XML for Analysis¶

Expose analytical data and metadata through a vendor-neutral SOAP protocol centered on two operations—Discover for schema rowsets and Execute for multidimensional or tabular query results.

Version: v1 · 2026-08-30 · History
Domain-specific #: 3129
Origin domain: analytical data systems
Subdomain: olap interoperability
Aliases: XMLA, XML/A, XML for Analysis protocol

Core Idea¶

XML for Analysis (XMLA) is a SOAP-based interoperability protocol for accessing analytical systems, especially online analytical processing (OLAP) servers. It reduces the client/server contract to two principal methods. Discover retrieves metadata—data sources, catalogs, cubes, dimensions, measures, members, properties, and supported schema rowsets. Execute submits an analytical command and returns either a multidimensional dataset or a tabular rowset. XML envelopes, schemas, namespaces, properties, restrictions, and transport conventions make the requests vendor-neutral and remotely callable.

The protocol was proposed as a web-service successor to tightly coupled analytical APIs such as OLE DB for OLAP and standardized through the XMLA Council with Microsoft, Hyperion, SAS, and other vendors.

Scope of Application¶

XMLA is used by multidimensional database servers, semantic-model platforms, OLAP clients, reporting tools, spreadsheet connections, administration utilities, and cross-vendor BI middleware. It supports discovery-driven clients that learn a provider's catalogs and cube schema before composing commands.

The node covers the protocol family and conforming implementations, including metadata rowsets and command execution. Product-specific extensions must be labeled. Modern Analysis Services documentation continues to specify Discover and Execute elements, but not every server supporting “XMLA endpoints” implements every historical feature identically.

Clarity¶

Recognize XMLA by its wire contract. A Discover request in the urn:schemas-microsoft-com:xml-analysis namespace carries RequestType, Restrictions, and Properties; it returns an XMLA rowset. An Execute request carries Command and Properties; its response contains a rowset or multidimensional dataset. If an XML document merely exports a cube or embeds an MDX string without these operations, it is not necessarily XMLA.

Manages Complexity¶

Analytical systems expose many object types and operations. A method-per-object remote API would grow with every cube feature. XMLA keeps the service surface small. RequestType selects metadata families within Discover, while command payloads carry the analytical language through Execute. Properties supply a uniform context channel.

This separation enables generic clients. They can introspect a provider instead of compiling vendor-specific schemas into every release.

Abstract Reasoning¶

Discovery enables late binding. A client can adapt to catalogs and capabilities found at runtime. 2. Two operations minimize interface proliferation. New metadata families and commands can evolve without a new remote method for each object. 3. Interoperability requires semantic conformance. Parsing the XML is insufficient if providers interpret properties or cellsets differently. 4. Payload language remains orthogonal. XMLA can transport several command dialects while preserving its service contract.

Knowledge Transfer¶

Within BI systems, XMLA transfers across vendor clients and servers when both honor the same request types, schemas, and query dialects. A client can reuse discovery, execution, and result parsing against multiple providers while isolating extensions.

Architecturally, its two-operation pattern transfers to reflective APIs: first enumerate capabilities and metadata, then submit operations against discovered identifiers. The broader abstraction is interoperability through introspection, not XMLA itself.

Relationships to Other Abstractions¶

Current abstraction XML for Analysis Domain-specific

Parents (1) — more general patterns this builds on

XML for Analysis is part of Interoperability Prime

optional state links multiple calls.

Hierarchy paths (2) — routes to 2 parentless roots

XML for Analysis → Interoperability → Compatibility

Show alternative path (1)

Neighborhood in Abstraction Space¶

XML for Analysis sits in a sparse region of the domain-specific corpus (99^th percentile for distinctiveness): few abstractions share its structure, so a faithful description tends to retrieve it precisely.

Family — Messaging Protocols & Networked Services (23 abstractions)

Nearest neighbors

Computed from structural-signature embeddings · 2026-09-08