spark-instrumented-optimizer/sql
Max Gekk 5d5866be12 [SPARK-31672][SQL] Fix loading of timestamps before 1582-10-15 from dictionary encoded Parquet columns
### What changes were proposed in this pull request?
Modified the `decodeDictionaryIds()` method of `VectorizedColumnReader` to handle especially `TimestampType` when the passed parameter `rebaseDateTime` is true. In that case, decoded milliseconds/microseconds are rebased from the hybrid calendar to Proleptic Gregorian calendar using `RebaseDateTime`.`rebaseJulianToGregorianMicros()`.

### Why are the changes needed?
This fixes the bug of loading timestamps before the cutover day from dictionary encoded column in parquet files. The code below forces dictionary encoding:
```scala
spark.conf.set("spark.sql.legacy.parquet.rebaseDateTimeInWrite.enabled", true)
scala> spark.conf.set("spark.sql.parquet.outputTimestampType", "TIMESTAMP_MICROS")
scala>
Seq.tabulate(8)(_ => "1001-01-01 01:02:03.123").toDF("tsS")
  .select($"tsS".cast("timestamp").as("ts")).repartition(1)
  .write
  .option("parquet.enable.dictionary", true)
  .parquet(path)
```
Load the dates back:
```scala
scala> spark.read.parquet(path).show(false)
+-----------------------+
|ts                     |
+-----------------------+
|1001-01-07 00:32:20.123|
...
|1001-01-07 00:32:20.123|
+-----------------------+
```
Expected values **must be 1001-01-01 01:02:03.123** but not 1001-01-07 00:32:20.123.

### Does this PR introduce _any_ user-facing change?
Yes. After the changes:
```scala
scala> spark.read.parquet(path).show(false)
+-----------------------+
|ts                     |
+-----------------------+
|1001-01-01 01:02:03.123|
...
|1001-01-01 01:02:03.123|
+-----------------------+
```

### How was this patch tested?
Modified the test `SPARK-31159: rebasing timestamps in write` in `ParquetIOSuite` to checked reading dictionary encoded dates.

Closes #28489 from MaxGekk/fix-ts-rebase-parquet-dict-enc.

Authored-by: Max Gekk <max.gekk@gmail.com>
Signed-off-by: Wenchen Fan <wenchen@databricks.com>
2020-05-11 04:58:08 +00:00
..
catalyst [SPARK-31669][SQL][TESTS] Fix RowEncoderSuite failures on non-existing dates/timestamps 2020-05-10 14:22:12 -05:00
core [SPARK-31672][SQL] Fix loading of timestamps before 1582-10-15 from dictionary encoded Parquet columns 2020-05-11 04:58:08 +00:00
hive [SPARK-31467][SQL][TEST] Refactor the sql tests to prevent TableAlreadyExistsException 2020-05-05 15:14:33 +09:00
hive-thriftserver [SPARK-31595][SQL] Spark sql should allow unescaped quote mark in quoted string 2020-05-06 04:34:43 +00:00
create-docs.sh [SPARK-31550][SQL][DOCS] Set nondeterministic configurations with general meanings in sql configuration doc 2020-04-27 17:08:52 +09:00
gen-sql-api-docs.py [SPARK-31474][SQL][FOLLOWUP] Replace _FUNC_ placeholder with functionname in the note field of expression info 2020-04-23 13:33:04 +09:00
gen-sql-config-docs.py [SPARK-31550][SQL][DOCS] Set nondeterministic configurations with general meanings in sql configuration doc 2020-04-27 17:08:52 +09:00
gen-sql-functions-docs.py [SPARK-31562][SQL] Update ExpressionDescription for substring, current_date, and current_timestamp 2020-04-26 11:46:52 -07:00
mkdocs.yml [SPARK-30731] Update deprecated Mkdocs option 2020-02-19 17:28:58 +09:00
README.md [SPARK-30510][SQL][DOCS] Publicly document Spark SQL configuration options 2020-02-09 19:20:47 +09:00

Spark SQL

This module provides support for executing relational queries expressed in either SQL or the DataFrame/Dataset API.

Spark SQL is broken up into four subprojects:

  • Catalyst (sql/catalyst) - An implementation-agnostic framework for manipulating trees of relational operators and expressions.
  • Execution (sql/core) - A query planner / execution engine for translating Catalyst's logical query plans into Spark RDDs. This component also includes a new public interface, SQLContext, that allows users to execute SQL or LINQ statements against existing RDDs and Parquet files.
  • Hive Support (sql/hive) - Includes extensions that allow users to write queries using a subset of HiveQL and access data from a Hive Metastore using Hive SerDes. There are also wrappers that allow users to run queries that include Hive UDFs, UDAFs, and UDTFs.
  • HiveServer and CLI support (sql/hive-thriftserver) - Includes support for the SQL CLI (bin/spark-sql) and a HiveServer2 (for JDBC/ODBC) compatible server.

Running ./sql/create-docs.sh generates SQL documentation for built-in functions under sql/site, and SQL configuration documentation that gets included as part of configuration.md in the main docs directory.