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Fix procedure for updating nextval() defaults so that it actually works.

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Update release dates for pending back-branch releases.
This commit is contained in:
Tom Lane
2005-10-03 16:04:13 +00:00
parent 8c73dfcc8b
commit 9c873828bd
1 changed files with 28 additions and 27 deletions
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55
doc/src/sgml/release.sgml
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@ -1,5 +1,5 @@
<!--
$PostgreSQL: pgsql/doc/src/sgml/release.sgml,v 1.386 2005/10/03 13:52:28 momjian Exp $
$PostgreSQL: pgsql/doc/src/sgml/release.sgml,v 1.387 2005/10/03 16:04:13 tgl Exp $
Typical markup:
@ -393,61 +393,62 @@ pg_[A-Za-z0-9_] <application>
<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 as simple 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 to handle sequence
arguments as internal OIDs, allowing them to track 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 old text-based behavior 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
explicitly casting the argument to <type>text</>, for example
<literal>nextval('myseq'::text)</>.
</para>
<para>
Pre-8.1 schemas loaded into 8.1 will use the previous, text-based
Pre-8.1 database dumps loaded into 8.1 will use the old text-based
representation and therefore will not have the features of
OID-stored arguments. However, it is possible to upgrade a
database loaded with pre-8.1 schemas. First, save this query into
a file, such as <filename>fixseq.sql</>:
OID-stored arguments. However, it is possible to update a
database containing text-based <literal>DEFAULT</> clauses.
First, save this query into a 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 process should be done for each database loaded with pre-8.1
schemas.
This process must be repeated in each database to be updated.
</para>
</listitem>
<listitem>
@ -2060,7 +2061,7 @@ psql -aT -f fixseq.sql db1 | psql -e db1
<note>
<title>Release date</title>
<simpara>2005-09-??</simpara>
<simpara>2005-10-04</simpara>
</note>
<para>
@ -4836,7 +4837,7 @@ typedefs (Michael)</para></listitem>
<note>
<title>Release date</title>
<simpara>2005-09-??</simpara>
<simpara>2005-10-04</simpara>
</note>
<para>
@ -7463,7 +7464,7 @@ DROP SCHEMA information_schema CASCADE;
<note>
<title>Release date</title>
<simpara>2005-09-??</simpara>
<simpara>2005-10-04</simpara>
</note>
<para>