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Posted to gitbox@hive.apache.org by "zhangbutao (via GitHub)" <gi...@apache.org> on 2024/06/05 15:56:15 UTC
[PR] HIVE-28306: Iceberg: Return new scan after applying column project parameter [hive]
zhangbutao opened a new pull request, #5282:
URL: https://github.com/apache/hive/pull/5282
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1. shoud return a new scan applying column project parameter, Otherwise it doesn't make any sense
2. `scan.project()` and `scan.select()` can not be specified at the same time
Check this:
https://github.com/apache/iceberg/pull/1353/files#diff-a94dee2a22a2890689a84529a978a769bdc3b084f35d79caf9608d49b2e1cc1b
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Existing tests.
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Re: [PR] HIVE-28306: Iceberg: Return new scan after applying column project parameter [hive]
Posted by "zhangbutao (via GitHub)" <gi...@apache.org>.
zhangbutao commented on code in PR #5282:
URL: https://github.com/apache/hive/pull/5282#discussion_r1628711004
##########
iceberg/iceberg-handler/src/main/java/org/apache/iceberg/mr/mapreduce/IcebergInternalRecordWrapper.java:
##########
@@ -57,7 +57,7 @@ public IcebergInternalRecordWrapper(StructType tableSchema, StructType readSchem
public IcebergInternalRecordWrapper wrap(StructLike record) {
int idx = 0;
for (Types.NestedField field : readSchema.fields()) {
- int position = fieldToPositionInTableSchema.get(field.name());
+ int position = fieldToPositionInReadSchema.get(field.name());
Review Comment:
Fixed the failed metadata qtest: http://ci.hive.apache.org/blue/organizations/jenkins/hive-precommit/detail/PR-5282/1/tests/
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Re: [PR] HIVE-28306: Iceberg: Return new scan after applying column project parameter [hive]
Posted by "zhangbutao (via GitHub)" <gi...@apache.org>.
zhangbutao commented on code in PR #5282:
URL: https://github.com/apache/hive/pull/5282#discussion_r1631894680
##########
iceberg/iceberg-handler/src/main/java/org/apache/iceberg/mr/mapreduce/IcebergInputFormat.java:
##########
@@ -175,14 +174,19 @@ CombinedScanTask> applyConfig(
Long openFileCost = splitSize > 0 ? splitSize : TableProperties.SPLIT_SIZE_DEFAULT;
scan = scan.option(TableProperties.SPLIT_OPEN_FILE_COST, String.valueOf(openFileCost));
}
- String schemaStr = conf.get(InputFormatConfig.READ_SCHEMA);
- if (schemaStr != null) {
- scan.project(SchemaParser.fromJson(schemaStr));
- }
-
- String[] selectedColumns = conf.getStrings(InputFormatConfig.SELECTED_COLUMNS);
- if (selectedColumns != null) {
- scan.select(selectedColumns);
+ // TODO: Currently, this projection optimization stored on scan is not being used effectively on Hive side, as
Review Comment:
@deniskuzZ Added TODO here, Please help to check if it is ok.
Thanks.
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Re: [PR] HIVE-28306: Iceberg: Return new scan after applying column project parameter [hive]
Posted by "deniskuzZ (via GitHub)" <gi...@apache.org>.
deniskuzZ commented on code in PR #5282:
URL: https://github.com/apache/hive/pull/5282#discussion_r1629729932
##########
iceberg/iceberg-handler/src/main/java/org/apache/iceberg/mr/mapreduce/IcebergInputFormat.java:
##########
@@ -177,12 +177,9 @@ CombinedScanTask> applyConfig(
}
String schemaStr = conf.get(InputFormatConfig.READ_SCHEMA);
if (schemaStr != null) {
- scan.project(SchemaParser.fromJson(schemaStr));
- }
-
- String[] selectedColumns = conf.getStrings(InputFormatConfig.SELECTED_COLUMNS);
- if (selectedColumns != null) {
- scan.select(selectedColumns);
+ scan = scan.project(SchemaParser.fromJson(schemaStr));
Review Comment:
why don't we use helper methods:
````
Schema readSchema = InputFormatConfig.readSchema(conf);
if (readSchema != null) {
scan = scan.project(readSchema)
} else {
String[] selectedColumns = InputFormatConfig.selectedColumns(conf);
if (selectedColumns != null) {
scan = scan.select(selectedColumns)
}
}
````
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Re: [PR] HIVE-28306: Iceberg: Return new scan after applying column project parameter [hive]
Posted by "sonarcloud[bot] (via GitHub)" <gi...@apache.org>.
sonarcloud[bot] commented on PR #5282:
URL: https://github.com/apache/hive/pull/5282#issuecomment-2154784698
## [](https://sonarcloud.io/dashboard?id=apache_hive&pullRequest=5282) **Quality Gate passed**
Issues
 [1 New issue](https://sonarcloud.io/project/issues?id=apache_hive&pullRequest=5282&resolved=false&sinceLeakPeriod=true)
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Re: [PR] HIVE-28306: Iceberg: Return new scan after applying column project parameter [hive]
Posted by "zhangbutao (via GitHub)" <gi...@apache.org>.
zhangbutao commented on PR #5282:
URL: https://github.com/apache/hive/pull/5282#issuecomment-2151498192
Submitted a same PR in Apache Iceberg: https://github.com/apache/iceberg/pull/10449
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Re: [PR] HIVE-28306: Iceberg: Return new scan after applying column project parameter [hive]
Posted by "sonarcloud[bot] (via GitHub)" <gi...@apache.org>.
sonarcloud[bot] commented on PR #5282:
URL: https://github.com/apache/hive/pull/5282#issuecomment-2155852505
## [](https://sonarcloud.io/dashboard?id=apache_hive&pullRequest=5282) **Quality Gate passed**
Issues
 [2 New issues](https://sonarcloud.io/project/issues?id=apache_hive&pullRequest=5282&resolved=false&sinceLeakPeriod=true)
 [0 Accepted issues](https://sonarcloud.io/project/issues?id=apache_hive&pullRequest=5282&resolutions=WONTFIX)
Measures
 [0 Security Hotspots](https://sonarcloud.io/project/security_hotspots?id=apache_hive&pullRequest=5282&resolved=false&sinceLeakPeriod=true)
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Re: [PR] HIVE-28306: Iceberg: Return new scan after applying column project parameter [hive]
Posted by "deniskuzZ (via GitHub)" <gi...@apache.org>.
deniskuzZ commented on PR #5282:
URL: https://github.com/apache/hive/pull/5282#issuecomment-2152839813
@zhangbutao, does this mean we always read the complete schema from iceberg and then applied project on Hive side?
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Re: [PR] HIVE-28306: Iceberg: Return new scan after applying column project parameter [hive]
Posted by "sonarcloud[bot] (via GitHub)" <gi...@apache.org>.
sonarcloud[bot] commented on PR #5282:
URL: https://github.com/apache/hive/pull/5282#issuecomment-2150537711
## [](https://sonarcloud.io/dashboard?id=apache_hive&pullRequest=5282) **Quality Gate passed**
Issues
 [0 New issues](https://sonarcloud.io/project/issues?id=apache_hive&pullRequest=5282&resolved=false&sinceLeakPeriod=true)
 [0 Accepted issues](https://sonarcloud.io/project/issues?id=apache_hive&pullRequest=5282&resolutions=WONTFIX)
Measures
 [0 Security Hotspots](https://sonarcloud.io/project/security_hotspots?id=apache_hive&pullRequest=5282&resolved=false&sinceLeakPeriod=true)
 No data about Coverage
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[See analysis details on SonarCloud](https://sonarcloud.io/dashboard?id=apache_hive&pullRequest=5282)
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Re: [PR] HIVE-28306: Iceberg: Return new scan after applying column project parameter [hive]
Posted by "sonarcloud[bot] (via GitHub)" <gi...@apache.org>.
sonarcloud[bot] commented on PR #5282:
URL: https://github.com/apache/hive/pull/5282#issuecomment-2151371282
## [](https://sonarcloud.io/dashboard?id=apache_hive&pullRequest=5282) **Quality Gate passed**
Issues
 [1 New issue](https://sonarcloud.io/project/issues?id=apache_hive&pullRequest=5282&resolved=false&sinceLeakPeriod=true)
 [0 Accepted issues](https://sonarcloud.io/project/issues?id=apache_hive&pullRequest=5282&resolutions=WONTFIX)
Measures
 [0 Security Hotspots](https://sonarcloud.io/project/security_hotspots?id=apache_hive&pullRequest=5282&resolved=false&sinceLeakPeriod=true)
 No data about Coverage
 No data about Duplication
[See analysis details on SonarCloud](https://sonarcloud.io/dashboard?id=apache_hive&pullRequest=5282)
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Re: [PR] HIVE-28306: Iceberg: Return new scan after applying column project parameter [hive]
Posted by "deniskuzZ (via GitHub)" <gi...@apache.org>.
deniskuzZ commented on code in PR #5282:
URL: https://github.com/apache/hive/pull/5282#discussion_r1629729932
##########
iceberg/iceberg-handler/src/main/java/org/apache/iceberg/mr/mapreduce/IcebergInputFormat.java:
##########
@@ -177,12 +177,9 @@ CombinedScanTask> applyConfig(
}
String schemaStr = conf.get(InputFormatConfig.READ_SCHEMA);
if (schemaStr != null) {
- scan.project(SchemaParser.fromJson(schemaStr));
- }
-
- String[] selectedColumns = conf.getStrings(InputFormatConfig.SELECTED_COLUMNS);
- if (selectedColumns != null) {
- scan.select(selectedColumns);
+ scan = scan.project(SchemaParser.fromJson(schemaStr));
Review Comment:
why don't we use helper methods:
````
Schema readSchema = InputFormatConfig.readSchema(conf);
if (readSchema != null) {
scan = scan.project(readSchema);
} else {
String[] selectedColumns = InputFormatConfig.selectedColumns(conf);
if (selectedColumns != null) {
scan = scan.select(selectedColumns)
}
}
````
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Re: [PR] HIVE-28306: Iceberg: Return new scan after applying column project parameter [hive]
Posted by "sonarcloud[bot] (via GitHub)" <gi...@apache.org>.
sonarcloud[bot] commented on PR #5282:
URL: https://github.com/apache/hive/pull/5282#issuecomment-2151582114
## [](https://sonarcloud.io/dashboard?id=apache_hive&pullRequest=5282) **Quality Gate passed**
Issues
 [1 New issue](https://sonarcloud.io/project/issues?id=apache_hive&pullRequest=5282&resolved=false&sinceLeakPeriod=true)
 [0 Accepted issues](https://sonarcloud.io/project/issues?id=apache_hive&pullRequest=5282&resolutions=WONTFIX)
Measures
 [0 Security Hotspots](https://sonarcloud.io/project/security_hotspots?id=apache_hive&pullRequest=5282&resolved=false&sinceLeakPeriod=true)
 No data about Coverage
 No data about Duplication
[See analysis details on SonarCloud](https://sonarcloud.io/dashboard?id=apache_hive&pullRequest=5282)
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Re: [PR] HIVE-28306: Iceberg: Return new scan after applying column project parameter [hive]
Posted by "zhangbutao (via GitHub)" <gi...@apache.org>.
zhangbutao commented on code in PR #5282:
URL: https://github.com/apache/hive/pull/5282#discussion_r1630744602
##########
iceberg/iceberg-handler/src/main/java/org/apache/iceberg/mr/mapreduce/IcebergInputFormat.java:
##########
@@ -177,12 +177,9 @@ CombinedScanTask> applyConfig(
}
String schemaStr = conf.get(InputFormatConfig.READ_SCHEMA);
if (schemaStr != null) {
- scan.project(SchemaParser.fromJson(schemaStr));
- }
-
- String[] selectedColumns = conf.getStrings(InputFormatConfig.SELECTED_COLUMNS);
- if (selectedColumns != null) {
- scan.select(selectedColumns);
+ scan = scan.project(SchemaParser.fromJson(schemaStr));
Review Comment:
> btw, there is `expectedSchema = readSchema(conf, table, caseSensitive)` but it creates a Hive schema with virtual columns, maybe that could be reused
I didn't find a better way to reuse this method. :(
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Re: [PR] HIVE-28306: Iceberg: Return new scan after applying column project parameter [hive]
Posted by "deniskuzZ (via GitHub)" <gi...@apache.org>.
deniskuzZ commented on PR #5282:
URL: https://github.com/apache/hive/pull/5282#issuecomment-2155498550
> > @zhangbutao, does this mean we always read the complete schema from iceberg and then applied project on Hive side? that should reduce number of bytes read, right?
>
> @deniskuzZ Not completely right. I think the original intention `project()` & `select()` stored on `scan `is to reduce the number of bytes read. But **on Hive side**, i found that we didn't take full advantage of the `column projection` propertity stored on `scan`. After some debugging, i think the main use `project()` & `select()` on scan is here,: just to do some scan metrics **but we don't use on Hive**: https://github.com/apache/iceberg/blob/c7de6cb345995cb47312edbef6edae2f17fb8aba/core/src/main/java/org/apache/iceberg/SnapshotScan.java#L143-L157
>
> In fact, on Hive side, we propagate the `projected column` through `conf` not the `scan` class, and we get this `projected column` through conf where we need it, some code snippet like this:
>
> https://github.com/apache/hive/blob/98d9d22398370f817fe64449368671b978fff096/iceberg/iceberg-handler/src/main/java/org/apache/iceberg/mr/mapreduce/IcebergInputFormat.java#L342
>
> the final place in hive which use `projected column` is here(Parquet iceberg table):
>
> https://github.com/apache/hive/blob/98d9d22398370f817fe64449368671b978fff096/iceberg/iceberg-handler/src/main/java/org/apache/iceberg/mr/mapreduce/IcebergInputFormat.java#L510
>
> In one word, with or without this my change, we both can optimize the `project column`, as on Hive we don't rely on the `project()` & `select()` stored on `scan`, and we just use conf to propagate the `projected column`. But we need make the code correct & return the new scan, so that we can do some stuff in the future by using the `project()` & `select()` stored on `scan`. `
since it's not used now, could we add TODO otherwise that would be just a dead code
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Re: [PR] HIVE-28306: Iceberg: Return new scan after applying column project parameter [hive]
Posted by "deniskuzZ (via GitHub)" <gi...@apache.org>.
deniskuzZ commented on code in PR #5282:
URL: https://github.com/apache/hive/pull/5282#discussion_r1629735031
##########
iceberg/iceberg-handler/src/main/java/org/apache/iceberg/mr/mapreduce/IcebergInputFormat.java:
##########
@@ -177,12 +177,9 @@ CombinedScanTask> applyConfig(
}
String schemaStr = conf.get(InputFormatConfig.READ_SCHEMA);
if (schemaStr != null) {
- scan.project(SchemaParser.fromJson(schemaStr));
- }
-
- String[] selectedColumns = conf.getStrings(InputFormatConfig.SELECTED_COLUMNS);
- if (selectedColumns != null) {
- scan.select(selectedColumns);
+ scan = scan.project(SchemaParser.fromJson(schemaStr));
Review Comment:
btw, there is `expectedSchema = readSchema(conf, table, caseSensitive)`
but it creates a Hive schema with virtual columns, maybe that could be reused
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Re: [PR] HIVE-28306: Iceberg: Return new scan after applying column project parameter [hive]
Posted by "zhangbutao (via GitHub)" <gi...@apache.org>.
zhangbutao commented on PR #5282:
URL: https://github.com/apache/hive/pull/5282#issuecomment-2154202895
> @zhangbutao, does this mean we always read the complete schema from iceberg and then applied project on Hive side? that should reduce number of bytes read, right?
@deniskuzZ Not completely right. I think the original intention `project()` & `select()` stored on `scan `is to reduce the number of bytes read.
But **on Hive side**, i found that we didn't take full advantage of the `column projection` propertity stored on `scan`. After some debugging, i think the main use `project()` & `select()` on scan is here,: just to do some scan metrics **but we don't use on Hive**:
https://github.com/apache/iceberg/blob/c7de6cb345995cb47312edbef6edae2f17fb8aba/core/src/main/java/org/apache/iceberg/SnapshotScan.java#L143-L157
In fact, on Hive side, we propagate the `projected column` through `conf` not the `scan` class, and we get this `projected column` through conf where we need it, some code snippet like this:
https://github.com/apache/hive/blob/98d9d22398370f817fe64449368671b978fff096/iceberg/iceberg-handler/src/main/java/org/apache/iceberg/mr/mapreduce/IcebergInputFormat.java#L342
the final place in hive which use `projected column` is here(Parquet iceberg table):
https://github.com/apache/hive/blob/98d9d22398370f817fe64449368671b978fff096/iceberg/iceberg-handler/src/main/java/org/apache/iceberg/mr/mapreduce/IcebergInputFormat.java#L510
In one word, with or without this my change, we both can optimize the `project column`, as on Hive we don't rely on the `project()` & `select()` stored on `scan`, and we just use conf to propagate the `projected column`.
But we need make the code correct & return the new scan, so that we can do some stuff in the future by using the `project()` & `select()` stored on `scan`.
`
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Re: [PR] HIVE-28306: Iceberg: Return new scan after applying column project parameter [hive]
Posted by "deniskuzZ (via GitHub)" <gi...@apache.org>.
deniskuzZ merged PR #5282:
URL: https://github.com/apache/hive/pull/5282
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Re: [PR] HIVE-28306: Iceberg: Return new scan after applying column project parameter [hive]
Posted by "sonarcloud[bot] (via GitHub)" <gi...@apache.org>.
sonarcloud[bot] commented on PR #5282:
URL: https://github.com/apache/hive/pull/5282#issuecomment-2155987415
## [](https://sonarcloud.io/dashboard?id=apache_hive&pullRequest=5282) **Quality Gate passed**
Issues
 [2 New issues](https://sonarcloud.io/project/issues?id=apache_hive&pullRequest=5282&resolved=false&sinceLeakPeriod=true)
 [0 Accepted issues](https://sonarcloud.io/project/issues?id=apache_hive&pullRequest=5282&resolutions=WONTFIX)
Measures
 [0 Security Hotspots](https://sonarcloud.io/project/security_hotspots?id=apache_hive&pullRequest=5282&resolved=false&sinceLeakPeriod=true)
 No data about Coverage
 No data about Duplication
[See analysis details on SonarCloud](https://sonarcloud.io/dashboard?id=apache_hive&pullRequest=5282)
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