tests/testthat/_snaps/explain.md

In duckdb: DBI Package for the DuckDB Database Management System

EXPLAIN gives reasonable output

Code
  DBI::dbGetQuery(con, "EXPLAIN SELECT 1;")
Output
  physical_plan
  ┌───────────────────────────┐
  │         PROJECTION        │
  │   ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─   │
  │             1             │
  └─────────────┬─────────────┘                             
  ┌─────────────┴─────────────┐
  │         DUMMY_SCAN        │
  └───────────────────────────┘

EXPLAIN shows logical, optimized and physical plan

Code
  DBI::dbExecute(con, "PRAGMA explain_output='all';")
Output
  [1] 0
Code
  DBI::dbGetQuery(con, "EXPLAIN SELECT 1;")
Output
  logical_plan
  ┌───────────────────────────┐
  │         PROJECTION        │
  │   ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─   │
  │             1             │
  └─────────────┬─────────────┘                             
  ┌─────────────┴─────────────┐
  │         DUMMY_SCAN        │
  └───────────────────────────┘                             
  logical_opt
  ┌───────────────────────────┐
  │         PROJECTION        │
  │   ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─   │
  │             1             │
  └─────────────┬─────────────┘                             
  ┌─────────────┴─────────────┐
  │         DUMMY_SCAN        │
  └───────────────────────────┘                             
  physical_plan
  ┌───────────────────────────┐
  │         PROJECTION        │
  │   ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─   │
  │             1             │
  └─────────────┬─────────────┘                             
  ┌─────────────┴─────────────┐
  │         DUMMY_SCAN        │
  └───────────────────────────┘

zero length input is smoothly skipped

Code
  rs <- DBI::dbGetQuery(con, "SELECT 1;")
  rs[FALSE, ]
Output
  integer(0)

wrong type of input forwards handling to the next method

Code
  rs <- DBI::dbGetQuery(con, "SELECT 1;")
  class(rs) <- c("duckdb_explain", class(rs))
  rs
Output
    1
  1 1

duckdb documentation built on Nov. 17, 2023, 5:08 p.m.