Supported data sources and file types
This article discusses currently supported data sources, file types, and scanning concepts in the Microsoft Purview Data Map.
Microsoft Purview Data Map available data sources
The table below shows the supported capabilities for each data source. Select the data source, or the feature, to learn more.
Currently, the Microsoft Purview Data Map can't scan an asset that has
# in its name. To scope your scan and avoid scanning assets that have those characters in the asset name, use the example in Register and scan an Azure SQL Database.
If you plan on using a self-hosted integration runtime, scanning some data sources requires additional setup on the self-hosted integration runtime machine. For example, JDK, Visual C++ Redistributable, or specific driver. For your source, refer to each source article for prerequisite details. Any requirements will be listed in the Prerequisites section.
The following is a list of all the Azure data source (data center) regions where the Microsoft Purview Data Map scanner runs. If your Azure data source is in a region outside of this list, the scanner will run in the region of your Microsoft Purview instance.
Microsoft Purview Data Map scanner regions
- Australia East
- Australia Southeast
- Brazil South
- Canada Central
- Central India
- Central US
- East Asia
- East US
- East US 2
- France Central
- Japan East
- Korea Central
- North Central US
- North Europe
- South Africa North
- South Central US
- Southeast Asia
- UAE North
- UK South
- West Central US
- West Europe
- West US
- West US 2
- West US 3
File types supported for scanning
The following file types are supported for scanning, for schema extraction, and classification where applicable:
- Structured file formats supported by extension: AVRO, ORC, PARQUET, CSV, JSON, PSV, SSV, TSV, TXT, XML, GZIP
- The Microsoft Purview Data Map scanner only supports schema extraction for the structured file types listed above.
- For AVRO, ORC, and PARQUET file types, the scanner does not support schema extraction for files that contain complex data types (for example, MAP, LIST, STRUCT).
- The scanner supports scanning snappy compressed PARQUET types for schema extraction and classification.
- For GZIP file types, the GZIP must be mapped to a single csv file within. Gzip files are subject to System and Custom Classification rules. We currently don't support scanning a gzip file mapped to multiple files within, or any file type other than csv.
- For delimited file types (CSV, PSV, SSV, TSV, TXT), we do not support data type detection. The data type will be listed as "string" for all columns. We only support comma(‘,’), semicolon(‘;’), vertical bar(‘|’) and tab(‘\t’) as delimiter. If the field doesn't have quotes on the ends, or the field is a single quote char or there are quotes within the field, the row will be judged as error row. Rows that have different number of columns than the header row will be judged as error rows. (numbers of error rows / numbers of rows sampled ) must be less than 0.1.
- For Parquet files, if you are using a self-hosted integration runtime, you need to install the 64-bit JRE 8 (Java Runtime Environment) or OpenJDK on your IR machine. Check our Java Runtime Environment section at the bottom of the page for an installation guide.
- Document file formats supported by extension: DOC, DOCM, DOCX, DOT, ODP, ODS, ODT, PDF, POT, PPS, PPSX, PPT, PPTM, PPTX, XLC, XLS, XLSB, XLSM, XLSX, XLT
- The Microsoft Purview Data Map also supports custom file extensions and custom parsers.
Currently, the maximum number of columns supported in asset schema tab is 800 for Azure sources, Power BI and SQL server.
Currently, nested data is only supported for JSON content.
For all system supported file types, if there's nested JSON content in a column, then the scanner parses the nested JSON data and surfaces it within the schema tab of the asset.
Nested data, or nested schema parsing, isn't supported in SQL. A column with nested data will be reported and classified as is, and subdata won't be parsed.
Sampling data for classification
In Microsoft Purview Data Map terminology,
- L1 scan: Extracts basic information and meta data like file name, size and fully qualified name
- L2 scan: Extracts schema for structured file types and database tables
- L3 scan: Extracts schema where applicable and subjects the sampled file to system and custom classification rules
For all structured file formats, the Microsoft Purview Data Map scanner samples files in the following way:
- For structured file types, it samples the top 128 rows in each column or the first 1 MB, whichever is lower.
- For document file formats, it samples the first 20 MB of each file.
- If a document file is larger than 20 MB, then it isn't subject to a deep scan (subject to classification). In that case, Microsoft Purview captures only basic meta data like file name and fully qualified name.
- For tabular data sources (SQL), it samples the top 128 rows.
- For Azure Cosmos DB for NoSQL, up to 300 distinct properties from the first 10 documents in a container will be collected for the schema and for each property, values from up to 128 documents or the first 1 MB will be sampled.
Resource set file sampling
A folder or group of partition files is detected as a resource set in the Microsoft Purview Data Map if it matches with a system resource set policy or a customer defined resource set policy. If a resource set is detected, then the scanner will sample each folder that it contains. Learn more about resource sets here.
File sampling for resource sets by file types:
- Delimited files (CSV, PSV, SSV, TSV) - 1 in 100 files are sampled (L3 scan) within a folder or group of partition files that are considered a 'Resource set'
- Data Lake file types (Parquet, Avro, Orc) - 1 in 18446744073709551615 (long max) files are sampled (L3 scan) within a folder or group of partition files that are considered a 'Resource set'
- Other structured file types (JSON, XML, TXT) - 1 in 100 files are sampled (L3 scan) within a folder or group of partition files that are considered a 'Resource set'
- SQL objects and Azure Cosmos DB entities - Each file is L3 scanned.
- Document file types - Each file is L3 scanned. Resource set patterns don't apply to these file types.