where is transaction pool located in mysql ? (no replies)

Hi,

Where is transaction pool located in mysql ?

MySQL 5.7 introduced for Taransaction pool.
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Fixed chunks of 4MB each
Ordered on address, improves locality of reference
Improves performance of read-write transaction list scans
Reduces malloc()/free() overhead
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I wonder where transaction pool is located in mysql 5.7?
In InnoDB Buffer Pool? or System tablespace? or ?

Thanks.