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This topic has been translated from a Chinese forum by GPT and might contain errors.Original topic: sort_buffer_size参数是否有效
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username: 等一分钟
Is the sort_buffer_size parameter still useful?
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username: 等一分钟
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username: This is a MySQL parameter, I didn’t see this in the default TiDB configuration 
This way you can find it, but there is no relevant explanation on the official website.
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username: If it’s not on the official website, it means it has no effect. Ignore it.
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username: Hash Join
Merge Join
Index Join
Hash Join consumes a lot of resources but can be fast in parallel execution. It is optimal if you do not consider order by limit. Index Join is suitable for small quantities.
Use EXPLAIN to view the execution plan of JOIN queries | PingCAP Documentation Center
Let me ask another question.
Fast analyze hasn’t reached General Availability and only supports analyze version 1 currently.
The cluster was able to analyze tables before, and the configuration hasn’t been changed. Why can’t it update the statistics now?
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username: 
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username: Check what the value of the parameter tidb_analyze_version is.
If it is 2, execute set global tidb_analyze_version=1; then log in again and try analyze table?
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username: It wasn’t mentioned, which means it can’t be used and has no effect.