cloud-fan commented on a change in pull request #24068: [SPARK-27105][SQL]
Optimize away exponential complexity in ORC predicate conversion
URL: https://github.com/apache/spark/pull/24068#discussion_r293209902
##########
File path:
sql/core/src/test/scala/org/apache/spark/sql/execution/benchmark/FilterPushdownBenchmark.scala
##########
@@ -362,6 +394,13 @@ object FilterPushdownBenchmark extends BenchmarkBase with
SQLHelper {
}
runBenchmark(s"Pushdown benchmark with many filters") {
+ // This benchmark and the next one are similar in that they both test
predicate pushdown
+ // where the filter itself is very large. There have been cases where
the filter conversion
+ // would take minutes to hours for large filters due to it being
implemented with exponential
+ // complexity in the height of the filter tree.
+ // The difference between these two benchmarks is that this one
benchmarks pushdown with a
+ // large string filter (`a AND b AND c ...`), whereas the next one
benchmarks pushdown with
+ // a large Column-based filter (`col(a) || (col(b) || (col(c)...))`).
Review comment:
I still can't get it. Both the string filter and column-based filter will
become an `Expression` in the `Filter` operator. The differences I see are
1. the new benchmark builds a larger filter
2. the new benchmark use `Or` instead of `And`.
----------------------------------------------------------------
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
For queries about this service, please contact Infrastructure at:
us...@infra.apache.org
With regards,
Apache Git Services
---------------------------------------------------------------------
To unsubscribe, e-mail: reviews-unsubscr...@spark.apache.org
For additional commands, e-mail: reviews-h...@spark.apache.org
