Partitioning

In the Ultra Transcenders books

DP-750DP-700

Each book explains Partitioning in context, with comparison tables and the common traps.

Terms in this definition

• Event

  Table in Log Analytics where entries from Windows event logs are kept.

• Liquid clustering

  Organises a table's data around up to four clustering keys set with CLUSTER BY, as an alternative to both partitioning and ZORDER. The keys can be changed without rewriting existing files, and CLUSTER BY AUTO hands key selection to predictive optimization.

Related terms

• Container

  Something that groups data. Blob Storage containers sit inside a storage account and hold blobs much as folders hold files; Cosmos DB containers hold items and set the scope for partitioning and throughput.

• Degree of copy parallelism

  The upper limit on simultaneous read or write threads in a Copy activity, configured separately from intelligent throughput optimisation. With partitioning in use it governs how many partition queries run together, so a value that is too large risks overwhelming the source system.

• Ingestion time clustering

  Delta lays out data in unpartitioned tables in the order it arrives, which speeds up date-based filtering much as partitioning would, with nothing to configure.

• MBR

  An older partitioning scheme tied to BIOS, allowing at most four primary partitions and disks up to 2 TB. On UEFI machines, GPT takes its place.

• PERSISTED

  A computed-column setting that saves the calculated result and refreshes it whenever the source values change, rather than working it out at read time; certain indexing and partitioning scenarios depend on it.

• Stream group

  Made with sys.sp_create_event_stream_group, this change event streaming object says where changes go (Fabric Eventstream or Azure Event Hubs) and which tables are included, along with the credential, message size and partitioning.