You are viewing a plain text version of this content. The canonical link for it is here.
Posted to reviews@spark.apache.org by "cloud-fan (via GitHub)" <gi...@apache.org> on 2024/01/19 11:20:01 UTC
[PR] [SPARK-46769][SQL] Refine timestamp related schema inference [spark]
cloud-fan opened a new pull request, #44800:
URL: https://github.com/apache/spark/pull/44800
<!--
Thanks for sending a pull request! Here are some tips for you:
1. If this is your first time, please read our contributor guidelines: https://spark.apache.org/contributing.html
2. Ensure you have added or run the appropriate tests for your PR: https://spark.apache.org/developer-tools.html
3. If the PR is unfinished, add '[WIP]' in your PR title, e.g., '[WIP][SPARK-XXXX] Your PR title ...'.
4. Be sure to keep the PR description updated to reflect all changes.
5. Please write your PR title to summarize what this PR proposes.
6. If possible, provide a concise example to reproduce the issue for a faster review.
7. If you want to add a new configuration, please read the guideline first for naming configurations in
'core/src/main/scala/org/apache/spark/internal/config/ConfigEntry.scala'.
8. If you want to add or modify an error type or message, please read the guideline first in
'core/src/main/resources/error/README.md'.
-->
### What changes were proposed in this pull request?
<!--
Please clarify what changes you are proposing. The purpose of this section is to outline the changes and how this PR fixes the issue.
If possible, please consider writing useful notes for better and faster reviews in your PR. See the examples below.
1. If you refactor some codes with changing classes, showing the class hierarchy will help reviewers.
2. If you fix some SQL features, you can provide some references of other DBMSes.
3. If there is design documentation, please add the link.
4. If there is a discussion in the mailing list, please add the link.
-->
This is a refinement of https://github.com/apache/spark/pull/43243 . This PR enforces one thing: we only infer TIMESTAMP NTZ type using NTZ parser, and only infer LTZ type using LTZ parser. This consistency is important to avoid potential bugs.
### Why are the changes needed?
<!--
Please clarify why the changes are needed. For instance,
1. If you propose a new API, clarify the use case for a new API.
2. If you fix a bug, you can clarify why it is a bug.
-->
Avoid potential bugs. After https://github.com/apache/spark/pull/43243 , we can still have inconsistency if the LEGACY mode is enabled.
### Does this PR introduce _any_ user-facing change?
<!--
Note that it means *any* user-facing change including all aspects such as the documentation fix.
If yes, please clarify the previous behavior and the change this PR proposes - provide the console output, description and/or an example to show the behavior difference if possible.
If possible, please also clarify if this is a user-facing change compared to the released Spark versions or within the unreleased branches such as master.
If no, write 'No'.
-->
No
### How was this patch tested?
<!--
If tests were added, say they were added here. Please make sure to add some test cases that check the changes thoroughly including negative and positive cases if possible.
If it was tested in a way different from regular unit tests, please clarify how you tested step by step, ideally copy and paste-able, so that other reviewers can test and check, and descendants can verify in the future.
If tests were not added, please describe why they were not added and/or why it was difficult to add.
If benchmark tests were added, please run the benchmarks in GitHub Actions for the consistent environment, and the instructions could accord to: https://spark.apache.org/developer-tools.html#github-workflow-benchmarks.
-->
existing tests
### Was this patch authored or co-authored using generative AI tooling?
<!--
If generative AI tooling has been used in the process of authoring this patch, please include the
phrase: 'Generated-by: ' followed by the name of the tool and its version.
If no, write 'No'.
Please refer to the [ASF Generative Tooling Guidance](https://www.apache.org/legal/generative-tooling.html) for details.
-->
no
--
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: reviews-unsubscribe@spark.apache.org
For queries about this service, please contact Infrastructure at:
users@infra.apache.org
---------------------------------------------------------------------
To unsubscribe, e-mail: reviews-unsubscribe@spark.apache.org
For additional commands, e-mail: reviews-help@spark.apache.org
Re: [PR] [SPARK-46769][SQL] Refine timestamp related schema inference [spark]
Posted by "cloud-fan (via GitHub)" <gi...@apache.org>.
cloud-fan commented on code in PR #44800:
URL: https://github.com/apache/spark/pull/44800#discussion_r1460152048
##########
sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/json/JsonInferSchema.scala:
##########
@@ -159,16 +161,28 @@ class JsonInferSchema(options: JSONOptions) extends Serializable with Logging {
val bigDecimal = decimalParser(field)
DecimalType(bigDecimal.precision, bigDecimal.scale)
}
- val timestampType = SQLConf.get.timestampType
if (options.prefersDecimal && decimalTry.isDefined) {
decimalTry.get
- } else if (options.inferTimestamp && (SQLConf.get.legacyTimeParserPolicy ==
- LegacyBehaviorPolicy.LEGACY || timestampType == TimestampNTZType) &&
+ } else if (options.inferTimestamp) {
+ // For text-based format, it's ambiguous to infer a timestamp string without timezone, as
+ // it can be both TIMESTAMP LTZ and NTZ. To avoid behavior changes with the new support
+ // of NTZ, here we only try to infer NTZ if the config is set to use NTZ by default.
+ if (isDefaultNTZ &&
timestampNTZFormatter.parseWithoutTimeZoneOptional(field, false).isDefined) {
- timestampType
- } else if (options.inferTimestamp &&
- timestampFormatter.parseOptional(field).isDefined) {
- TimestampType
+ TimestampNTZType
+ } else if (timestampFormatter.parseOptional(field).isDefined) {
+ TimestampType
+ } else {
+ val utf8Value = UTF8String.fromString(field)
+ // There was a mistake that we use TIMESTAMP NTZ parser to infer LTZ type.
+ // The mistake makes it easier to infer TIMESTAMP LTZ type and we have to keep this
+ // behavior now. See SPARK-46769 for more details.
+ if (SparkDateTimeUtils.stringToTimestampWithoutTimeZone(utf8Value, false).isDefined) {
Review Comment:
@gengliangwang
--
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: reviews-unsubscribe@spark.apache.org
For queries about this service, please contact Infrastructure at:
users@infra.apache.org
---------------------------------------------------------------------
To unsubscribe, e-mail: reviews-unsubscribe@spark.apache.org
For additional commands, e-mail: reviews-help@spark.apache.org
Re: [PR] [SPARK-46769][SQL] Refine timestamp related schema inference [spark]
Posted by "cloud-fan (via GitHub)" <gi...@apache.org>.
cloud-fan closed pull request #44800: [SPARK-46769][SQL] Refine timestamp related schema inference
URL: https://github.com/apache/spark/pull/44800
--
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: reviews-unsubscribe@spark.apache.org
For queries about this service, please contact Infrastructure at:
users@infra.apache.org
---------------------------------------------------------------------
To unsubscribe, e-mail: reviews-unsubscribe@spark.apache.org
For additional commands, e-mail: reviews-help@spark.apache.org
Re: [PR] [SPARK-46769][SQL] Refine timestamp related schema inference [spark]
Posted by "cloud-fan (via GitHub)" <gi...@apache.org>.
cloud-fan commented on code in PR #44800:
URL: https://github.com/apache/spark/pull/44800#discussion_r1459237229
##########
sql/core/src/test/scala/org/apache/spark/sql/execution/datasources/csv/CSVSuite.scala:
##########
@@ -2874,13 +2885,12 @@ abstract class CSVSuite
test("SPARK-40474: Infer schema for columns with a mix of dates and timestamp") {
withTempPath { path =>
- Seq(
- "1765-03-28",
+ val input = Seq(
"1423-11-12T23:41:00",
+ "1765-03-28",
Review Comment:
ditto, the latest master branch will fail this test if we move the first value to second, because only the first value will be inferred using NTZ parser, and the legacy timestamp parser can't parse date string.
--
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: reviews-unsubscribe@spark.apache.org
For queries about this service, please contact Infrastructure at:
users@infra.apache.org
---------------------------------------------------------------------
To unsubscribe, e-mail: reviews-unsubscribe@spark.apache.org
For additional commands, e-mail: reviews-help@spark.apache.org
Re: [PR] [SPARK-46769][SQL] Refine timestamp related schema inference [spark]
Posted by "cloud-fan (via GitHub)" <gi...@apache.org>.
cloud-fan commented on code in PR #44800:
URL: https://github.com/apache/spark/pull/44800#discussion_r1459232548
##########
sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/csv/CSVInferSchema.scala:
##########
@@ -199,14 +201,13 @@ class CSVInferSchema(val options: CSVOptions) extends Serializable {
}
private def tryParseTimestampNTZ(field: String): DataType = {
- // We can only parse the value as TimestampNTZType if it does not have zone-offset or
- // time-zone component and can be parsed with the timestamp formatter.
- // Otherwise, it is likely to be a timestamp with timezone.
- val timestampType = SQLConf.get.timestampType
- if ((SQLConf.get.legacyTimeParserPolicy == LegacyBehaviorPolicy.LEGACY ||
- timestampType == TimestampNTZType) &&
- timestampNTZFormatter.parseWithoutTimeZoneOptional(field, false).isDefined) {
- timestampType
Review Comment:
Schema inference is incremental. If we infer LTZ here, the next value will be parsed by `tryParseTimestamp` instead of `tryParseTimestampNTZ`. This is very confusing as the first value matters for the final inferred type.
--
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: reviews-unsubscribe@spark.apache.org
For queries about this service, please contact Infrastructure at:
users@infra.apache.org
---------------------------------------------------------------------
To unsubscribe, e-mail: reviews-unsubscribe@spark.apache.org
For additional commands, e-mail: reviews-help@spark.apache.org
Re: [PR] [SPARK-46769][SQL] Refine timestamp related schema inference [spark]
Posted by "Hisoka-X (via GitHub)" <gi...@apache.org>.
Hisoka-X commented on PR #44800:
URL: https://github.com/apache/spark/pull/44800#issuecomment-1900245476
The change seems like can not pass `CSVLegacyTimeParserSuite.SPARK-37326: Timestamp type inference for a column with TIMESTAMP_NTZ`. (Maybe because I used old version code)
--
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: reviews-unsubscribe@spark.apache.org
For queries about this service, please contact Infrastructure at:
users@infra.apache.org
---------------------------------------------------------------------
To unsubscribe, e-mail: reviews-unsubscribe@spark.apache.org
For additional commands, e-mail: reviews-help@spark.apache.org
Re: [PR] [SPARK-46769][SQL] Refine timestamp related schema inference [spark]
Posted by "cloud-fan (via GitHub)" <gi...@apache.org>.
cloud-fan commented on code in PR #44800:
URL: https://github.com/apache/spark/pull/44800#discussion_r1460150835
##########
sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/json/JsonInferSchema.scala:
##########
@@ -159,16 +161,28 @@ class JsonInferSchema(options: JSONOptions) extends Serializable with Logging {
val bigDecimal = decimalParser(field)
DecimalType(bigDecimal.precision, bigDecimal.scale)
}
- val timestampType = SQLConf.get.timestampType
if (options.prefersDecimal && decimalTry.isDefined) {
decimalTry.get
- } else if (options.inferTimestamp && (SQLConf.get.legacyTimeParserPolicy ==
- LegacyBehaviorPolicy.LEGACY || timestampType == TimestampNTZType) &&
+ } else if (options.inferTimestamp) {
+ // For text-based format, it's ambiguous to infer a timestamp string without timezone, as
+ // it can be both TIMESTAMP LTZ and NTZ. To avoid behavior changes with the new support
+ // of NTZ, here we only try to infer NTZ if the config is set to use NTZ by default.
+ if (isDefaultNTZ &&
timestampNTZFormatter.parseWithoutTimeZoneOptional(field, false).isDefined) {
- timestampType
- } else if (options.inferTimestamp &&
- timestampFormatter.parseOptional(field).isDefined) {
- TimestampType
+ TimestampNTZType
+ } else if (timestampFormatter.parseOptional(field).isDefined) {
+ TimestampType
+ } else {
+ val utf8Value = UTF8String.fromString(field)
+ // There was a mistake that we use TIMESTAMP NTZ parser to infer LTZ type.
+ // The mistake makes it easier to infer TIMESTAMP LTZ type and we have to keep this
+ // behavior now. See SPARK-46769 for more details.
+ if (SparkDateTimeUtils.stringToTimestampWithoutTimeZone(utf8Value, false).isDefined) {
Review Comment:
In JSON, schema inference is not incremental but always start from beginning. That said, the first value doesn't matter. To avoid breaking change, I choose to keep the existing behavior in a less hacky way. This if condition is how the default NTZ parser works, which is more stable as previously the LTZ inference behavior is controlled by the option `timestampNTZFormat`
--
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: reviews-unsubscribe@spark.apache.org
For queries about this service, please contact Infrastructure at:
users@infra.apache.org
---------------------------------------------------------------------
To unsubscribe, e-mail: reviews-unsubscribe@spark.apache.org
For additional commands, e-mail: reviews-help@spark.apache.org
Re: [PR] [SPARK-46769][SQL] Refine timestamp related schema inference [spark]
Posted by "gengliangwang (via GitHub)" <gi...@apache.org>.
gengliangwang commented on code in PR #44800:
URL: https://github.com/apache/spark/pull/44800#discussion_r1459496728
##########
sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/json/JsonInferSchema.scala:
##########
@@ -159,16 +160,21 @@ class JsonInferSchema(options: JSONOptions) extends Serializable with Logging {
val bigDecimal = decimalParser(field)
DecimalType(bigDecimal.precision, bigDecimal.scale)
}
- val timestampType = SQLConf.get.timestampType
if (options.prefersDecimal && decimalTry.isDefined) {
decimalTry.get
- } else if (options.inferTimestamp && (SQLConf.get.legacyTimeParserPolicy ==
- LegacyBehaviorPolicy.LEGACY || timestampType == TimestampNTZType) &&
+ } else if (options.inferTimestamp) {
+ // For text-based format, it's ambiguous to infer a timestamp string without timezone, as
+ // it can be both TIMESTAMP LTZ and NTZ. To avoid behavior changes with the new support
+ // of NTZ, here we only try to infer NTZ if the config is set to use NTZ by default, or
+ // the NTZ timestamp format is set in the parsing options.
+ if ((isDefaultNTZ || options.timestampNTZFormatInRead.isDefined) &&
Review Comment:
This seems to be a behavior change. Before this PR, `options.timestampNTZFormatInRead` doesn't affect the inference result. Shall we simply make the condition as
```
if (isDefaultNTZ && timestampNTZFormatter.parseWithoutTimeZoneOptional(field, false).isDefined)
```
--
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: reviews-unsubscribe@spark.apache.org
For queries about this service, please contact Infrastructure at:
users@infra.apache.org
---------------------------------------------------------------------
To unsubscribe, e-mail: reviews-unsubscribe@spark.apache.org
For additional commands, e-mail: reviews-help@spark.apache.org
Re: [PR] [SPARK-46769][SQL] Refine timestamp related schema inference [spark]
Posted by "cloud-fan (via GitHub)" <gi...@apache.org>.
cloud-fan commented on code in PR #44800:
URL: https://github.com/apache/spark/pull/44800#discussion_r1460159595
##########
sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/json/JsonInferSchema.scala:
##########
@@ -159,16 +161,28 @@ class JsonInferSchema(options: JSONOptions) extends Serializable with Logging {
val bigDecimal = decimalParser(field)
DecimalType(bigDecimal.precision, bigDecimal.scale)
}
- val timestampType = SQLConf.get.timestampType
if (options.prefersDecimal && decimalTry.isDefined) {
decimalTry.get
- } else if (options.inferTimestamp && (SQLConf.get.legacyTimeParserPolicy ==
- LegacyBehaviorPolicy.LEGACY || timestampType == TimestampNTZType) &&
+ } else if (options.inferTimestamp) {
+ // For text-based format, it's ambiguous to infer a timestamp string without timezone, as
+ // it can be both TIMESTAMP LTZ and NTZ. To avoid behavior changes with the new support
+ // of NTZ, here we only try to infer NTZ if the config is set to use NTZ by default.
+ if (isDefaultNTZ &&
timestampNTZFormatter.parseWithoutTimeZoneOptional(field, false).isDefined) {
- timestampType
- } else if (options.inferTimestamp &&
- timestampFormatter.parseOptional(field).isDefined) {
- TimestampType
+ TimestampNTZType
+ } else if (timestampFormatter.parseOptional(field).isDefined) {
+ TimestampType
+ } else {
+ val utf8Value = UTF8String.fromString(field)
+ // There was a mistake that we use TIMESTAMP NTZ parser to infer LTZ type.
+ // The mistake makes it easier to infer TIMESTAMP LTZ type and we have to keep this
+ // behavior now. See SPARK-46769 for more details.
+ if (SparkDateTimeUtils.stringToTimestampWithoutTimeZone(utf8Value, false).isDefined) {
Review Comment:
`SparkDateTimeUtils.stringToTimestampWithoutTimeZone` is safer here because it's what the default NTZ parser does.
--
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: reviews-unsubscribe@spark.apache.org
For queries about this service, please contact Infrastructure at:
users@infra.apache.org
---------------------------------------------------------------------
To unsubscribe, e-mail: reviews-unsubscribe@spark.apache.org
For additional commands, e-mail: reviews-help@spark.apache.org
Re: [PR] [SPARK-46769][SQL] Refine timestamp related schema inference [spark]
Posted by "cloud-fan (via GitHub)" <gi...@apache.org>.
cloud-fan commented on PR #44800:
URL: https://github.com/apache/spark/pull/44800#issuecomment-1900225154
cc @gengliangwang @MaxGekk @Hisoka-X
--
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: reviews-unsubscribe@spark.apache.org
For queries about this service, please contact Infrastructure at:
users@infra.apache.org
---------------------------------------------------------------------
To unsubscribe, e-mail: reviews-unsubscribe@spark.apache.org
For additional commands, e-mail: reviews-help@spark.apache.org
Re: [PR] [SPARK-46769][SQL] Refine timestamp related schema inference [spark]
Posted by "cloud-fan (via GitHub)" <gi...@apache.org>.
cloud-fan commented on code in PR #44800:
URL: https://github.com/apache/spark/pull/44800#discussion_r1459234868
##########
sql/core/src/test/scala/org/apache/spark/sql/execution/datasources/csv/CSVSuite.scala:
##########
@@ -1105,10 +1105,12 @@ abstract class CSVSuite
test("SPARK-37326: Timestamp type inference for a column with TIMESTAMP_NTZ values") {
withTempPath { path =>
- val exp = spark.sql("""
- select timestamp_ntz'2020-12-12 12:12:12' as col0 union all
- select timestamp_ntz'2020-12-12 12:12:12' as col0
- """)
+ val exp = spark.sql(
+ """
+ |select *
+ |from values (timestamp_ntz'2020-12-12 12:12:12'), (timestamp_ntz'2020-12-12 12:12:12')
Review Comment:
If we change test like this (values in one partition), the test will fail in the latest master branch. It's because we use the ntz parser to infer LTZ only for the first value, which happened to work before because we use `union all` and the data has 2 partitions, each has only one value.
--
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: reviews-unsubscribe@spark.apache.org
For queries about this service, please contact Infrastructure at:
users@infra.apache.org
---------------------------------------------------------------------
To unsubscribe, e-mail: reviews-unsubscribe@spark.apache.org
For additional commands, e-mail: reviews-help@spark.apache.org
Re: [PR] [SPARK-46769][SQL] Refine timestamp related schema inference [spark]
Posted by "gengliangwang (via GitHub)" <gi...@apache.org>.
gengliangwang commented on code in PR #44800:
URL: https://github.com/apache/spark/pull/44800#discussion_r1460158163
##########
sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/json/JsonInferSchema.scala:
##########
@@ -159,16 +161,28 @@ class JsonInferSchema(options: JSONOptions) extends Serializable with Logging {
val bigDecimal = decimalParser(field)
DecimalType(bigDecimal.precision, bigDecimal.scale)
}
- val timestampType = SQLConf.get.timestampType
if (options.prefersDecimal && decimalTry.isDefined) {
decimalTry.get
- } else if (options.inferTimestamp && (SQLConf.get.legacyTimeParserPolicy ==
- LegacyBehaviorPolicy.LEGACY || timestampType == TimestampNTZType) &&
+ } else if (options.inferTimestamp) {
+ // For text-based format, it's ambiguous to infer a timestamp string without timezone, as
+ // it can be both TIMESTAMP LTZ and NTZ. To avoid behavior changes with the new support
+ // of NTZ, here we only try to infer NTZ if the config is set to use NTZ by default.
+ if (isDefaultNTZ &&
timestampNTZFormatter.parseWithoutTimeZoneOptional(field, false).isDefined) {
- timestampType
- } else if (options.inferTimestamp &&
- timestampFormatter.parseOptional(field).isDefined) {
- TimestampType
+ TimestampNTZType
+ } else if (timestampFormatter.parseOptional(field).isDefined) {
+ TimestampType
+ } else {
+ val utf8Value = UTF8String.fromString(field)
+ // There was a mistake that we use TIMESTAMP NTZ parser to infer LTZ type.
+ // The mistake makes it easier to infer TIMESTAMP LTZ type and we have to keep this
+ // behavior now. See SPARK-46769 for more details.
+ if (SparkDateTimeUtils.stringToTimestampWithoutTimeZone(utf8Value, false).isDefined) {
Review Comment:
Shall we combine the two conditions for TimestampType?
```
else if (timestampFormatter.parseOptional(field).isDefined || timestampNTZFormatter.parseOptional(field).isDefined)
```
Also, it is a bit weird to use SparkDateTimeUtils.stringToTimestampWithoutTimeZone here since the previous code was using the formatters.
--
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: reviews-unsubscribe@spark.apache.org
For queries about this service, please contact Infrastructure at:
users@infra.apache.org
---------------------------------------------------------------------
To unsubscribe, e-mail: reviews-unsubscribe@spark.apache.org
For additional commands, e-mail: reviews-help@spark.apache.org
Re: [PR] [SPARK-46769][SQL] Refine timestamp related schema inference [spark]
Posted by "cloud-fan (via GitHub)" <gi...@apache.org>.
cloud-fan commented on PR #44800:
URL: https://github.com/apache/spark/pull/44800#issuecomment-1902087546
thanks for the review, merging to master!
--
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: reviews-unsubscribe@spark.apache.org
For queries about this service, please contact Infrastructure at:
users@infra.apache.org
---------------------------------------------------------------------
To unsubscribe, e-mail: reviews-unsubscribe@spark.apache.org
For additional commands, e-mail: reviews-help@spark.apache.org
Re: [PR] [SPARK-46769][SQL] Refine timestamp related schema inference [spark]
Posted by "gengliangwang (via GitHub)" <gi...@apache.org>.
gengliangwang commented on PR #44800:
URL: https://github.com/apache/spark/pull/44800#issuecomment-1900912818
LGTM except for one comment
--
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: reviews-unsubscribe@spark.apache.org
For queries about this service, please contact Infrastructure at:
users@infra.apache.org
---------------------------------------------------------------------
To unsubscribe, e-mail: reviews-unsubscribe@spark.apache.org
For additional commands, e-mail: reviews-help@spark.apache.org
Re: [PR] [SPARK-46769][SQL] Refine timestamp related schema inference [spark]
Posted by "cloud-fan (via GitHub)" <gi...@apache.org>.
cloud-fan commented on code in PR #44800:
URL: https://github.com/apache/spark/pull/44800#discussion_r1460158951
##########
sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/json/JsonInferSchema.scala:
##########
@@ -159,16 +161,28 @@ class JsonInferSchema(options: JSONOptions) extends Serializable with Logging {
val bigDecimal = decimalParser(field)
DecimalType(bigDecimal.precision, bigDecimal.scale)
}
- val timestampType = SQLConf.get.timestampType
if (options.prefersDecimal && decimalTry.isDefined) {
decimalTry.get
- } else if (options.inferTimestamp && (SQLConf.get.legacyTimeParserPolicy ==
- LegacyBehaviorPolicy.LEGACY || timestampType == TimestampNTZType) &&
+ } else if (options.inferTimestamp) {
+ // For text-based format, it's ambiguous to infer a timestamp string without timezone, as
+ // it can be both TIMESTAMP LTZ and NTZ. To avoid behavior changes with the new support
+ // of NTZ, here we only try to infer NTZ if the config is set to use NTZ by default.
+ if (isDefaultNTZ &&
timestampNTZFormatter.parseWithoutTimeZoneOptional(field, false).isDefined) {
- timestampType
- } else if (options.inferTimestamp &&
- timestampFormatter.parseOptional(field).isDefined) {
- TimestampType
+ TimestampNTZType
+ } else if (timestampFormatter.parseOptional(field).isDefined) {
+ TimestampType
+ } else {
+ val utf8Value = UTF8String.fromString(field)
+ // There was a mistake that we use TIMESTAMP NTZ parser to infer LTZ type.
+ // The mistake makes it easier to infer TIMESTAMP LTZ type and we have to keep this
+ // behavior now. See SPARK-46769 for more details.
+ if (SparkDateTimeUtils.stringToTimestampWithoutTimeZone(utf8Value, false).isDefined) {
Review Comment:
It was a mistake previously, and I don't think we should keep doing it. e.g. the `timestampNTZFormatter` can have very different behavior with a user-specified pattern string. Then we infer LTZ and hit runtime error at read time because we can't really parse the value to LTZ.
--
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: reviews-unsubscribe@spark.apache.org
For queries about this service, please contact Infrastructure at:
users@infra.apache.org
---------------------------------------------------------------------
To unsubscribe, e-mail: reviews-unsubscribe@spark.apache.org
For additional commands, e-mail: reviews-help@spark.apache.org