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The toast_tuple_target specifies the minimum tuple length required before
- we try to move long column values into TOAST tables, and is also the
- target length we try to reduce the length below once toasting begins.
- This only affects columns marked as either External or Extended
- and applies only to new tuples; there is no effect on existing rows.
+ we try to compress and/or move long column values into TOAST tables, and
+ is also the target length we try to reduce the length below once toasting
+ begins. This affects columns marked as External (for move),
+ Main (for compression), or Extended (for both) and applies only to new
+ tuples. There is no effect on existing rows.
By default this parameter is set to allow at least 4 tuples per block,
which with the default block size will be 2040 bytes. Valid values are
between 128 bytes and the (block size - header), by default 8160 bytes.