Effect of Request Cache Peeking on EXPLAIN Reports - Teradata Database

SQL Data Manipulation Language

Product
Teradata Database
Release Number
15.10
Language
English (United States)
Last Update
2018-10-06
dita:id
B035-1146
lifecycle
previous
Product Category
Teradata® Database

Effect of Request Cache Peeking on EXPLAIN Reports

If you specify USING data, or if you specify a DATE or CURRENT_DATE built‑in function in a request, or both, the system can invoke Request Cache peeking. See SQL Request and Transaction Processing. In this case, the EXPLAIN text indicates the peeked literal values.

If you do not specify USING data, or if the USING variables, DATE or CURRENT_DATE values, or both are not peeked, then there is no impact on either the generated plan or the generated EXPLAIN text.

Note that parameterized requests specified without a USING request modifier, but using either CLIv2 data parcel flavor 3 (Data) or CLIv2 parcel flavor 71 (DataInfo), cannot be explained using any of the following request modifiers or statements:

  • EXPLAIN
  • DUMP EXPLAIN
  • INSERT EXPLAIN
  • For details about data parcel formats, see Teradata Call-Level Interface Version 2 Reference for Mainframe-Attached Systems or Teradata Call-Level Interface Version 2 Reference for Workstation-Attached Systems.