pg_lo_lseek64

pg_lo_lseek64
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pg_lo_lseek64 — Seek to a position of a large object, using a 64-bit offset

Synopsis

pg_lo_lseek64 conn descriptor offset whence

Description

pg_lo_lseek64 moves the current read/write position to offset bytes from the position specified by whence. The offset is a 64-bit integer, allowing for larger size objects compare to pg_lo_lseek.

Arguments

conn: The handle of the connection.
descriptor: A descriptor for the large object from pg_lo_open.
offset: The new seek position in bytes, as a 64-bit integer.
whence: Specified from where to calculate the new seek position: SEEK_CUR (from current position), SEEK_END (from end), or SEEK_SET (from start).

Return Value

The current zero-based byte offset in the large object, after the seek is complete. This is identical to the value which would be returned by pg_lo_tell64, and is a 64-bit integer.

A Tcl error will be thrown if an error occurs.

Notes

All large object manipulation must take place within an SQL transaction block.

This command was added in pgtclng-2.1.0 and in pgintcl-3.5.0.

This command uses or emulates the PostgreSQL libpq function lo_lseek64. In order for pg_lo_lseek64 to be available and usable, the library must be be built and linked with PostgreSQL libpq 9.3.0 or higher (does not apply to pgintcl), and be connected to a PostgreSQL server version 9.3.0 or higher.

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