Daily DAX : Day 92 INFO.SEGMENTSTORAGES

 INFO.SEGMENTSTORAGES is one of the new DAX functions introduced in the context of Dynamic Management Views (DMVs) for Power BI models:

INFO.SEGMENTSTORAGES:

    Function Purpose: INFO.SEGMENTSTORAGES retrieves metadata about how data segments or partitions are stored within a Power BI semantic model. This function is part of the new set of INFO functions that are essentially DAX equivalents of the TMSCHEMA DMVs used in SQL Server Analysis Services (SSAS) or Azure Analysis Services. 

    Syntax: The syntax would typically be:

    DAX

    EVALUATE

    INFO.SEGMENTSTORAGES()

    Return Values: This function would return a table with columns detailing:

        Segment ID

        Storage Type (e.g., In-Memory, DirectQuery, Hybrid)

        Size of the segment

        Compression status or method

        Possibly memory usage or other storage specifics

Main Use Case:

    Performance Monitoring and Optimization: 

        Query Performance: Understanding how data is segmented and stored allows BI professionals to diagnose performance bottlenecks. For instance, if certain segments are too large or not optimized for querying, this can lead to slow report rendering or data refresh times.

        Storage Management: By knowing which segments are stored how, developers can make informed decisions about moving data between storage modes (like from Import to DirectQuery for very large datasets) to optimize for both speed and memory usage.

        Resource Planning: This function helps in understanding memory consumption patterns, which is critical for capacity planning, especially for Power BI deployments on Azure or on-premises environments where resources need to be managed efficiently.

    Model Documentation and Governance:

        Documentation: It aids in documenting the model's structure, which is vital for maintenance, especially in complex models where understanding segment storage can help in managing updates or troubleshooting.

        Compliance and Governance: For organizations where data governance is key, knowing how data is physically stored can assist in ensuring compliance with data residency or security policies.

    Debugging:

        Issue Resolution: When facing unexpected behavior or errors in data processing, this function could help pinpoint issues related to data storage, like unexpected segment growth or improper partitioning.

Since these functions are relatively new (introduced in the December 2023 Power BI Desktop release), they are aimed at providing deeper insights into the model's performance and structure, enhancing capabilities for model management, performance tuning, and strategic decision-making in data handling within Power BI.

https://dax.guide/info-segmentstorages/