In https://github.com/apache/spark/pull/9409 we enabled multi-column counting. The approach taken in that PR introduces a bit of overhead by first creating a row only to check if all of the columns are non-null.
This PR fixes that technical debt. Count now takes multiple columns as its input. In order to make this work I have also added support for multiple columns in the single distinct code path.
cc yhuai
Author: Herman van Hovell <hvanhovell@questtec.nl>
Closes#10015 from hvanhovell/SPARK-12024.
Check for partition column null-ability while building the partition spec.
Author: Dilip Biswal <dbiswal@us.ibm.com>
Closes#10001 from dilipbiswal/spark-11997.
Reference: https://jdbc.postgresql.org/documentation/head/query.html#query-with-cursor
In order for PostgreSQL to honor the fetchSize non-zero setting, its Connection.autoCommit needs to be set to false. Otherwise, it will just quietly ignore the fetchSize setting.
This adds a new side-effecting dialect specific beforeFetch method that will fire before a select query is ran.
Author: mariusvniekerk <marius.v.niekerk@gmail.com>
Closes#9861 from mariusvniekerk/SPARK-11881.
On the live web UI, there is a SQL tab which provides valuable information for the SQL query. But once the workload is finished, we won't see the SQL tab on the history server. It will be helpful if we support SQL UI on the history server so we can analyze it even after its execution.
To support SQL UI on the history server:
1. I added an `onOtherEvent` method to the `SparkListener` trait and post all SQL related events to the same event bus.
2. Two SQL events `SparkListenerSQLExecutionStart` and `SparkListenerSQLExecutionEnd` are defined in the sql module.
3. The new SQL events are written to event log using Jackson.
4. A new trait `SparkHistoryListenerFactory` is added to allow the history server to feed events to the SQL history listener. The SQL implementation is loaded at runtime using `java.util.ServiceLoader`.
Author: Carson Wang <carson.wang@intel.com>
Closes#9297 from carsonwang/SqlHistoryUI.
Currently, we does not have visualization for SQL query from Python, this PR fix that.
cc zsxwing
Author: Davies Liu <davies@databricks.com>
Closes#9949 from davies/pyspark_sql_ui.
Except inner join, maybe the other join types are also useful when users are using the joinWith function. Thus, added the joinType into the existing joinWith call in Dataset APIs.
Also providing another joinWith interface for the cartesian-join-like functionality.
Please provide your opinions. marmbrus rxin cloud-fan Thank you!
Author: gatorsmile <gatorsmile@gmail.com>
Closes#9921 from gatorsmile/joinWith.
This patch makes it consistent to use varargs in all DataFrameReader methods, including Parquet, JSON, text, and the generic load function.
Also added a few more API tests for the Java API.
Author: Reynold Xin <rxin@databricks.com>
Closes#9945 from rxin/SPARK-11967.
This PR is to provide two common `coalesce` and `repartition` in Dataset APIs.
After reading the comments of SPARK-9999, I am unclear about the plan for supporting re-partitioning in Dataset APIs. Currently, both RDD APIs and Dataframe APIs provide users such a flexibility to control the number of partitions.
In most traditional RDBMS, they expose the number of partitions, the partitioning columns, the table partitioning methods to DBAs for performance tuning and storage planning. Normally, these parameters could largely affect the query performance. Since the actual performance depends on the workload types, I think it is almost impossible to automate the discovery of the best partitioning strategy for all the scenarios.
I am wondering if Dataset APIs are planning to hide these APIs from users? Feel free to reject my PR if it does not match the plan.
Thank you for your answers. marmbrus rxin cloud-fan
Author: gatorsmile <gatorsmile@gmail.com>
Closes#9899 from gatorsmile/coalesce.
Currently pivot's signature looks like
```scala
scala.annotation.varargs
def pivot(pivotColumn: Column, values: Column*): GroupedData
scala.annotation.varargs
def pivot(pivotColumn: String, values: Any*): GroupedData
```
I think we can remove the one that takes "Column" types, since callers should always be passing in literals. It'd also be more clear if the values are not varargs, but rather Seq or java.util.List.
I also made similar changes for Python.
Author: Reynold Xin <rxin@databricks.com>
Closes#9929 from rxin/SPARK-11946.
we should pass in resolved encodera to logical `CoGroup` and bind them in physical `CoGroup`
Author: Wenchen Fan <wenchen@databricks.com>
Closes#9928 from cloud-fan/cogroup.
Based on feedback from Matei, this is more consistent with mapPartitions in Spark.
Also addresses some of the cleanups from a previous commit that renames the type variables.
Author: Reynold Xin <rxin@databricks.com>
Closes#9919 from rxin/SPARK-11933.
1. Renamed map to mapGroup, flatMap to flatMapGroup.
2. Renamed asKey -> keyAs.
3. Added more documentation.
4. Changed type parameter T to V on GroupedDataset.
5. Added since versions for all functions.
Author: Reynold Xin <rxin@databricks.com>
Closes#9880 from rxin/SPARK-11899.
In this PR I delete a method that breaks type inference for aggregators (only in the REPL)
The error when this method is present is:
```
<console>:38: error: missing parameter type for expanded function ((x$2) => x$2._2)
ds.groupBy(_._1).agg(sum(_._2), sum(_._3)).collect()
```
Author: Michael Armbrust <michael@databricks.com>
Closes#9870 from marmbrus/dataset-repl-agg.
This mainly moves SqlNewHadoopRDD to the sql package. There is some state that is
shared between core and I've left that in core. This allows some other associated
minor cleanup.
Author: Nong Li <nong@databricks.com>
Closes#9845 from nongli/spark-11787.
DataSet APIs look great! However, I am lost when doing multiple level joins. For example,
```
val ds1 = Seq(("a", 1), ("b", 2)).toDS().as("a")
val ds2 = Seq(("a", 1), ("b", 2)).toDS().as("b")
val ds3 = Seq(("a", 1), ("b", 2)).toDS().as("c")
ds1.joinWith(ds2, $"a._2" === $"b._2").as("ab").joinWith(ds3, $"ab._1._2" === $"c._2").printSchema()
```
The printed schema is like
```
root
|-- _1: struct (nullable = true)
| |-- _1: struct (nullable = true)
| | |-- _1: string (nullable = true)
| | |-- _2: integer (nullable = true)
| |-- _2: struct (nullable = true)
| | |-- _1: string (nullable = true)
| | |-- _2: integer (nullable = true)
|-- _2: struct (nullable = true)
| |-- _1: string (nullable = true)
| |-- _2: integer (nullable = true)
```
Personally, I think we need the printSchema function. Sometimes, I do not know how to specify the column, especially when their data types are mixed. For example, if I want to write the following select for the above multi-level join, I have to know the schema:
```
newDS.select(expr("_1._2._2 + 1").as[Int]).collect()
```
marmbrus rxin cloud-fan Do you have the same feeling?
Author: gatorsmile <gatorsmile@gmail.com>
Closes#9855 from gatorsmile/printSchemaDataSet.
Apply the user supplied pathfilter while retrieving the files from fs.
Author: Dilip Biswal <dbiswal@us.ibm.com>
Closes#9830 from dilipbiswal/spark-11544.
In addition, tightened visibility of a lot of classes in the columnar package from private[sql] to private[columnar].
Author: Reynold Xin <rxin@databricks.com>
Closes#9842 from rxin/SPARK-11858.
Fix a bug in DataFrameReader.table (table with schema name such as "db_name.table" doesn't work)
Use SqlParser.parseTableIdentifier to parse the table name before lookupRelation.
Author: Huaxin Gao <huaxing@oc0558782468.ibm.com>
Closes#9773 from huaxingao/spark-11778.
After some experiment, I found it's not convenient to have separate encoder builders: `FlatEncoder` and `ProductEncoder`. For example, when create encoders for `ScalaUDF`, we have no idea if the type `T` is flat or not. So I revert the splitting change in https://github.com/apache/spark/pull/9693, while still keeping the bug fixes and tests.
Author: Wenchen Fan <wenchen@databricks.com>
Closes#9726 from cloud-fan/follow.
When debugging DataSet API, I always need to print the logical and physical plans.
I am wondering if we should provide a simple API for EXPLAIN?
Author: gatorsmile <gatorsmile@gmail.com>
Closes#9832 from gatorsmile/explainDS.
When handling self joins, the implementation did not consider the case insensitivity of HiveContext. It could cause an exception as shown in the JIRA:
```
TreeNodeException: Failed to copy node.
```
The fix is low risk. It avoids unnecessary attribute replacement. It should not affect the existing behavior of self joins. Also added the test case to cover this case.
Author: gatorsmile <gatorsmile@gmail.com>
Closes#9762 from gatorsmile/joinMakeCopy.
This patch adds an alternate to the Parquet RecordReader from the parquet-mr project
that is much faster for flat schemas. Instead of using the general converter mechanism
from parquet-mr, this directly uses the lower level APIs from parquet-columnar and a
customer RecordReader that directly assembles into UnsafeRows.
This is optionally disabled and only used for supported schemas.
Using the tpcds store sales table and doing a sum of increasingly more columns, the results
are:
For 1 Column:
Before: 11.3M rows/second
After: 18.2M rows/second
For 2 Columns:
Before: 7.2M rows/second
After: 11.2M rows/second
For 5 Columns:
Before: 2.9M rows/second
After: 4.5M rows/second
Author: Nong Li <nong@databricks.com>
Closes#9774 from nongli/parquet.
Before this PR there were two things that would blow up if you called `df.as[MyClass]` if `MyClass` was defined in the REPL:
- [x] Because `classForName` doesn't work on the munged names returned by `tpe.erasure.typeSymbol.asClass.fullName`
- [x] Because we don't have anything to pass into the constructor for the `$outer` pointer.
Note that this PR is just adding the infrastructure for working with inner classes in encoder and is not yet sufficient to make them work in the REPL. Currently, the implementation show in 95cec7d413 is causing a bug that breaks code gen due to some interaction between janino and the `ExecutorClassLoader`. This will be addressed in a follow-up PR.
Author: Michael Armbrust <michael@databricks.com>
Closes#9602 from marmbrus/dataset-replClasses.
Apply the user supplied pathfilter while retrieving the files from fs.
Author: Dilip Biswal <dbiswal@us.ibm.com>
Closes#9652 from dilipbiswal/spark-11544.
Currently, if the first SQLContext is not removed after stopping SparkContext, a SQLContext could set there forever. This patch make this more robust.
Author: Davies Liu <davies@databricks.com>
Closes#9706 from davies/clear_context.
https://issues.apache.org/jira/browse/SPARK-11792
The main changes include:
* Renaming `SizeEstimation` to `KnownSizeEstimation`. Hopefully this new name has more information.
* Making `estimatedSize` return `Long` instead of `Option[Long]`.
* In `UnsaveHashedRelation`, `estimatedSize` will delegate the work to `SizeEstimator` if we have not created a `BytesToBytesMap`.
Since we will put `UnsaveHashedRelation` to `BlockManager`, it is generally good to let it provide a more accurate size estimation. Also, if we do not put `BytesToBytesMap` directly into `BlockerManager`, I feel it is not really necessary to make `BytesToBytesMap` extends `KnownSizeEstimation`.
Author: Yin Huai <yhuai@databricks.com>
Closes#9813 from yhuai/SPARK-11792-followup.
we use `ExpressionEncoder.tuple` to build the result encoder, which assumes the input encoder should point to a struct type field if it’s non-flat.
However, our keyEncoder always point to a flat field/fields: `groupingAttributes`, we should combine them into a single `NamedExpression`.
Author: Wenchen Fan <wenchen@databricks.com>
Closes#9792 from cloud-fan/agg.
When we resolve the join operator, we may change the output of right side if self-join is detected. So in `Dataset.joinWith`, we should resolve the join operator first, and then get the left output and right output from it, instead of using `left.output` and `right.output` directly.
Author: Wenchen Fan <wenchen@databricks.com>
Closes#9806 from cloud-fan/self-join.
I also found a bug with self-joins returning incorrect results in the Dataset API. Two test cases attached and filed SPARK-11803.
Author: Reynold Xin <rxin@databricks.com>
Closes#9789 from rxin/SPARK-11802.
I also wrote a test case -- but unfortunately the test case is not working due to SPARK-11795.
Author: Reynold Xin <rxin@databricks.com>
Closes#9784 from rxin/SPARK-11503.
Currently the size of cached batch in only controlled by `batchSize` (default value is 10000), which does not work well with the size of serialized columns (for example, complex types). The memory used to build the batch is not accounted, it's easy to OOM (especially after unified memory management).
This PR introduce a hard limit as 4M for total columns (up to 50 columns of uncompressed primitive columns).
This also change the way to grow buffer, double it each time, then trim it once finished.
cc liancheng
Author: Davies Liu <davies@databricks.com>
Closes#9760 from davies/cache_limit.
