SQL provides a powerful facility for analyzing the request plans the Optimizer creates for various data manipulation statements. This feature, called the Query Capture Facility, permits a DBA to capture access plan information from the Optimizer using the SQL statements COLLECT DEMOGRAPHICS, DUMP EXPLAIN, INSERT EXPLAIN, and BEGIN QUERY CAPTURE (see Teradata Vantage™ - SQL Data Definition Language Syntax and Examples, B035-1144 for more information about these statements) and then analyze the captured data using standard SQL DML statements.
The captured request plans are stored in a relational database called a Query Capture Database (QCD) that you can create for that purpose. QCD is a user database whose space is drawn from available permanent disk space: it is not a set of system tables found in a fixed location.
- Store all request plans for customer requests. You can then compare and contrast requests as a function of software release, hardware platform, and hardware configuration.
- Provide data so that you can generate your own detailed analyses of captured request steps using standard SQL DML statements and third-party request management tools.