[SPARK-23214][SQL] cached data should not carry extra hint info #20394
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cloud-fan
commented
Jan 25, 2018
| // However, we also want to keep the hint info after cache lookup. Here we skip the hint | ||
| // node, so that the returned caching plan won't replace the hint node and drop the hint info | ||
| // from the original plan. | ||
| case hint: ResolvedHint => hint |
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A small clean up for #20365
cloud-fan
commented
Jan 25, 2018
| @@ -62,7 +62,7 @@ case class InMemoryRelation( | |||
| @transient child: SparkPlan, | |||
| tableName: Option[String])( | |||
| @transient var _cachedColumnBuffers: RDD[CachedBatch] = null, | |||
| val batchStats: LongAccumulator = child.sqlContext.sparkContext.longAccumulator, | |||
| val sizeInBytesStats: LongAccumulator = child.sqlContext.sparkContext.longAccumulator, | |||
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unrelated but this name is more accurate.
cloud-fan
commented
Jan 25, 2018
| val df1 = spark.createDataFrame(Seq((1, "4"), (2, "2"))).toDF("key", "value") | ||
| val df2 = spark.createDataFrame(Seq((1, "1"), (2, "2"))).toDF("key", "value") | ||
| val df1 = Seq((1, "4"), (2, "2")).toDF("key", "value") | ||
| val df2 = Seq((1, "1"), (2, "2")).toDF("key", "value") |
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some code style fixing
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Test build #86637 has finished for PR 20394 at commit
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gatorsmile
reviewed
Jan 25, 2018
| @@ -62,7 +62,7 @@ case class InMemoryRelation( | |||
| @transient child: SparkPlan, | |||
| tableName: Option[String])( | |||
| @transient var _cachedColumnBuffers: RDD[CachedBatch] = null, | |||
| val batchStats: LongAccumulator = child.sqlContext.sparkContext.longAccumulator, | |||
| val sizeInBytesStats: LongAccumulator = child.sqlContext.sparkContext.longAccumulator, | |||
| statsOfPlanToCache: Statistics = null) | |||
|
LGTM |
| }.getOrElse(currentFragment) | ||
| lookupCachedData(currentFragment) | ||
| .map(_.cachedRepresentation.withOutput(currentFragment.output)) | ||
| .getOrElse(currentFragment) |
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Thank you for pinging me, @cloud-fan . I see.
hvanhovell
reviewed
Jan 25, 2018
| // returned by cache lookup should not have hint info. If we lookup the cache with a | ||
| // semantically same plan with a different hint info, `CacheManager.useCachedData` will take | ||
| // care of it and retain the hint info in the lookup input plan. | ||
| statsOfPlanToCache.copy(hints = HintInfo()) |
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I am not sure I agree with this. If we cache a plan with a hint, then it is reasonable to expect that the hint is still in the plan. We do the same with temporary views.
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This is a new behavior we introduced in 2.3. I will first keep the behavior unchanged and merge it to 2.3.
We can have more discussion in the next release.
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Test build #86643 has finished for PR 20394 at commit
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LGTM Thanks! Merged to master/2.3 |
asfgit
pushed a commit
that referenced
this pull request
Jan 27, 2018
## What changes were proposed in this pull request? This is a regression introduced by #19864 When we lookup cache, we should not carry the hint info, as this cache entry might be added by a plan having hint info, while the input plan for this lookup may not have hint info, or have different hint info. ## How was this patch tested? a new test. Author: Wenchen Fan <[email protected]> Closes #20394 from cloud-fan/cache. (cherry picked from commit 5b5447c) Signed-off-by: gatorsmile <[email protected]>
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What changes were proposed in this pull request?
This is a regression introduced by #19864
When we lookup cache, we should not carry the hint info, as this cache entry might be added by a plan having hint info, while the input plan for this lookup may not have hint info, or have different hint info.
How was this patch tested?
a new test.