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

diff --git a/doc/FAQ b/doc/FAQ
index 403808f7bffc51f87d3d6114ab4825cca1123054..11a4783ab8755edea8dddeb86cede41e6bf4bc51 100644 (file)
--- a/doc/FAQ
+++ b/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?
     

diff --git a/doc/src/FAQ/FAQ.html b/doc/src/FAQ/FAQ.html
index 585807e6ab99254fae64a88e21b367c312170341..1123086be9a60b59216afc439493fd69da88a7d9 100644 (file)
--- a/doc/src/FAQ/FAQ.html
+++ b/doc/src/FAQ/FAQ.html
@@ -534,7 +534,7 @@ A report generator? An embedded query language interface?
 
 We have a nice graphical user interface called pgaccess, which is
 shipped as part of the distribution.  Pgaccess also has a report
-generator.  The Web page is 
+generator.  The Web page is ""
 "http://www.flex.ro/pgaccess">http://www.flex.ro/pgaccess
 
 We also include ecpg, which is an embedded SQL query language interface for
@@ -996,20 +996,18 @@ 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.
+   
+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.
 
 
 4.16.1) How do I create a