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A little signal. Less noise.

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A considered collection of AI tools, trials, and opportunities.

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A little signal. Less noise.

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RADARGood tools open new possibilities.Explore thoughtfully. Create freely.

Skip to content

A little signal. Less noise.

DISCOVER

Catalog Categories

CATEGORIES

Categories will appear when the source is connected.

More possibility. Less searching.

A considered collection of AI tools, trials, and opportunities.

RADAR / PostgreSQLStorage available

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A little signal. Less noise.

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索

索引建了却不走?7 个失效原因逐层排查

掘金

About this offer

EXPLAIN 里 key 是 NULL,多半不是索引没建好,而是写法逼优化器放弃了它:函数运算、隐式转换、最左前缀、前置百分号、OR 不对等、回表成本过高——逐个排查,优先改写 SQL。

Offer details

Provider: 掘金
Source: juejin-rss
Score: 57.38
Confidence: 54%

Source evidence

What RADAR observed and classified to build this opportunity. It is what the source published, not a verification that the offer is still active.

JuejinObserved: Oct 7, 2026Source reliability: 60%
索引建了却不走?7 个失效原因逐层排查. EXPLAIN 里 key 是 NULL,多半不是索引没建好,而是写法逼优化器放弃了它:函数运算、隐式转换、最左前缀、前置百分号、OR 不对等、回表成本过高——逐个排查,优先改写 SQL。
Open source

索引建了却不走?7 个失效原因逐层排查

Opens an external website. Availability and terms may change.

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The catalog shows persisted RADAR opportunities. Storage availability does not mean sources are verified or offers are active.

RADARGood tools open new possibilities.Explore thoughtfully. Create freely.