diff options
Diffstat (limited to 'doc/src')
| -rw-r--r-- | doc/src/sgml/datatype.sgml | 19 |
1 files changed, 16 insertions, 3 deletions
diff --git a/doc/src/sgml/datatype.sgml b/doc/src/sgml/datatype.sgml index 6646820d6a0..e0d33f12e1c 100644 --- a/doc/src/sgml/datatype.sgml +++ b/doc/src/sgml/datatype.sgml @@ -3369,7 +3369,7 @@ SELECT person.name, holidays.num_weeks FROM person, holidays </row> <row> <entry><type>line</type></entry> - <entry>32 bytes</entry> + <entry>24 bytes</entry> <entry>Infinite line</entry> <entry>{A,B,C}</entry> </row> @@ -3414,6 +3414,11 @@ SELECT person.name, holidays.num_weeks FROM person, holidays </table> <para> + In all these types, the individual coordinates are stored as + <type>double precision</type> (<type>float8</type>) numbers. + </para> + + <para> A rich set of functions and operators is available to perform various geometric operations such as scaling, translation, rotation, and determining intersections. They are explained in <xref linkend="functions-geometry"/>. @@ -3603,8 +3608,16 @@ SELECT person.name, holidays.num_weeks FROM person, holidays <para> Polygons are represented by lists of points (the vertices of the polygon). Polygons are very similar to closed paths; the essential - difference is that a polygon is considered to include the area - within it, while a path is not. + semantic difference is that a polygon is considered to include the + area within it, while a path is not. + </para> + + <para> + An important implementation difference between polygons and + paths is that the stored representation of a polygon includes its + smallest bounding box. This speeds up certain search operations, + although computing the bounding box adds overhead while constructing + new polygons. </para> <para> |