PostgreSQL
8.20. pg_lsn Type
The pg_lsn data type can be used to store LSN (Log Sequence Number) data which is a pointer to a location in the WAL. This type is a representation of XLogRecPtr and an internal system type of PostgreSQL.
Internally, an LSN is a 64-bit integer, representing a byte position in the write-ahead log stream. It is printed as two hexadecimal numbers of up to 8 digits each, separated by a slash; for example, 16/B374D848. The pg_lsn type supports the standard comparison operators, like = and >. Two LSNs can be subtracted using the - operator; the result is the number of bytes separating those write-ahead log locations.
| Prev | Up | Next |
|---|---|---|
8.19. Object Identifier Types |
8.21. Pseudo-Types |
Submit correction
If you see anything in the documentation that is not correct, does not match your experience with the particular feature or requires further clarification, please use this form to report a documentation issue.
Copyright © 1996-2023 The PostgreSQL Global Development Group