預寫式日誌（Write-Ahead Logging (WAL)）預設時在事務日誌中每隔一段時間放一個檢查點。 （要調整這個原子化的檢查點間隔，你可以參考運行時選項 checkpoint_segments 和 checkpoint_segments 。） CHECKPOINT 強迫在命令聲明時立即進行檢查， 而不是等到下一次調度時的檢查點。
CHECKPOINT - 強制一個事務日誌檢查點
CHECKPOINT
預寫式日誌（Write-Ahead Logging (WAL)）預設時在事務日誌中每隔一段時間放一個檢查點。 （要調整這個原子化的檢查點間隔，你可以參考運行時選項 checkpoint_segments 和 checkpoint_segments 。） CHECKPOINT 強迫在命令聲明時立即進行檢查， 而不是等到下一次調度時的檢查點。
檢查點是一個事務日誌訓練中的點，在該點，所有數據文件都被更新以反映日誌中的信息。 所有數據文件都將被衝刷到磁碟。請參考 Chapter 25 ``Write-Ahead Logging'' 獲取更多有關 WAL 系統的信息。
只有超級用戶可以調用 CHECKPOINT。 該命令不是設計用於正常操作過程中的。
CHECKPOINT 命令是 PostgreSQL 語言的擴展。
CHECKPOINT - force a transaction log checkpoint
CHECKPOINT
Write-Ahead Logging (WAL) puts a checkpoint in the transaction log every so often. (To adjust the automatic checkpoint interval, see the run-time configuration options checkpoint_segments and checkpoint_timeout.) The CHECKPOINT command forces an immediate checkpoint when the command is issued, without waiting for a scheduled checkpoint.
A checkpoint is a point in the transaction log sequence at which all data files have been updated to reflect the information in the log. All data files will be flushed to disk. Refer to the the chapter called ``Write-Ahead Logging'' in the documentation for more information about the WAL system.
Only superusers may call CHECKPOINT. The command is not intended for use during normal operation.
The CHECKPOINT command is a PostgreSQL language extension.
【責任編輯：
韓亞珊TEL：（010）68476606】