| Type: | integer |
| Default: | -1 (-1) |
| Min: | -1 (-1) |
| Max: | 2147483647 (2147483647kB) |
| Unit: | KB |
| Context: | superuser |
| Restart: | false |
Controls logging of temporary file names and sizes. Temporary files can be created for sorts, hashes, and temporary query results. If enabled by this setting, a log entry is emitted for each temporary file, with the file size specified in bytes, when it is deleted. A value of zero logs all temporary file information, while positive values log only files whose size is greater than or equal to the specified amount of data. If this value is specified without units, it is taken as kilobytes. The default setting is -1, which disables such logging. Only superusers and users with the appropriate SET privilege can change this setting.
Recommendations
This logger is used for troubleshooting sorts and other activities which are spilling to disk. If you use it at all, it's probably good to set it a something low like 1kB so that you know each query that spilled to disk, since any disk spill at all causes a dramatic slowdown in the query. Can be used to see if you need more work_mem, temp_mem or maintenance_work_mem.