## What changes were proposed in this pull request?
Add AL2 license to metadata of all .md files.
This seemed to be the tidiest way as it will get ignored by .md renderers and other tools. Attempts to write them as markdown comments revealed that there is no such standard thing.
## How was this patch tested?
Doc build
Closes#24243 from srowen/SPARK-26918.
Authored-by: Sean Owen <sean.owen@databricks.com>
Signed-off-by: Sean Owen <sean.owen@databricks.com>
## What changes were proposed in this pull request?
This makes the `CurrentDate` expression and `current_date` function independent from time zone settings. New result is number of days since epoch in `UTC` time zone. Previously, Spark shifted the current date (in `UTC` time zone) according the session time zone which violets definition of `DateType` - number of days since epoch (which is an absolute point in time, midnight of Jan 1 1970 in UTC time).
The changes makes `CurrentDate` consistent to `CurrentTimestamp` which is independent from time zone too.
## How was this patch tested?
The changes were tested by existing test suites like `DateExpressionsSuite`.
Closes#24185 from MaxGekk/current-date.
Lead-authored-by: Maxim Gekk <max.gekk@gmail.com>
Co-authored-by: Maxim Gekk <maxim.gekk@databricks.com>
Signed-off-by: Wenchen Fan <wenchen@databricks.com>
## What changes were proposed in this pull request?
In the PR, I propose to use the SQL config `spark.sql.session.timeZone` in formatting `TIMESTAMP` literals, and make formatting `DATE` literals independent from time zone. The changes make parsing and formatting `TIMESTAMP`/`DATE` literals consistent, and independent from the default time zone of current JVM.
Also this PR ports `TIMESTAMP`/`DATE` literals formatting on Proleptic Gregorian Calendar via using `TimestampFormatter`/`DateFormatter`.
## How was this patch tested?
Added new tests to `LiteralExpressionSuite`
Closes#24181 from MaxGekk/timezone-aware-literals.
Authored-by: Maxim Gekk <maxim.gekk@databricks.com>
Signed-off-by: Wenchen Fan <wenchen@databricks.com>
## What changes were proposed in this pull request?
In Spark 2.1, we hit a correctness bug. When reading a Hive serde parquet table with the native parquet data source, and the actual file schema doesn't match the table schema in Hive metastore(only upper/lower case difference), the query returns 0 results.
The reason is that, the parquet reader is case sensitive. If we push down filters with column names that don't match the file physical schema case-sensitively, no data will be returned.
To fix this bug, there were 2 solutions proposed at that time:
1. Add a config to optionally disable parquet filter pushdown, and make parquet column pruning case insensitive.
https://github.com/apache/spark/pull/16797
2. Infer the actual schema from data files, when reading Hive serde table with native data source. A config is provided to disable it.
https://github.com/apache/spark/pull/17229
Solution 2 was accepted and merged to Spark 2.1.1
In Spark 2.4, we refactored the parquet data source a little:
1. do parquet filter pushdown with the actual file schema.
https://github.com/apache/spark/pull/21696
2. make parquet filter pushdown case insensitive.
https://github.com/apache/spark/pull/22197
3. make parquet column pruning case insensitive.
https://github.com/apache/spark/pull/22148
With these patches, the correctness bug in Spark 2.1 no longer exists, and the schema inference becomes unnecessary.
To be safe, this PR just changes the default value to NEVER_INFER, so that users can set it back to INFER_AND_SAVE. If we don't receive any bug reports for it, we can remove the related code in the next release.
## How was this patch tested?
existing tests
Closes#24041 from cloud-fan/infer.
Authored-by: Wenchen Fan <wenchen@databricks.com>
Signed-off-by: gatorsmile <gatorsmile@gmail.com>
## What changes were proposed in this pull request?
In the PR, I propose to replace `System.currentTimeMillis()` by `Instant.now()` in the `CurrentTimestamp` expression. `Instant.now()` uses the best available clock in the system to take current time. See [JDK-8068730](https://bugs.openjdk.java.net/browse/JDK-8068730) for more details. In JDK8, `Instant.now()` provides results with millisecond resolution but starting from JDK9 resolution of results is increased up to microseconds.
## How was this patch tested?
The changes were tested by `DateTimeUtilsSuite` and by `DateFunctionsSuite`.
Closes#23945 from MaxGekk/current-time.
Authored-by: Maxim Gekk <max.gekk@gmail.com>
Signed-off-by: Sean Owen <sean.owen@databricks.com>
Hive 2.1.1 cannot read ORC table created by Spark 2.4.0 in default, and I add the information into sql-migration-guide-upgrade.md. for details to see: [SPARK-26932](https://issues.apache.org/jira/browse/SPARK-26932)
doc build
Closes#23944 from haiboself/SPARK-26932.
Authored-by: Bo Hai <haibo-self@163.com>
Signed-off-by: Dongjoon Hyun <dhyun@apple.com>
## What changes were proposed in this pull request?
In the PR, I propose to convert time zone string to `TimeZone` by converting it to `ZoneId` which uses `ZoneOffset` internally. The `ZoneOffset` class of JDK 8 has a cache already: http://hg.openjdk.java.net/jdk8/jdk8/jdk/file/687fd7c7986d/src/share/classes/java/time/ZoneOffset.java#l205 . In this way, there is no need to support cache of time zones in Spark.
The PR removes `computedTimeZones` from `DateTimeUtils`, and uses `ZoneId.of` to convert time zone id string to `ZoneId` and to `TimeZone` at the end.
## How was this patch tested?
The changes were tested by
Closes#23812 from MaxGekk/timezone-cache.
Lead-authored-by: Maxim Gekk <max.gekk@gmail.com>
Co-authored-by: Maxim Gekk <maxim.gekk@databricks.com>
Signed-off-by: Sean Owen <sean.owen@databricks.com>
## What changes were proposed in this pull request?
Collapsed notes about using Java 8 API for date/timestamp manipulations and Proleptic Gregorian calendar in the SQL migration guide.
Closes#23722 from MaxGekk/collapse-notes.
Authored-by: Maxim Gekk <max.gekk@gmail.com>
Signed-off-by: Hyukjin Kwon <gurwls223@apache.org>
## What changes were proposed in this pull request?
- Replacing `java.util.Calendar` in `DateTimeUtils. truncTimestamp` and in `DateTimeUtils.getOffsetFromLocalMillis ` by equivalent code using Java 8 API for timestamp manipulations. The reason is `java.util.Calendar` is based on the hybrid calendar (Julian+Gregorian) but *java.time* classes use Proleptic Gregorian calendar which assumes by SQL standard.
- Replacing `Calendar.getInstance()` in `DateTimeUtilsSuite` by similar code in `DateTimeTestUtils` using *java.time* classes
## How was this patch tested?
The changes were tested by existing suites: `DateExpressionsSuite`, `DateFunctionsSuite` and `DateTimeUtilsSuite`.
Closes#23641 from MaxGekk/cleanup-date-time-utils.
Authored-by: Maxim Gekk <maxim.gekk@databricks.com>
Signed-off-by: Sean Owen <sean.owen@databricks.com>
## What changes were proposed in this pull request?
In the PR, I propose using of the `stringToDate` and `stringToTimestamp` methods in parsing JDBC lower/upper bounds of the partition column if it has `DateType` or `TimestampType`. Since those methods have been ported on Proleptic Gregorian calendar by #23512, the PR switches parsing of JDBC bounds of the partition column on the calendar as well.
## How was this patch tested?
This was tested by `JDBCSuite`.
Closes#23597 from MaxGekk/jdbc-parse-timestamp-bounds.
Lead-authored-by: Maxim Gekk <maxim.gekk@databricks.com>
Co-authored-by: Maxim Gekk <max.gekk@gmail.com>
Signed-off-by: Wenchen Fan <wenchen@databricks.com>
## What changes were proposed in this pull request?
The expressions `DayWeek`, `DayOfWeek`, `WeekDay` and `WeekOfYear` are changed to use Proleptic Gregorian calendar instead of the hybrid one (Julian+Gregorian). This was achieved by using Java 8 API for date/timestamp manipulation, in particular the `LocalDate` class.
Week of year calculation is performed according to ISO-8601. The first week of a week-based-year is the first Monday-based week of the standard ISO year that has at least 4 days in the new year (see https://docs.oracle.com/javase/8/docs/api/java/time/temporal/IsoFields.html).
## How was this patch tested?
The changes were tested by `DateExpressionsSuite` and `DateFunctionsSuite`.
Closes#23594 from MaxGekk/dayweek-gregorian.
Lead-authored-by: Maxim Gekk <max.gekk@gmail.com>
Co-authored-by: Maxim Gekk <maxim.gekk@databricks.com>
Signed-off-by: Herman van Hovell <hvanhovell@databricks.com>
## What changes were proposed in this pull request?
Since 0.11.0, PyArrow supports to raise an error for unsafe cast ([PR](https://github.com/apache/arrow/pull/2504)). We should use it to raise a proper error for pandas udf users when such cast is detected.
Added a SQL config `spark.sql.execution.pandas.arrowSafeTypeConversion` to disable Arrow safe type check.
## How was this patch tested?
Added test and manually test.
Closes#22807 from viirya/SPARK-25811.
Authored-by: Liang-Chi Hsieh <viirya@gmail.com>
Signed-off-by: Hyukjin Kwon <gurwls223@apache.org>
## What changes were proposed in this pull request?
This PR reverts #22938 per discussion in #23325Closes#23325Closes#23543 from MaxGekk/return-nulls-from-json-parser.
Authored-by: Maxim Gekk <max.gekk@gmail.com>
Signed-off-by: Wenchen Fan <wenchen@databricks.com>
## What changes were proposed in this pull request?
The SQL config `spark.sql.legacy.timeParser.enabled` was removed by https://github.com/apache/spark/pull/23495. The PR cleans up the SQL migration guide and the comment for `UnixTimestamp`.
Closes#23529 from MaxGekk/get-rid-off-legacy-parser-followup.
Authored-by: Maxim Gekk <max.gekk@gmail.com>
Signed-off-by: Hyukjin Kwon <gurwls223@apache.org>
## What changes were proposed in this pull request?
In https://github.com/apache/spark/pull/22732 , we tried our best to keep the behavior of Scala UDF unchanged in Spark 2.4.
However, since Spark 3.0, Scala 2.12 is the default. The trick that was used to keep the behavior unchanged doesn't work with Scala 2.12.
This PR proposes to remove the Scala 2.11 hack, as it's not useful.
## How was this patch tested?
existing tests.
Closes#23498 from cloud-fan/udf.
Authored-by: Wenchen Fan <wenchen@databricks.com>
Signed-off-by: Wenchen Fan <wenchen@databricks.com>
## What changes were proposed in this pull request?
In https://github.com/apache/spark/pull/23043 , we introduced a behavior change: Spark users are not able to distinguish 0.0 and -0.0 anymore.
This PR proposes an alternative fix to the original bug, to retain the difference between 0.0 and -0.0 inside Spark.
The idea is, we can rewrite the window partition key, join key and grouping key during logical phase, to normalize the special floating numbers. Thus only operators care about special floating numbers need to pay the perf overhead, and end users can distinguish -0.0.
## How was this patch tested?
existing test
Closes#23388 from cloud-fan/minor.
Authored-by: Wenchen Fan <wenchen@databricks.com>
Signed-off-by: gatorsmile <gatorsmile@gmail.com>
## What changes were proposed in this pull request?
Fixed a few typos in the migration guide.
Closes#23465 from MaxGekk/fix-typos-migration-guide.
Authored-by: Maxim Gekk <max.gekk@gmail.com>
Signed-off-by: Hyukjin Kwon <gurwls223@apache.org>
## What changes were proposed in this pull request?
Added new JSON option `inferTimestamp` (`true` by default) to control inferring of `TimestampType` from string values.
## How was this patch tested?
Add new UT to `JsonInferSchemaSuite`.
Closes#23455 from MaxGekk/json-infer-time-followup.
Authored-by: Maxim Gekk <maxim.gekk@databricks.com>
Signed-off-by: Hyukjin Kwon <gurwls223@apache.org>
## What changes were proposed in this pull request?
In the PR, I propose to switch the `DateFormatClass`, `ToUnixTimestamp`, `FromUnixTime`, `UnixTime` on java.time API for parsing/formatting dates and timestamps. The API has been already implemented by the `Timestamp`/`DateFormatter` classes. One of benefit is those classes support parsing timestamps with microsecond precision. Old behaviour can be switched on via SQL config: `spark.sql.legacy.timeParser.enabled` (`false` by default).
## How was this patch tested?
It was tested by existing test suites - `DateFunctionsSuite`, `DateExpressionsSuite`, `JsonSuite`, `CsvSuite`, `SQLQueryTestSuite` as well as PySpark tests.
Closes#23358 from MaxGekk/new-time-cast.
Lead-authored-by: Maxim Gekk <maxim.gekk@databricks.com>
Co-authored-by: Maxim Gekk <max.gekk@gmail.com>
Signed-off-by: Wenchen Fan <wenchen@databricks.com>
## What changes were proposed in this pull request?
A followup of https://github.com/apache/spark/pull/23178 , to keep binary compability by using abstract class.
## How was this patch tested?
Manual test. I created a simple app with Spark 2.4
```
object TryUDF {
def main(args: Array[String]): Unit = {
val spark = SparkSession.builder().appName("test").master("local[*]").getOrCreate()
import spark.implicits._
val f1 = udf((i: Int) => i + 1)
println(f1.deterministic)
spark.range(10).select(f1.asNonNullable().apply($"id")).show()
spark.stop()
}
}
```
When I run it with current master, it fails with
```
java.lang.IncompatibleClassChangeError: Found interface org.apache.spark.sql.expressions.UserDefinedFunction, but class was expected
```
When I run it with this PR, it works
Closes#23351 from cloud-fan/minor.
Authored-by: Wenchen Fan <wenchen@databricks.com>
Signed-off-by: Wenchen Fan <wenchen@databricks.com>
## What changes were proposed in this pull request?
In the PR, I propose to switch on **java.time API** for parsing timestamps and dates from JSON inputs with microseconds precision. The SQL config `spark.sql.legacy.timeParser.enabled` allow to switch back to previous behavior with using `java.text.SimpleDateFormat`/`FastDateFormat` for parsing/generating timestamps/dates.
## How was this patch tested?
It was tested by `JsonExpressionsSuite`, `JsonFunctionsSuite` and `JsonSuite`.
Closes#23196 from MaxGekk/json-time-parser.
Lead-authored-by: Maxim Gekk <maxim.gekk@databricks.com>
Co-authored-by: Maxim Gekk <max.gekk@gmail.com>
Signed-off-by: Wenchen Fan <wenchen@databricks.com>
## What changes were proposed in this pull request?
In the PR, I propose to return partial results from JSON datasource and JSON functions in the PERMISSIVE mode if some of JSON fields are parsed and converted to desired types successfully. The changes are made only for `StructType`. Whole bad JSON records are placed into the corrupt column specified by the `columnNameOfCorruptRecord` option or SQL config.
Partial results are not returned for malformed JSON input.
## How was this patch tested?
Added new UT which checks converting JSON strings with one invalid and one valid field at the end of the string.
Closes#23253 from MaxGekk/json-bad-record.
Lead-authored-by: Maxim Gekk <max.gekk@gmail.com>
Co-authored-by: Maxim Gekk <maxim.gekk@databricks.com>
Signed-off-by: Hyukjin Kwon <gurwls223@apache.org>
## What changes were proposed in this pull request?
#22148 introduces a behavior change. According to discussion at #22184, this PR updates migration guide when upgrade from Spark 2.3 to 2.4.
## How was this patch tested?
N/A
Closes#23238 from seancxmao/SPARK-25132-doc-2.4.
Authored-by: seancxmao <seancxmao@gmail.com>
Signed-off-by: Dongjoon Hyun <dongjoon@apache.org>
## What changes were proposed in this pull request?
This is a follow-up of #23031 to rename the config name to `spark.sql.legacy.setCommandRejectsSparkCoreConfs`.
## How was this patch tested?
Existing tests.
Closes#23245 from ueshin/issues/SPARK-26060/rename_config.
Authored-by: Takuya UESHIN <ueshin@databricks.com>
Signed-off-by: Dongjoon Hyun <dongjoon@apache.org>
## What changes were proposed in this pull request?
Currently if user provides data schema, partition column values are converted as per it. But if the conversion failed, e.g. converting string to int, the column value is null.
This PR proposes to throw exception in such case, instead of converting into null value silently:
1. These null partition column values doesn't make sense to users in most cases. It is better to show the conversion failure, and then users can adjust the schema or ETL jobs to fix it.
2. There are always exceptions on such conversion failure for non-partition data columns. Partition columns should have the same behavior.
We can reproduce the case above as following:
```
/tmp/testDir
├── p=bar
└── p=foo
```
If we run:
```
val schema = StructType(Seq(StructField("p", IntegerType, false)))
spark.read.schema(schema).csv("/tmp/testDir/").show()
```
We will get:
```
+----+
| p|
+----+
|null|
|null|
+----+
```
## How was this patch tested?
Unit test
Closes#23215 from gengliangwang/SPARK-26263.
Authored-by: Gengliang Wang <gengliang.wang@databricks.com>
Signed-off-by: Wenchen Fan <wenchen@databricks.com>
## What changes were proposed in this pull request?
Updated SQL migration guide according to changes in https://github.com/apache/spark/pull/23120Closes#23235 from MaxGekk/failuresafe-partial-result-followup.
Lead-authored-by: Maxim Gekk <maxim.gekk@databricks.com>
Co-authored-by: Maxim Gekk <max.gekk@gmail.com>
Signed-off-by: Wenchen Fan <wenchen@databricks.com>
## What changes were proposed in this pull request?
In the PR, I propose to use **java.time API** for parsing timestamps and dates from CSV content with microseconds precision. The SQL config `spark.sql.legacy.timeParser.enabled` allow to switch back to previous behaviour with using `java.text.SimpleDateFormat`/`FastDateFormat` for parsing/generating timestamps/dates.
## How was this patch tested?
It was tested by `UnivocityParserSuite`, `CsvExpressionsSuite`, `CsvFunctionsSuite` and `CsvSuite`.
Closes#23150 from MaxGekk/time-parser.
Lead-authored-by: Maxim Gekk <max.gekk@gmail.com>
Co-authored-by: Maxim Gekk <maxim.gekk@databricks.com>
Signed-off-by: Sean Owen <sean.owen@databricks.com>
## What changes were proposed in this pull request?
It's a bad idea to use case class as public API, as it has a very wide surface. For example, the `copy` method, its fields, the companion object, etc.
For a particular case, `UserDefinedFunction`. It has a private constructor, and I believe we only want users to access a few methods:`apply`, `nullable`, `asNonNullable`, etc.
However, all its fields, and `copy` method, and the companion object are public unexpectedly. As a result, we made many tricks to work around the binary compatibility issues.
This PR proposes to only make interfaces public, and hide implementations behind with a private class. Now `UserDefinedFunction` is a pure trait, and the concrete implementation is `SparkUserDefinedFunction`, which is private.
Changing class to interface is not binary compatible(but source compatible), so 3.0 is a good chance to do it.
This is the first PR to go with this direction. If it's accepted, I'll create a umbrella JIRA and fix all the public case classes.
## How was this patch tested?
existing tests.
Closes#23178 from cloud-fan/udf.
Authored-by: Wenchen Fan <wenchen@databricks.com>
Signed-off-by: Wenchen Fan <wenchen@databricks.com>
## What changes were proposed in this pull request?
Currently the `SET` command works without any warnings even if the specified key is for `SparkConf` entries and it has no effect because the command does not update `SparkConf`, but the behavior might confuse users. We should track `SparkConf` entries and make the command reject for such entries.
## How was this patch tested?
Added a test and existing tests.
Closes#23031 from ueshin/issues/SPARK-26060/set_command.
Authored-by: Takuya UESHIN <ueshin@databricks.com>
Signed-off-by: Wenchen Fan <wenchen@databricks.com>
## What changes were proposed in this pull request?
Currently duplicated map keys are not handled consistently. For example, map look up respects the duplicated key appears first, `Dataset.collect` only keeps the duplicated key appears last, `MapKeys` returns duplicated keys, etc.
This PR proposes to remove duplicated map keys with last wins policy, to follow Java/Scala and Presto. It only applies to built-in functions, as users can create map with duplicated map keys via private APIs anyway.
updated functions: `CreateMap`, `MapFromArrays`, `MapFromEntries`, `StringToMap`, `MapConcat`, `TransformKeys`.
For other places:
1. data source v1 doesn't have this problem, as users need to provide a java/scala map, which can't have duplicated keys.
2. data source v2 may have this problem. I've added a note to `ArrayBasedMapData` to ask the caller to take care of duplicated keys. In the future we should enforce it in the stable data APIs for data source v2.
3. UDF doesn't have this problem, as users need to provide a java/scala map. Same as data source v1.
4. file format. I checked all of them and only parquet does not enforce it. For backward compatibility reasons I change nothing but leave a note saying that the behavior will be undefined if users write map with duplicated keys to parquet files. Maybe we can add a config and fail by default if parquet files have map with duplicated keys. This can be done in followup.
## How was this patch tested?
updated tests and new tests
Closes#23124 from cloud-fan/map.
Authored-by: Wenchen Fan <wenchen@databricks.com>
Signed-off-by: Wenchen Fan <wenchen@databricks.com>
## What changes were proposed in this pull request?
a followup of https://github.com/apache/spark/pull/23043 . Add a test to show the minor behavior change introduced by #23043 , and add migration guide.
## How was this patch tested?
a new test
Closes#23141 from cloud-fan/follow.
Authored-by: Wenchen Fan <wenchen@databricks.com>
Signed-off-by: Wenchen Fan <wenchen@databricks.com>
## What changes were proposed in this pull request?
This PR is to add back `unionAll`, which is widely used. The name is also consistent with our ANSI SQL. We also have the corresponding `intersectAll` and `exceptAll`, which were introduced in Spark 2.4.
## How was this patch tested?
Added a test case in DataFrameSuite
Closes#23131 from gatorsmile/addBackUnionAll.
Authored-by: gatorsmile <gatorsmile@gmail.com>
Signed-off-by: gatorsmile <gatorsmile@gmail.com>
## What changes were proposed in this pull request?
When doing typed aggregation on a Dataset, for struct key type, the key attribute is named as "key". But for non-struct type, the key attribute is named as "value". This key attribute should also be named as "key" for non-struct type.
## How was this patch tested?
Added test.
Closes#23054 from viirya/SPARK-26085.
Authored-by: Liang-Chi Hsieh <viirya@gmail.com>
Signed-off-by: Wenchen Fan <wenchen@databricks.com>
## What changes were proposed in this pull request?
An input without valid JSON tokens on the root level will be treated as a bad record, and handled according to `mode`. Previously such input was converted to `null`. After the changes, the input is converted to a row with `null`s in the `PERMISSIVE` mode according the schema. This allows to remove a code in the `from_json` function which can produce `null` as result rows.
## How was this patch tested?
It was tested by existing test suites. Some of them I have to modify (`JsonSuite` for example) because previously bad input was just silently ignored. For now such input is handled according to specified `mode`.
Closes#22938 from MaxGekk/json-nulls.
Lead-authored-by: Maxim Gekk <max.gekk@gmail.com>
Co-authored-by: Maxim Gekk <maxim.gekk@databricks.com>
Signed-off-by: Wenchen Fan <wenchen@databricks.com>
## What changes were proposed in this pull request?
Due to implementation limitation, currently Spark can't compare or do equality check between map types. As a result, map values can't appear in EQUAL or comparison expressions, can't be grouping key, etc.
The more important thing is, map loop up needs to do equality check of the map key, and thus can't support map as map key when looking up values from a map. Thus it's not useful to have map as map key.
This PR proposes to stop users from creating maps using map type as key. The list of expressions that are updated: `CreateMap`, `MapFromArrays`, `MapFromEntries`, `MapConcat`, `TransformKeys`. I manually checked all the places that create `MapType`, and came up with this list.
Note that, maps with map type key still exist, via reading from parquet files, converting from scala/java map, etc. This PR is not to completely forbid map as map key, but to avoid creating it by Spark itself.
Motivation: when I was trying to fix the duplicate key problem, I found it's impossible to do it with map type map key. I think it's reasonable to avoid map type map key for builtin functions.
## How was this patch tested?
updated test
Closes#23045 from cloud-fan/map-key.
Authored-by: Wenchen Fan <wenchen@databricks.com>
Signed-off-by: Wenchen Fan <wenchen@databricks.com>
## What changes were proposed in this pull request?
Fix typos and misspellings, per https://github.com/apache/spark-website/pull/158#issuecomment-435790366
## How was this patch tested?
Existing tests.
Closes#22950 from srowen/Typos.
Authored-by: Sean Owen <sean.owen@databricks.com>
Signed-off-by: Sean Owen <sean.owen@databricks.com>
## What changes were proposed in this pull request?
Add note about AddJar return value change in migration guide
## How was this patch tested?
n/a
Closes#22826 from srowen/SPARK-25760.2.
Authored-by: Sean Owen <sean.owen@databricks.com>
Signed-off-by: Sean Owen <sean.owen@databricks.com>
## What changes were proposed in this pull request?
Since Spark 2.2, view definitions are stored in a different way from prior versions. This may cause Spark unable to read views created by prior versions. See [SPARK-25797](https://issues.apache.org/jira/browse/SPARK-25797) for more details.
Basically, we have 2 options.
1) Make Spark 2.2+ able to get older view definitions back. Since the expanded text is buggy and unusable, we have to use original text (this is possible with [SPARK-25459](https://issues.apache.org/jira/browse/SPARK-25459)). However, because older Spark versions don't save the context for the database, we cannot always get correct view definitions without view default database.
2) Recreate the views by `ALTER VIEW AS` or `CREATE OR REPLACE VIEW AS`.
This PR aims to add migration doc to help users troubleshoot this issue by above option 2.
## How was this patch tested?
N/A.
Docs are generated and checked locally
```
cd docs
SKIP_API=1 jekyll serve --watch
```
Closes#22846 from seancxmao/SPARK-25797.
Authored-by: seancxmao <seancxmao@gmail.com>
Signed-off-by: Wenchen Fan <wenchen@databricks.com>
## What changes were proposed in this pull request?
In the PR, I propose to switch `from_json` on `FailureSafeParser`, and to make the function compatible to `PERMISSIVE` mode by default, and to support the `FAILFAST` mode as well. The `DROPMALFORMED` mode is not supported by `from_json`.
## How was this patch tested?
It was tested by existing `JsonSuite`/`CSVSuite`, `JsonFunctionsSuite` and `JsonExpressionsSuite` as well as new tests for `from_json` which checks different modes.
Closes#22237 from MaxGekk/from_json-failuresafe.
Lead-authored-by: Maxim Gekk <maxim.gekk@databricks.com>
Co-authored-by: hyukjinkwon <gurwls223@apache.org>
Signed-off-by: Wenchen Fan <wenchen@databricks.com>
## What changes were proposed in this pull request?
This takes over original PR at #22019. The original proposal is to have null for float and double types. Later a more reasonable proposal is to disallow empty strings. This patch adds logic to throw exception when finding empty strings for non string types.
## How was this patch tested?
Added test.
Closes#22787 from viirya/SPARK-25040.
Authored-by: Liang-Chi Hsieh <viirya@gmail.com>
Signed-off-by: hyukjinkwon <gurwls223@apache.org>
## What changes were proposed in this pull request?
1. Split the main page of sql-programming-guide into 7 parts:
- Getting Started
- Data Sources
- Performance Turing
- Distributed SQL Engine
- PySpark Usage Guide for Pandas with Apache Arrow
- Migration Guide
- Reference
2. Add left menu for sql-programming-guide, keep first level index for each part in the menu.
## How was this patch tested?
Local test with jekyll build/serve.
Closes#22746 from xuanyuanking/SPARK-24499.
Authored-by: Yuanjian Li <xyliyuanjian@gmail.com>
Signed-off-by: gatorsmile <gatorsmile@gmail.com>
