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Character will use more disk space than varchar so it does make a
difference.
=20
http://www.postgresql.org/docs/8.3/interactive/datatype-character.html
=20
Values of type character are physically padded with spaces to the
specified width n, and are stored and displayed that way. However, the
padding spaces are treated as semantically insignificant. Trailing
spaces are disregarded when comparing two values of type character, and
they will be removed when converting a character value to one of the
other string types. Note that trailing spaces are semantically
significant in character varying and text values.
=20
=20
=20
=20
Jon
=20
________________________________
From: pgsql-general-owner@[EMAIL PROTECTED]
On Behalf Of Mike Gould
Sent: Monday, June 23, 2008 1:01 PM
To: pgsql-general General
Subject: [GENERAL] Data Types
=20
We are converting our system from using Sybase's SQL Anywhere 10 to
PostGres 8.3. In SQL Anywhere there technically isn't any difference in
how a char and varchar is stored. They are all an array of char[1]. So
we always just defined everything as a char since right truncation is
the default.
In PostGres though if we are using a character type column to search
should we define that as a varchar or a char or does it make any
difference?
Best Regards
Michael Gould
Intermodal Software Solutions, LLC.
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<p class=3DMsoNormal><font size=3D2 color=3Dnavy face=3DArial><span =
style=3D'font-size:
10.0pt;font-family:Arial;color:navy'>Character will use more disk space =
than varchar
so it does make a difference.<o:p></o:p></span></font></p>
<p class=3DMsoNormal><font size=3D2 color=3Dnavy face=3DArial><span =
style=3D'font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
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style=3D'font-size:
10.0pt;font-family:Arial;color:navy'><a
href=3D"http://www.postgresql.org/docs/8.3/interactive/datatype-character=
..html">http://www.postgresql.org/docs/8.3/interactive/datatype-character.=
html</a><o:p></o:p></span></font></p>
<p class=3DMsoNormal><font size=3D2 color=3Dnavy face=3DArial><span =
style=3D'font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=3DMsoNormal><font size=3D2 color=3Dnavy face=3DArial><span =
style=3D'font-size:
10.0pt;font-family:Arial;color:navy'>Values of type character are =
physically
padded with spaces to the specified width n, and are stored and =
displayed that
way. However, the padding spaces are treated as semantically =
insignificant.
Trailing spaces are disregarded when comparing two values of type =
character,
and they will be removed when converting a character value to one of the =
other
string types. Note that trailing spaces are semantically significant in
character varying and text values.<o:p></o:p></span></font></p>
<p class=3DMsoNormal><font size=3D2 color=3Dnavy face=3DArial><span =
style=3D'font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
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<p class=3DMsoNormal><font size=3D2 color=3Dnavy face=3DArial><span =
style=3D'font-size:
10.0pt;font-family:Arial;color:navy'>Jon<o:p></o:p></span></font></p>
<p class=3DMsoNormal><font size=3D2 color=3Dnavy face=3DArial><span =
style=3D'font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
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<p class=3DMsoNormal><b><font size=3D2 face=3DTahoma><span =
style=3D'font-size:10.0pt;
font-family:Tahoma;font-weight:bold'>From:</span></font></b><font =
size=3D2
face=3DTahoma><span style=3D'font-size:10.0pt;font-family:Tahoma'>
pgsql-general-owner@[EMAIL PROTECTED]
=
[mailto:pgsql-general-owner@[EMAIL PROTECTED]
<b><span
style=3D'font-weight:bold'>On Behalf Of </span></b>Mike Gould<br>
<b><span style=3D'font-weight:bold'>Sent:</span></b> Monday, June 23, =
2008 1:01
PM<br>
<b><span style=3D'font-weight:bold'>To:</span></b> pgsql-general =
General<br>
<b><span style=3D'font-weight:bold'>Subject:</span></b> [GENERAL] Data =
Types</span></font><o:p></o:p></p>
</div>
<p class=3DMsoNormal><font size=3D3 face=3D"Times New Roman"><span =
style=3D'font-size:
12.0pt'><o:p> </o:p></span></font></p>
<p class=3DMsoNormal><font size=3D2 face=3DTahoma><span =
style=3D'font-size:10.0pt;
font-family:Tahoma'>We are converting our system from using Sybase's SQL
Anywhere 10 to PostGres 8.3. In SQL Anywhere there technically =
isn't any
difference in how a char and varchar is stored. They are all an array of
char[1]. So we always just defined everything as a char since right =
truncation
is the default.<br>
<br>
In PostGres though if we are using a character type column to search =
should we
define that as a varchar or a char or does it make any difference?<br>
<br>
Best Regards<br>
<br>
Michael Gould<br>
Intermodal Software Solutions, LLC.<o:p></o:p></span></font></p>
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