diff options
| author | Tom Lane | 2006-09-29 21:22:21 +0000 |
|---|---|---|
| committer | Tom Lane | 2006-09-29 21:22:21 +0000 |
| commit | 352a56ba68d00a4bce9944e1b0e6aeda8d3c021f (patch) | |
| tree | 8d3801c892b019547435dcd21fbad3e3e2322561 /doc/src | |
| parent | 673a573dcc1ef928a1047e75aba2926c692e76cc (diff) | |
Allow assignment to array elements not contiguous with those already
present; intervening positions are filled with nulls. This behavior
is required by SQL99 but was not implementable before 8.2 due to lack
of support for nulls in arrays. I have only made it work for the
one-dimensional case, which is all that SQL99 requires. It seems quite
complex to get it right in higher dimensions, and since we never allowed
extension at all in higher dimensions, I think that must count as a
future feature addition not a bug fix.
Diffstat (limited to 'doc/src')
| -rw-r--r-- | doc/src/sgml/array.sgml | 13 |
1 files changed, 7 insertions, 6 deletions
diff --git a/doc/src/sgml/array.sgml b/doc/src/sgml/array.sgml index 55e4085d0dd..3ed8ce9c043 100644 --- a/doc/src/sgml/array.sgml +++ b/doc/src/sgml/array.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/array.sgml,v 1.51 2006/05/09 23:12:54 momjian Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/array.sgml,v 1.52 2006/09/29 21:22:21 tgl Exp $ --> <sect1 id="arrays"> <title>Arrays</title> @@ -350,11 +350,12 @@ UPDATE sal_emp SET pay_by_quarter[1:2] = '{27000,27000}' </para> <para> - A stored array value can be enlarged by assigning to an element adjacent to - those already present, or by assigning to a slice that is adjacent - to or overlaps the data already present. For example, if array - <literal>myarray</> currently has 4 elements, it will have five - elements after an update that assigns to <literal>myarray[5]</>. + A stored array value can be enlarged by assigning to element(s) not already + present. Any positions between those previously present and the newly + assigned element(s) will be filled with nulls. For example, if array + <literal>myarray</> currently has 4 elements, it will have six + elements after an update that assigns to <literal>myarray[6]</>, + and <literal>myarray[5]</> will contain a null. Currently, enlargement in this fashion is only allowed for one-dimensional arrays, not multidimensional arrays. </para> |