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| author | Robert Haas <rhaas@postgresql.org> | 2011-06-21 22:15:24 -0400 |
|---|---|---|
| committer | Robert Haas <rhaas@postgresql.org> | 2011-06-21 22:21:24 -0400 |
| commit | 8f9fe6edce358f7904e0db119416b4d1080a83aa (patch) | |
| tree | a0a828d221e85af6c6bf5bc74a6c6c7190352cbf /doc/src | |
| parent | 771a9f69f70e0b4fa95347df7ab346e5bdbc85f2 (diff) | |
| download | postgresql-8f9fe6edce358f7904e0db119416b4d1080a83aa.tar.gz postgresql-8f9fe6edce358f7904e0db119416b4d1080a83aa.zip | |
Add notion of a "transform function" that can simplify function calls.
Initially, we use this only to eliminate calls to the varchar()
function in cases where the length is not being reduced and, therefore,
the function call is equivalent to a RelabelType operation. The most
significant effect of this is that we can avoid a table rewrite when
changing a varchar(X) column to a varchar(Y) column, where Y > X.
Noah Misch, reviewed by me and Alexey Klyukin
Diffstat (limited to 'doc/src')
| -rw-r--r-- | doc/src/sgml/catalogs.sgml | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/doc/src/sgml/catalogs.sgml b/doc/src/sgml/catalogs.sgml index 24d7d98722a..7a380ce2f94 100644 --- a/doc/src/sgml/catalogs.sgml +++ b/doc/src/sgml/catalogs.sgml @@ -4338,6 +4338,13 @@ </row> <row> + <entry><structfield>protransform</structfield></entry> + <entry><type>regproc</type></entry> + <entry><literal><link linkend="catalog-pg-proc"><structname>pg_proc</structname></link>.oid</literal></entry> + <entry>Calls to function can be simplified by this other function</entry> + </row> + + <row> <entry><structfield>proisagg</structfield></entry> <entry><type>bool</type></entry> <entry></entry> |