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Does PostgreSQL have a limit on # of tables in a join?

开发者 https://www.devze.com 2023-02-22 22:08 出处:网络
Today when playing around with dynamic query generation I discovered that mysql has a hard maximum limit of how many tables can be used in a join: 61.

Today when playing around with dynamic query generation I discovered that mysql has a hard maximum limit of how many tables can be used in a join: 61.

This lead me 开发者_高级运维to wonder about PostgreSQL, does PostgreSQL have a analogous limit?

Note: I am asking this out of curiosity, not need.


There is no limit AFAIK.

The query optimizer will switch to a different algorithm once a (configurable) limit of tables has been exceeded.But that just means the plan is calculated in a different way, not that the statement will fail (it might not be the fastest plan though).

http://www.postgresql.org/docs/current/static/planner-optimizer.html

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