On 2020-10-14 01:30, Fujii Masao wrote:
On 2020/10/13 10:40, Kasahara Tatsuhito wrote:
On Fri, Oct 9, 2020 at 5:44 PM Shinya Okano
<btokan...@oss.nttdata.com> wrote:
Regarding the toast_tuple_target parameter of CREATE TABLE, the
documentation says that it only affects External or Extended, but it
actually affects the compression of Main as well.
The attached patch modifies the document to match the actual
behavior.
+1
+1
+ we try to compress long column values or to move into TOAST
tables, and
"we try to compress and/or move long column values into TOAST tables,
and" is better?
Thank you everyone for reviews.
I attached the new version of the patch.
Regards,
--
Shinya Okano
diff --git a/doc/src/sgml/ref/create_table.sgml b/doc/src/sgml/ref/create_table.sgml
index 28f844071b..fd6777ae01 100644
--- a/doc/src/sgml/ref/create_table.sgml
+++ b/doc/src/sgml/ref/create_table.sgml
@@ -1359,10 +1359,11 @@ WITH ( MODULUS <replaceable class="parameter">numeric_literal</replaceable>, REM
<listitem>
<para>
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.
