CLUSTER BY

In the Ultra Transcenders books

DBX-DEP

Each book explains CLUSTER BY 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.

• Set

  Secret permission in Key Vault for writing secrets; some older material refers to it as Create.

• 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.

• KEYS

  Lists the column or columns that identify each target row uniquely in an AUTO CDC statement.

• Databricks

  Analytics platform built on Apache Spark where data is processed in notebooks; Unity Catalog is the governance model it recommends.

• SELECT

  A DML command in SQL used to retrieve rows from one table or several.

Related terms

• --attach-acr

  Option on az aks create or az aks update that links a container registry to an AKS cluster by assigning AcrPull to the kubelet identity, so nodes can pull its images.

• Automatic liquid clustering

  Enabled by CLUSTER BY AUTO for managed tables in Unity Catalog. It relies on predictive optimization to study how a table is queried, select clustering keys and swap them once the expected benefit is greater than the expense.

• Data clustering

  A Fabric Data Warehouse preview capability that, as data is loaded, keeps rows with similar values in up to four chosen columns physically together, letting filtered queries avoid reading irrelevant files. You set it once with WITH (CLUSTER BY (...)) in CREATE TABLE or CTAS and cannot alter it afterwards; lakehouse Delta liquid clustering is a different feature.

• vSAN datastore sharing

  Lets one vSAN cluster use storage from another, whether a vSAN HCI or storage cluster, by mounting its datastore, even under a different vCenter; it was previously called HCI Mesh.