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Doc updates from Darren on char2-16 removal

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This commit is contained in:
Bruce Momjian 1998-04-26 04:18:06 +00:00
parent 0d203b745d
commit d31736e92b
6 changed files with 35 additions and 48 deletions
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8
doc/FAQ
View File

@ -543,7 +543,7 @@ Section 3: PostgreSQL Features
jolly=>
The fields in pg_group are:
* groname: the group name. This a char16 and should be purely
* groname: the group name. This a name and should be purely
alphanumeric. Do not include underscores or other punctuation.
* grosysid: the group id. This is an int4. This should be unique for
each group.
@ -622,11 +622,7 @@ Section 3: PostgreSQL Features
Type Internal Name Notes
--------------------------------------------------
CHAR char 1 character }
CHAR2 char2 2 characters }
CHAR4 char4 4 characters } optimized for a fixed length
CHAR8 char8 8 characters }
CHAR16 char16 16 characters }
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 tuple length

4
doc/src/sgml/advanced.sgml
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@ -126,7 +126,7 @@ SELECT c.name, c.altitude
CREATE TABLE SAL_EMP (
name text,
pay_by_quarter int4[],
schedule char16[][]
schedule text[][]
);
</ProgramListing>
</Para>
@ -135,7 +135,7 @@ CREATE TABLE SAL_EMP (
The above query will create a class named SAL_EMP with
a <FirstTerm>text</FirstTerm> string (name), a one-dimensional array of <FirstTerm>int4</FirstTerm>
(pay_by_quarter), which represents the employee's
salary by quarter and a two-dimensional array of <FirstTerm>char16</FirstTerm>
salary by quarter and a two-dimensional array of <FirstTerm>text</FirstTerm>
(schedule), which represents the employee's weekly
schedule. Now we do some <FirstTerm>INSERTS</FirstTerm>s; note that when
appending to an array, we enclose the values within

4
doc/src/sgml/array.sgml
View File

@ -20,7 +20,7 @@ This must become a chapter on array behavior. Volunteers? - thomas 1998-01-12
CREATE TABLE SAL_EMP (
name text,
pay_by_quarter int4[],
schedule char16[][]
schedule text[][]
);
</ProgramListing>
</Para>
@ -29,7 +29,7 @@ CREATE TABLE SAL_EMP (
The above query will create a class named SAL_EMP with
a <FirstTerm>text</FirstTerm> string (name), a one-dimensional array of <FirstTerm>int4</FirstTerm>
(pay_by_quarter), which represents the employee's
salary by quarter and a two-dimensional array of <FirstTerm>char16</FirstTerm>
salary by quarter and a two-dimensional array of <FirstTerm>text</FirstTerm>
(schedule), which represents the employee's weekly
schedule. Now we do some <FirstTerm>INSERTS</FirstTerm>s; note that when
appending to an array, we enclose the values within

30
doc/src/sgml/datatype.sgml
View File

@ -368,13 +368,16 @@ limit to be declared on the size of the field.
</Para>
<Para>
There are currently other fixed-length character types. These provide no additional
functionality and are likely to be deprecated in the future.
There is currently one other fixed-length character type. The <Type>name</Type> type
only has one purpose and that is to provide <ProductName>Postgres</ProductName> with a
special type to use for internal names. It is not intended for use by the general user.
It's length is currently defined as 32 chars but should be reference using NAMEDATALEN.
This is set at compile time and may change in any future release.
</Para>
<Para>
<TABLE TOCENTRY="1">
<TITLE><ProductName>Postgres</ProductName> Specialty Character Types</TITLE>
<TITLE><ProductName>Postgres</ProductName> Specialty Character Type</TITLE>
<TITLEABBREV>Specialty Characters</TITLEABBREV>
<TGROUP COLS="3">
<THEAD>
@ -386,24 +389,9 @@ functionality and are likely to be deprecated in the future.
</THEAD>
<TBODY>
<ROW>
<ENTRY>char2</ENTRY>
<ENTRY>2 bytes</ENTRY>
<ENTRY>Two characters</ENTRY>
</ROW>
<ROW>
<ENTRY>char4</ENTRY>
<ENTRY>4 bytes</ENTRY>
<ENTRY>Four characters</ENTRY>
</ROW>
<ROW>
<ENTRY>char8</ENTRY>
<ENTRY>8 bytes</ENTRY>
<ENTRY>Eight characters</ENTRY>
</ROW>
<ROW>
<ENTRY>char16</ENTRY>
<ENTRY>16 bytes</ENTRY>
<ENTRY>Sixteen characters</ENTRY>
<ENTRY>name</ENTRY>
<ENTRY>32 bytes</ENTRY>
<ENTRY>Thirty-two character internal type</ENTRY>
</ROW>
</TBODY>
</TGROUP>

2
doc/src/sgml/libpq.sgml
View File

@ -736,7 +736,7 @@ void PQputline(PGconn *conn,
int PQendcopy(PGconn *conn);
</ProgramListing>
<ProgramListing>
PQexec(conn, "create table foo (a int4, b char16, d float8)");
PQexec(conn, "create table foo (a int4, b text, d float8)");
PQexec(conn, "copy foo from stdin");
PQputline(conn, "3&lt;TAB&gt;hello world&lt;TAB&gt;4.5\n");
PQputline(conn,"4&lt;TAB&gt;goodbye world&lt;TAB&gt;7.11\n");

35
doc/src/sgml/xfunc.sgml
View File

@ -136,7 +136,7 @@
AS 'SELECT \'None\'::text AS name,
1000 AS salary,
25 AS age,
\'none\'::char16 AS dept;'
\'none\'::text AS dept;'
LANGUAGE 'sql';
</ProgramListing>
@ -263,7 +263,7 @@ The reason why, in general, we must use the function
<Para>
On the other hand, fixed-length types of any size may
be passed by-reference. For example, here is a sample
implementation of the <ProductName>Postgres</ProductName> char16 type:
implementation of a <ProductName>Postgres</ProductName> type:
<ProgramListing>
/* 16-byte structure, passed by reference */
@ -305,7 +305,6 @@ The reason why, in general, we must use the function
structure, we might use a code fragment like this:
<ProgramListing>
#include "postgres.h"
#include "utils/palloc.h"
...
char buffer[40]; /* our source data */
...
@ -322,20 +321,23 @@ The reason why, in general, we must use the function
Suppose <FileName>funcs.c</FileName> look like:
<ProgramListing>
#include &lt;string.h&gt;
#include "postgres.h" /* for char16, etc. */
#include "utils/palloc.h" /* for palloc */
#include "postgres.h"
int
add_one(int arg)
{
return(arg + 1);
}
char16 *
concat16(char16 *arg1, char16 *arg2)
text *
concat_text(text *arg1, text *arg2)
{
char16 *new_c16 = (char16 *) palloc(sizeof(char16));
memset((void *) new_c16, 0, sizeof(char16));
(void) strncpy(new_c16, arg1, 16);
return (char16 *)(strncat(new_c16, arg2, 16));
int32 new_text_size = VARSIZE(arg1) + VARSIZE(arg2) - VARHDRSZ;
text *new_text = (text *) palloc(new_text_size);
memset((void *) new_text, 0, new_text_size);
VARSIZE(new_text) = new_text_size;
strncpy(VARDATA(new_text), VARDATA(arg1), VARSIZE(arg1)-VARHDRSZ);
strncat(VARDATA(new_text), VARDATA(arg2), VARSIZE(arg2)-VARHDRSZ);
return (new_text);
}
text *
copytext(text *t)
@ -364,7 +366,7 @@ The reason why, in general, we must use the function
CREATE FUNCTION add_one(int4) RETURNS int4
AS 'PGROOT/tutorial/obj/funcs.so' LANGUAGE 'c';
CREATE FUNCTION concat16(char16, char16) RETURNS char16
CREATE FUNCTION concat_text(text, text) RETURNS text
AS 'PGROOT/tutorial/obj/funcs.so' LANGUAGE 'c';
CREATE FUNCTION copytext(text) RETURNS text
@ -401,7 +403,7 @@ The reason why, in general, we must use the function
In the query above, we can define c_overpaid as:
<ProgramListing>
#include "postgres.h" /* for char16, etc. */
#include "postgres.h"
#include "libpq-fe.h" /* for TUPLE */
bool
c_overpaid(TUPLE t,/* the current instance of EMP */
@ -426,7 +428,7 @@ The reason why, in general, we must use the function
is null. <Acronym>GetAttributeByName</Acronym> will align data properly
so you can cast its return value to the desired type.
For example, if you have an attribute name which is of
the type char16, the <Acronym>GetAttributeByName</Acronym> call would look
the type name, the <Acronym>GetAttributeByName</Acronym> call would look
like:
<ProgramListing>
char *str;
@ -517,8 +519,9 @@ Most of the header (include) files for <ProductName>Postgres</ProductName>
</Para>
<ListItem>
<Para> Most of the internal <ProductName>Postgres</ProductName> types are declared
in postgres.h, so it's usually a good idea to
include that file as well.
in postgres.h, so it's a good idea to always
include that file as well. Including postgres.h
will also include elog.h and palloc.h for you.
</Para>
<ListItem>
<Para> Compiling and loading your object code so that