changes the database's merge policy. The merge policy defines if and how extents (Data Shards) should get merged.

Permissions

You must have at least Database Admin permissions to run this command.

Syntax

.alter database DatabaseName policy merge PolicyObject

Learn more about syntax conventions.

Parameters

Name Type Required Description
DatabaseName string ✔️ The name of the database for which to alter the merge policy.
PolicyObject string ✔️ A policy object that defines the merge policy. For more information, see merge policy.

Examples

Set all properties of the policy explicitly, at the database level:

.alter database [database_name] policy merge ```
{
  "RowCountUpperBoundForMerge": 16000000,
  "OriginalSizeMBUpperBoundForMerge": 0,
  "MaxExtentsToMerge": 100,
  "LoopPeriod": "01:00:00",
  "MaxRangeInHours": 24,
  "AllowRebuild": true,
  "AllowMerge": true,
  "Lookback": {
    "Kind": "Default"
  }
}```

Set the default merge policy at database level:

.alter database [database_name] policy merge '{}'