No need to read full RowGroup when using RowRanges
Nobody has claimed this yet.
Assessment
- Difficulty
- 4/5
- Estimated time
- 3-5 days
- Newbie friendliness
- 45/100
- Issue type
- Feature
- Clarity
- Mostly clear
- Activity status
- Quiet
- Tech stack
- java
- Domain
- data-engineering
Research direction
Start at ParquetFileReader.readFilteredRowGroup() and trace how RowRanges.createSingle(10) is handled when loading a row group. Determine where the full row group is read and how range filtering could limit network reads and memory use; done means the requested rows can be read without loading the full row group.
Written by the indexing model from the issue text.
Description
Describe the enhancement requested
I'm using ParquetFileReader and would like to read the few first line of a parquet file to show a preview to the user.
I'm doing this :
PageReadStore rowGroup = reader.readFilteredRowGroup(0, RowRanges.createSingle(10));
and then :
ColumnReadStore colReadStore = new ColumnReadStoreImpl(rowGroup,
new GroupRecordConverter(schema).getRootConverter(),
schemaLecture, ...);
etc.
The problem is when calling readFilteredRowGroup(), it reads the full row group in memory, which in my case is slow because the parquet file is on a network drive and has quite big row group. On top of that, it consumes RAM for nothing.
Is this an issue or could it be improved ?
Thanks in advance.
Olivier
Component(s)
No response
- Dominant language
- Java
- Stars
- 3.1k
- Forks
- 1.6k
- Avg merge
- 6d 16h
- Merged PRs (30d)
- 36
Contributor guide
No contributing guide indexed for this repository
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
More from apache/parquet-java
-
Type: bug
Difficulty 2/5 1-3 hours Newbie friendliness 68/100
apache/parquet-java#3792 ·
-
Difficulty 2/5 1-3 hours Newbie friendliness 82/100
apache/parquet-java#3767 ·
-
Difficulty 2/5 1-3 hours Newbie friendliness 72/100
apache/parquet-java#3695 · 1 comment ·
-
Difficulty 2/5 1-3 hours Newbie friendliness 78/100
apache/parquet-java#3667 ·
-
Type: bug
Difficulty 2/5 1-3 hours Newbie friendliness 76/100
apache/parquet-java#3587 ·
All issues in apache/parquet-java
Similar issues
-
documentation
Difficulty 2/5 1-3 hours Newbie friendliness 65/100
inu-appcenter/memorIN-backend#288 ·
-
Difficulty 2/5 1-3 hours Newbie friendliness 65/100
-
frontend maui-pilot pilot-ask question
Difficulty 2/5 1-3 hours Newbie friendliness 75/100
-
Difficulty 2/5 1-3 hours Newbie friendliness 75/100
-
area/plugin
Difficulty 2/5 1-3 hours Newbie friendliness 75/100
kestra-io/plugin-kestra#190 ·