Add script for generating DuckDB answer files

inst/tpch/duckdb_answers_script.R

@@ -0,0 +1,46 @@
+library(substrait)
+library(dplyr)
+library(duckdb)
+library(arrowbench)
+
+
+sf <- 0.1
+tpch_files <- ensure_source("tpch", scale_factor = sf)
+
+con <- dbConnect(duckdb::duckdb("temp"))
+dbExecute(con, paste0("PRAGMA threads=10"))
+
+# DuckDB tables
+for (name in tpch_tables) {
+  file <- path.expand(tpch_files[[name]])
+
+  sql_query <- paste0("CREATE TABLE ", name, " AS SELECT * FROM parquet_scan('", file, "');")
+
+  file <- tpch_files[[name]]
+  dbExecute(con, sql_query)
+}
+
+input_functions[["duckdb"]] <- function(name) {
+  return(dplyr::tbl(con, name))
+}
+
+for (q in c(1:22)) {
+  message("==================================================")
+  message(glue::glue("Query: {q}"))
+  message("==================================================")
+
+  tryCatch({
+
+    query <- q
+
+    # grab the sql queries from github (this URL might need to be updated if their location in the repo changes.)
+    sql <- paste0(httr::GET(
+      glue::glue("https://raw.githubusercontent.com/duckdb/duckdb/master/extension/tpch/dbgen/queries/q{stringr::str_pad(query, 2, pad = '0')}.sql")
+    ), collapse = "\n")
+
+    result_duckdb <- as_tibble(dbGetQuery(con, sql))
+
+    arrow::write_parquet(result_duckdb, file.path("answers", "scale-factor-0.1", paste0("tpch-q", q, ".parquet")))
+
+ }, error = function(e) print(paste("Error in query", q, ":", conditionMessage(e))))
+}