OpenTenBase / OpenTenBase/TXSQL

扩展hint配置index dive

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good first issue
Dominant language
C++
Stars
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Forks
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Description

扩展hint配置index dive
对索引列进行范围查询、且谓词等值条件数量小于eq_range_index_dive_limit时,优化器会使用索引下探(index dive)估计索引列上符合谓词条件的记录数。但是eq_range_index_dive_limit不能按SQL灵活配置。因此通过hint扩展。
示例:# 对 t1 的索引下探页面数量设置为 10, t2 的索引下探页面数量设置为 100.
select /+index_dive_pages(t1 10) index_dive_pages(t2 100)/ * from t1, t2 where t1.a = t2.a and t2.b > 20 and t1.b > 100;

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  3. Fork the repository and make your change on a branch.
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Research direction

Start by tracing the existing eq_range_index_dive_limit setting and the optimizer's index-dive path, then inspect how optimizer hints are parsed and applied. The issue names no files or tests; done should include an index_dive_pages hint that accepts the shown per-table values and affects index-dive estimation.

Written by the indexing model from the issue text.

Assessment

Tech stack
cpp
Domain
databases, performance
Issue type
Feature
Difficulty
5/5
Estimated time
Over a week
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
35/100

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