Remove obsolete claim that char(n) is more efficient than other text types.

Author: tglsfdc

doc/FAQ

@@ -811,19 +811,17 @@ Type            Internal Name   Notes
 "char"          char            1 character
 CHAR(#)         bpchar          blank padded to the specified fixed length
 VARCHAR(#)      varchar         size specifies maximum length, no padding
-TEXT            text            length limited only by maximum row length
-BYTEA           bytea           variable-length array of bytes
+TEXT            text            no specific upper limit on length
+BYTEA           bytea           variable-length byte array (null-safe)
 
    You will see the internal name when examining system catalogs and in
    some error messages.
 
    The last four types above are "varlena" types (i.e., the first four
-   bytes are the length, followed by the data). char(#) allocates the
-   maximum number of bytes no matter how much data is stored in the
-   field. text, varchar(#), and bytea all have variable length on the
-   disk, and because of this, there is a small performance penalty for
-   using them. Specifically, the penalty is for access to all columns
-   after the first column of this type.
+   bytes on disk are the length, followed by the data).  Thus the actual
+   space used is slightly greater than the declared size.  However, these
+   data types are also subject to compression or being stored out-of-line
+   by TOAST, so the space on disk might also be less than expected.
 
     4.16.1) How do I create a serial/auto-incrementing field?
 

doc/src/FAQ/FAQ.html

@@ -534,7 +534,7 @@ <H4><A NAME="2.3">2.3</A>) Does PostgreSQL have a graphical user interface?
 
 We have a nice graphical user interface called <I>pgaccess,</I> which is
 shipped as part of the distribution.  <I>Pgaccess</I> also has a report
-generator.  The Web page is <A HREF=
+generator.  The Web page is <A HREF=""
 "http://www.flex.ro/pgaccess">http://www.flex.ro/pgaccess</A><P>
 
 We also include <I>ecpg,</I> which is an embedded SQL query language interface for
@@ -996,20 +996,18 @@ <H4><A NAME="4.15">4.15</A>) What is the difference between the
 "char"          char            1 character
 CHAR(#)         bpchar          blank padded to the specified fixed length
 VARCHAR(#)      varchar         size specifies maximum length, no padding
-TEXT            text            length limited only by maximum row length
-BYTEA           bytea           variable-length array of bytes
+TEXT            text            no specific upper limit on length
+BYTEA           bytea           variable-length byte array (null-safe)
 </PRE><P>
 
 You will see the internal name when examining system catalogs
 and in some error messages.<P>
-
-The last four types above are "varlena" types (i.e., the first four bytes
-are the length, followed by the data). <I>char(#)</I> allocates the
-maximum number of bytes no matter how much data is stored in the field.
-<I>text, varchar(#),</I> and <I>bytea</I> all have variable length on the disk,
-and because of this, there is a small performance penalty for using
-them. Specifically, the penalty is for access to all columns after the
-first column of this type.<P>
+   
+The last four types above are "varlena" types (i.e., the first four
+bytes on disk are the length, followed by the data).  Thus the actual
+space used is slightly greater than the declared size.  However, these
+data types are also subject to compression or being stored out-of-line
+by TOAST, so the space on disk might also be less than expected.<P>
 
 
 <H4><A NAME="4.16.1">4.16.1</A>) How do I create a