Azure Data Explorer data ingestion properties

Data ingestion is the process by which data is added to a table and is made available for query in Azure Data Explorer. You add properties to the ingestion command after the with keyword.

Ingestion properties


  • In queued ingestion data is batched using Ingestion properties. The more distinct ingestion mapping properties used, such as different ConstValue values, the more fragmented the ingestion becomes, which can lead to performance degradation.

The following table lists the properties supported by Azure Data Explorer, describes them, and provides examples:

Property Description Example
ingestionMapping A string value that indicates how to map data from the source file to the actual columns in the table. Define the format value with the relevant mapping type. See data mappings. with (format="json", ingestionMapping = "[{\"column\":\"rownumber\", \"Properties\":{\"Path\":\"$.RowNumber\"}}, {\"column\":\"rowguid\", \"Properties\":{\"Path\":\"$.RowGuid\"}}]")
(deprecated: avroMapping, csvMapping, jsonMapping)
ingestionMappingReference A string value that indicates how to map data from the source file to the actual columns in the table using a named mapping policy object. Define the format value with the relevant mapping type. See data mappings. with (format="csv", ingestionMappingReference = "Mapping1")
(deprecated: avroMappingReference, csvMappingReference, jsonMappingReference)
creationTime The datetime value (formatted as an ISO8601 string) to use at the creation time of the ingested data extents. If unspecified, the current value (now()) will be used. Overriding the default is useful when ingesting older data, so that the retention policy will be applied correctly. When specified, make sure the Lookback property in the target table's effective Extents merge policy is aligned with the specified value. with (creationTime="2017-02-13")
extend_schema A Boolean value that, if specified, instructs the command to extend the schema of the table (defaults to false). This option applies only to .append and .set-or-append commands. The only allowed schema extensions have additional columns added to the table at the end. If the original table schema is (a:string, b:int), a valid schema extension would be (a:string, b:int, c:datetime, d:string), but (a:string, c:datetime) wouldn't be valid
folder For ingest-from-query commands, the folder to assign to the table. If the table already exists, this property will override the table's folder. with (folder="Tables/Temporary")
format The data format (see supported data formats). with (format="csv")
ingestIfNotExists A string value that, if specified, prevents ingestion from succeeding if the table already has data tagged with an ingest-by: tag with the same value. This ensures idempotent data ingestion. For more information, see ingest-by: tags. The properties with (ingestIfNotExists='["Part0001"]', tags='["ingest-by:Part0001"]') indicate that if data with the tag ingest-by:Part0001 already exists, then don't complete the current ingestion. If it doesn't already exist, this new ingestion should have this tag set (in case a future ingestion attempts to ingest the same data again.)
ignoreFirstRecord A Boolean value that, if set to true, indicates that ingestion should ignore the first record of every file. This property is useful for files in CSVand similar formats, if the first record in the file are the column names. By default, false is assumed. with (ignoreFirstRecord=false)
policy_ingestiontime A Boolean value that, if specified, describes whether to enable the Ingestion Time Policy on a table that is created by this command. The default is true. with (policy_ingestiontime=false)
recreate_schema A Boolean value that, if specified, describes whether the command may recreate the schema of the table. This property applies only to the .set-or-replace command. This property takes precedence over the extend_schema property if both are set. with (recreate_schema=true)
tags A list of tags to associate with the ingested data, formatted as a JSON string with (tags="['Tag1', 'Tag2']")
validationPolicy A JSON string that indicates which validations to run during ingestion of data represented using CSV format. See Data ingestion for an explanation of the different options. with (validationPolicy='{"ValidationOptions":1, "ValidationImplications":1}') (this is actually the default policy)
zipPattern Use this property when ingesting data from storage that has a ZIP archive. This is a string value indicating the regular expression to use when selecting which files in the ZIP archive to ingest. All other files in the archive will be ignored. with (zipPattern="*.csv")