| --- |
| title: CHECKPOINT |
| --- |
| |
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| |
| Forces a transaction log checkpoint. |
| |
| ## <a id="topic1__section2"></a>Synopsis |
| |
| ``` pre |
| CHECKPOINT |
| ``` |
| |
| ## <a id="topic1__section3"></a>Description |
| |
| Write-Ahead Logging (WAL) puts a checkpoint in the transaction log every so often. The automatic checkpoint interval is set per HAWQ segment instance by the server configuration parameters `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. |
| |
| Only superusers may call `CHECKPOINT`. The command is not intended for use during normal operation. |
| |
| ## <a id="topic1__section4"></a>Compatibility |
| |
| The `CHECKPOINT` command is a HAWQ language extension. |
