SET SESSION transaction_prealloc_size=1024*1024*1024*1; SHOW PROCESSLIST; Id User Host db Command Time State Info <Id> root localhost test Query <Time> NULL SHOW PROCESSLIST SET SESSION transaction_prealloc_size=1024*1024*1024*2; SHOW PROCESSLIST; Id User Host db Command Time State Info <Id> root localhost test Query <Time> NULL SHOW PROCESSLIST SET SESSION transaction_prealloc_size=1024*1024*1024*3; SHOW PROCESSLIST; Id User Host db Command Time State Info <Id> root localhost test Query <Time> NULL SHOW PROCESSLIST SET SESSION transaction_prealloc_size=1024*1024*1024*4; SHOW PROCESSLIST; Id User Host db Command Time State Info <Id> root localhost test Query <Time> NULL SHOW PROCESSLIST SET SESSION transaction_prealloc_size=1024*1024*1024*5; SHOW PROCESSLIST; Id User Host db Command Time State Info <Id> root localhost test Query <Time> NULL SHOW PROCESSLIST