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From: "David G. Johnston" <david.g.johnston@gmail.com>
Date: Wed, 1 Oct 2025 07:20:34 -0500
Message-ID: 
 <CAKFQuwaHbepRV5PRb-J-uTgJRSWCsdPXM3SY5KivVPa+y2xM7w@mail.gmail.com>
Subject: 
 =?UTF-8?Q?Re=3A_in_the_different_schema_=EF=BC=8Cthe_sequence_name_is_?=
	=?UTF-8?Q?same=EF=BC=8C_and_a_table=27s_column_definition_use_this_sequence=2Cso?=
	=?UTF-8?Q?=EF=BC=8Chow_can_I_identify_sequence=27s_schema_name_by_system_view=2F?=
	=?UTF-8?Q?table=3A?=
To: yanliang lei <msdnchina@163.com>
Cc: "pgsql-docs@lists.postgresql.org" <pgsql-docs@lists.postgresql.org>
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On Wednesday, October 1, 2025, yanliang lei <msdnchina@163.com> wrote:
>
> dbversion180=3D# create table schema_1.test_tab_100(c1 int default
> nextval('seq_xx_yy'));
>

Since you didn=E2=80=99t schema qualify the sequence name every single time=
 a
default value is created the sequence will be looked up anew.  The stored
expression is not associated with any specific object.

This is also why there is a separate step to mark a sequence as being owned
by a table.  That establishes a dependency that this textual form is unable
to do.

David J.

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On Wednesday, October 1, 2025, yanliang lei &lt;<a href=3D"mailto:msdnchina=
@163.com">msdnchina@163.com</a>&gt; wrote:<blockquote class=3D"gmail_quote"=
 style=3D"margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><d=
iv style=3D"line-height:1.7;color:#000000;font-size:14px;font-family:Arial"=
><div>dbversion180=3D# create table schema_1.test_tab_100(c1 int default  n=
extval(&#39;seq_xx_yy&#39;));
</div></div></blockquote><div><br></div><div>Since you didn=E2=80=99t schem=
a qualify the sequence name every single time a default value is created th=
e sequence will be looked up anew.=C2=A0 The stored expression is not assoc=
iated with any specific object.</div><div><br></div><div>This is also why t=
here is a separate step to mark a sequence as being owned by a table.=C2=A0=
 That establishes a dependency that this textual form is unable to do.</div=
><div><br></div><div>David J.</div><div><br></div><blockquote class=3D"gmai=
l_quote" style=3D"margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left=
:1ex"><div style=3D"line-height:1.7;color:#000000;font-size:14px;font-famil=
y:Arial"><div>
</div><div>
</div><div>
</div><div>
</div></div></blockquote>

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