diff options
| author | Neil Conway <neilc@samurai.com> | 2007-01-16 21:41:14 +0000 |
|---|---|---|
| committer | Neil Conway <neilc@samurai.com> | 2007-01-16 21:41:14 +0000 |
| commit | cf57ef4e506cd87195baa76213326b1981644452 (patch) | |
| tree | d46388824c263a2c2737a2ac5283706f065f634c /doc/src | |
| parent | da07c81fe3672fdc216b923f7abcde5d23ad0a6a (diff) | |
Implement width_bucket() for the float8 data type.
The implementation is somewhat ugly logic-wise, but I don't see an
easy way to make it more concise.
When writing this, I noticed that my previous implementation of
width_bucket() doesn't handle NaN correctly:
postgres=# select width_bucket('NaN', 1, 5, 5);
width_bucket
--------------
6
(1 row)
AFAICS SQL:2003 does not define a NaN value, so it doesn't address how
width_bucket() should behave here. The patch changes width_bucket() so
that ereport(ERROR) is raised if NaN is specified for the operand or the
lower or upper bounds to width_bucket(). For float8, NaN is disallowed
for any of the floating-point inputs, and +/- infinity is disallowed
for the histogram bounds (but allowed for the operand).
Update docs and regression tests, bump the catversion.
Diffstat (limited to 'doc/src')
| -rw-r--r-- | doc/src/sgml/func.sgml | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index b9cd00320b4..ea644106733 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/func.sgml,v 1.350 2007/01/12 23:34:54 tgl Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/func.sgml,v 1.351 2007/01/16 21:41:12 neilc Exp $ --> <chapter id="functions"> <title>Functions and Operators</title> @@ -854,6 +854,16 @@ <entry><literal>width_bucket(5.35, 0.024, 10.06, 5)</literal></entry> <entry><literal>3</literal></entry> </row> + + <row> + <entry><literal><function>width_bucket</function>(<parameter>op</parameter> <type>dp</type>, <parameter>b1</parameter> <type>dp</type>, <parameter>b2</parameter> <type>dp</type>, <parameter>count</parameter> <type>int</type>)</literal></entry> + <entry><type>int</type></entry> + <entry>return the bucket to which <parameter>operand</> would + be assigned in an equidepth histogram with <parameter>count</> + buckets, in the range <parameter>b1</> to <parameter>b2</></entry> + <entry><literal>width_bucket(5.35, 0.024, 10.06, 5)</literal></entry> + <entry><literal>3</literal></entry> + </row> </tbody> </tgroup> </table> |