kumar vishal created CARBONDATA-458:
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Summary: Improving carbon first time query performance
Key: CARBONDATA-458
URL: https://issues.apache.org/jira/browse/CARBONDATA-458
Project: CarbonData
Issue Type: Improvement
Components: core, data-load, data-query
Reporter: kumar vishal
Assignee: kumar vishal
Improving carbon first time query performance
Reason:
1. As file system cache is cleared file reading will make it slower to read and
cache
2. In first time query carbon will have to read the footer from file data file
to form the btree
3. Carbon reading more footer data than its required(data chunk)
4. There are lots of random seek is happening in carbon as column data(data
page, rle, inverted index) are not stored together.
Solution:
1. Improve block loading time. This can be done by removing data chunk from
blockletInfo and storing only offset and length of data chunk
2. compress presence meta bitset stored for null values for measure column
using snappy
3. Store the metadata and data of a column together and read together this
reduces random seek and improve IO
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