Resolver | SQL Request and Transaction Processing | Teradata Vantage - 17.10 - Resolver - Advanced SQL Engine - Teradata Database

Teradata Vantageā„¢ - SQL Request and Transaction Processing

Product
Advanced SQL Engine
Teradata Database
Release Number
17.10
Release Date
July 2021
Content Type
Programming Reference
User Guide
Publication ID
B035-1142-171K
Language
English (United States)

The Resolver annotates the SynTree with information about such things as data conversions, column names, discretionary access control security checks, and underlying relationships, and then produces a more fleshed out parse tree called a ResTree or Red Tree.

The following provides an overview of the activities performed by the Resolver:
  1. The Resolver takes the SynTree as its input from the Syntaxer.
  2. Each database or user, table, view, trigger, stored procedure, and macro is assigned a globally unique numeric ID.

    Each column and each index is assigned a numeric ID that is unique within its table.

    These IDs are maintained in the Data Dictionary.

  3. The Resolver refers to the Data Dictionary to verify all names and privileges and to convert those names to their equivalent numeric IDs.
  4. The Resolver takes available information from the Data Dictionary cache, which is used on a least-recently-used or most-recently-used basis.

    If the needed information is not cached, it is retrieved from the appropriate system tables.

  5. If a request parcel contains views or macros, the Resolver retrieves the view or macro text from the Data Dictionary, resolves it, and then merges the elements of the resulting tree into the request tree.
  6. The Resolver produces the ResTree as its output and passes it on to Security.