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$PostgreSQL: pgsql/doc/src/sgml/release.sgml,v 1.386 2005/10/0313:52:28 momjian Exp $

$PostgreSQL: pgsql/doc/src/sgml/release.sgml,v 1.387 2005/10/0316:04:13 tgl Exp $

Typical markup:

<listitem>

<para>

Add proper sequence function dependencies for <command>

DEFAULT</> clauses (Tom)

Add proper dependencies for arguments of sequence functions (Tom)

</para>

<para>

In previous releases, <function>nextval()</>,

<function>currval</>, and <function>setval()</>recorded sequence

names assimple text strings, meaning that renaming or dropping a

sequence used in a <command>DEFAULT</> clause made the clause

In previous releases,sequence names passed to<function>nextval()</>,

<function>currval()</>, and <function>setval()</>were stored as

simple text strings, meaning that renaming or dropping a

sequence used in a <literal>DEFAULT</> clause made the clause

invalid. This release stores all newly-created sequence function

arguments as internal OIDs, allowing them tohandle sequence

arguments as internal OIDs, allowing them totrack sequence

renaming, and adding dependency information that prevents

improper sequence removal. It also makes <command>DEFAULT</>

clauses immune to schema search path changes, and allows schema

renaming.

improper sequence removal. It also makes such <literal>DEFAULT</>

clauses immune to schema renaming and search path changes.

</para>

<para>

Some applications might rely on the oldtext-basedbehavior of

Some applications might rely on the old behavior of

run-time lookup for sequence names. This can still be done by

casting the argument to <type>text</>, for example

explicitlycasting the argument to <type>text</>, for example

<literal>nextval('myseq'::text)</>.

</para>

<para>

Pre-8.1schemasloaded into 8.1 will use theprevious, text-based

Pre-8.1database dumpsloaded into 8.1 will use theold text-based

representation and therefore will not have the features of

OID-stored arguments. However, it is possible toupgrade a

databaseloaded with pre-8.1 schemas. First, save this query into

a file, such as <filename>fixseq.sql</>:

OID-stored arguments. However, it is possible toupdate a

databasecontaining text-based <literal>DEFAULT</> clauses.

First, save this query intoa file, such as <filename>fixseq.sql</>:

<programlisting>

SELECT 'ALTER TABLE ' ||

pg_catalog.quote_ident(n.nspname) || '.' ||

pg_catalog.quote_ident(c.relname) ||

' ALTER COLUMN ' || pg_catalog.quote_ident(a.attname) ||

' SET DEFAULT ' ||

regexp_replace(d.adsrc, '(nextval\\(''[^'']*'')::text', '\\1', 'g') ||

regexp_replace(d.adsrc,

$$val\(\(('[^']*')::text\)::regclass$$,

$$val\(\1$$,

'g') ||

';'

FROM pg_namespace n, pg_class c, pg_attribute a, pg_attrdef d

WHERE n.oid = c.relnamespace AND

c.oid = a.attrelid AND

a.attrelid = d.adrelid AND

a.attnum = d.adnum AND

d.adsrc ~'.*nextval\\(''[^'']*''::text';

d.adsrc ~$$val\(\('[^']*'::text\)::regclass$$;

</programlisting>

Next, run the query against a database to find what

adjustments are required, like this for database <literal>db1</>:

<programlisting>

psql -aT -f fixseq.sql db1

psql -t -f fixseq.sql db1

</programlisting>

This will show the <command>ALTER TABLE</> commands needed to

convert the database to the newer OID-based representation.

Finally, run this to update the database:

If the commands look reasonable, run this to update the database:

<programlisting>

psql -aT -f fixseq.sql db1 | psql -e db1

psql -t -f fixseq.sql db1 | psql -e db1

</programlisting>

This processshould bedone for each databaseloaded with pre-8.1

This processmust berepeated in each databaseto be updated.

</listitem>

<listitem>

<note>

<title>Release date</title>

<simpara>2005-09-??</simpara>

<simpara>2005-10-04</simpara>

</note>

<para>

<note>

<title>Release date</title>

<simpara>2005-09-??</simpara>

<simpara>2005-10-04</simpara>

</note>

<para>

<note>

<title>Release date</title>

<simpara>2005-09-??</simpara>

<simpara>2005-10-04</simpara>

</note>

<para>