Under the full or bulk-logged recovery models, until the first full backup, automatic checkpoints truncate the unused part of the transaction log, unless other factors are keeping log records active.

• 在完整或大容量日志恢复模式下,如果没有其他因素使日志记录保持为活动状态,则到进行第一次完整备份时,自动检查点才会截断事务日志的未使用部分。