dongjoon-hyun commented on code in PR #48661:
URL: https://github.com/apache/spark/pull/48661#discussion_r1817912578
##########
sql/catalyst/src/main/scala/org/apache/spark/sql/internal/SQLConf.scala:
##########
@@ -5207,6 +5207,16 @@ object SQLConf {
.booleanConf
.createWithDefault(false)
+ val ORDERING_AWARE_LIMIT_OFFSET =
buildConf("spark.sql.orderingAwareLimitOffset")
+ .internal()
+ .doc("When set to true, a local sort will be inserted between
GlobalLimitExec and " +
+ "single-partition ShuffleExchangeExec, if the underlying plan produces
sorted data. " +
+ "This is because shuffle reader in Spark fetches shuffle blocks in a
random order and " +
+ "can not preserve the data ordering, while LIMIT/OFFSET must preserve
ordering.")
+ .version("4.0.0")
+ .booleanConf
+ .createWithDefault(true)
Review Comment:
Since this is `true` by default, we need a migration guide, don't we,
@cloud-fan ?
--
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.
To unsubscribe, e-mail: [email protected]
For queries about this service, please contact Infrastructure at:
[email protected]
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
