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$PostgreSQL: pgsql/doc/src/sgml/release.sgml,v 1.383 2005/10/03 02:21:16 momjian Exp $

$PostgreSQL: pgsql/doc/src/sgml/release.sgml,v 1.384 2005/10/03 02:46:43 momjian Exp $

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</para>

<para>

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

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

sequencenames as simple text strings, meaning that renaming or

dropping asequence used in a <command>DEFAULT</> made the

clauseinvalid. This release stores all newly-created sequence

functionargumentsusing internal OIDs, allowing them to handle

sequencerenaming, and adding dependency information that

preventsimproper sequence removal. It also makes

<command>DEFAULT</>clauses immune to schema search

path changes.

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

names as simple text strings, meaning that renaming or dropping a

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

invalid. This release stores all newly-created sequence function

argumentsas internal OIDs, allowing them to handle 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.

</para>

<para>

Some applications might rely on the old text-based behavior of

run-time lookupof thesequencename. This can still be done by

run-time lookupforsequencenames. This can still be done by

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

representation and therefore will not havethese protections.

However, it is possible to upgrade a database to the newer

OID-based arguments. First, save this query into a file, such as

<filename>fixseq.sql</>:

representation and therefore will not havethe 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</>:

<programlisting>

SELECT 'ALTER TABLE ' ||

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