Update OID item description.

diff --git a/doc/FAQ b/doc/FAQ
index 528ed9cb910cecd82e5a31aedec4f218458ef585..447d30dc58258de218bfd4d04dc8e9fcde4b3c64 100644 (file)
--- a/doc/FAQ
+++ b/doc/FAQ
@@ -1,7 +1,7 @@
 
                 Frequently Asked Questions (FAQ) for PostgreSQL
                                        
-   Last updated: Wed Jan 19 14:45:22 EST 2005
+   Last updated: Sat Jan 29 21:05:17 EST 2005
    
    Current maintainer: Bruce Momjian (pgman@candle.pha.pa.us)
    
@@ -956,32 +956,16 @@ BYTEA           bytea           variable-length byte array (null-byte safe)
    
     4.15) What is an OID? What is a TID?
     
-   OIDs are PostgreSQL's answer to unique row ids. Every row that is
-   created in PostgreSQL gets a unique OID. All OIDs generated during
-   initdb are less than 16384 (from include/access/transam.h). All
-   user-created OIDs are equal to or greater than this. By default, all
-   these OIDs are unique not only within a table or database, but unique
-   within the entire PostgreSQL installation.
-   
-   PostgreSQL uses OIDs in its internal system tables to link rows
-   between tables. These OIDs can be used to identify specific user rows
-   and used in joins. It is recommended you use column type OID to store
-   OID values. You can create an index on the OID field for faster
-   access.
-   
-   OIDs are assigned to all new rows from a central area that is used by
-   all databases. If you want to change the OID to something else, or if
-   you want to make a copy of the table, with the original OIDs, there is
-   no reason you can't do it:
-        CREATE TABLE new_table(mycol int);
-        SELECT oid AS old_oid, mycol INTO tmp_table FROM old_table;
-        COPY tmp_table TO '/tmp/pgtable';
-        COPY new_table WITH OIDS FROM '/tmp/pgtable';
-        DROP TABLE tmp_table;
-
-   OIDs are stored as 4-byte integers, and will overflow at 4 billion. No
-   one has reported this ever happening, and we plan to have the limit
-   removed before anyone does.
+   Every row that is created in PostgreSQL gets a unique OID unless
+   created WITHOUT OIDS. OIDs are autotomatically assigned unique 4-byte
+   integers that are unique across the entire installation. However, they
+   overflow at 4 billion, and then the OIDs start being duplicated.
+   PostgreSQL uses OIDs to link its internal system tables together.
+   
+   To uniquely number columns in user tables, it is best to use SERIAL
+   rather than OIDs because SERIAL sequences are unique only within a
+   single table. and are therefore less likely to overflow. SERIAL8 is
+   available for storing eight-byte sequence values.
    
    TIDs are used to identify specific physical rows with block and offset
    values. TIDs change after rows are modified or reloaded. They are used

diff --git a/doc/src/FAQ/FAQ.html b/doc/src/FAQ/FAQ.html
index ec6a92b960a52285a81169650f41231cc50298f7..37e2ec37b4f77891d24e29caf0fcabb75560e9e0 100644 (file)
--- a/doc/src/FAQ/FAQ.html
+++ b/doc/src/FAQ/FAQ.html
@@ -10,7 +10,7 @@
   alink="#0000ff">
     <H1>Frequently Asked Questions (FAQ) for PostgreSQL</H1>
 
-    <P>Last updated: Wed Jan 19 14:45:22 EST 2005</P>
+    <P>Last updated: Sat Jan 29 21:05:17 EST 2005</P>
 
     <P>Current maintainer: Bruce Momjian (<A href=
     "mailto:pgman@candle.pha.pa.us">pgman@candle.pha.pa.us</A>)<BR>
@@ -1190,37 +1190,20 @@ BYTEA           bytea           variable-length byte array (null-byte safe)
     <H4><A name="4.15">4.15</A>) What is an <SMALL>OID</SMALL>? What is
     a <SMALL>TID</SMALL>?</H4>
 
-    <P><SMALL>OID</SMALL>s are PostgreSQL's answer to unique row ids.
-    Every row that is created in PostgreSQL gets a unique
-    <SMALL>OID</SMALL>. All <SMALL>OID</SMALL>s generated during
-    <I>initdb</I> are less than 16384 (from
-    <I>include/access/transam.h</I>). All user-created
-    <SMALL>OID</SMALL>s are equal to or greater than this. By default,
-    all these <SMALL>OID</SMALL>s are unique not only within a table or
-    database, but unique within the entire PostgreSQL installation.</P>
-
-    <P>PostgreSQL uses <SMALL>OID</SMALL>s in its internal system
-    tables to link rows between tables. These <SMALL>OID</SMALL>s can
-    be used to identify specific user rows and used in joins. It is
-    recommended you use column type <SMALL>OID</SMALL> to store
-    <SMALL>OID</SMALL> values. You can create an index on the
-    <SMALL>OID</SMALL> field for faster access.</P>
-
-    <P>O<SMALL>ID</SMALL>s are assigned to all new rows from a central
-    area that is used by all databases. If you want to change the
-    <SMALL>OID</SMALL> to something else, or if you want to make a copy
-    of the table, with the original <SMALL>OID</SMALL>s, there is no
-    reason you can't do it:</P>
-<PRE>
-        CREATE TABLE new_table(mycol int);
-        SELECT oid AS old_oid, mycol INTO tmp_table FROM old_table;
-        COPY tmp_table TO '/tmp/pgtable';
-        COPY new_table WITH OIDS FROM '/tmp/pgtable';
-        DROP TABLE tmp_table;
-</PRE>
-    <P>O<SMALL>ID</SMALL>s are stored as 4-byte integers, and will
-    overflow at 4 billion. No one has reported this ever happening, and
-    we plan to have the limit removed before anyone does.</P>
+    <P>Every row that is created in PostgreSQL gets a unique
+    <SMALL>OID</SMALL> unless created <SMALL>WITHOUT OIDS</SMALL>.
+    O<SMALL>ID</SMALL>s are autotomatically assigned unique 4-byte
+    integers that are unique across the entire installation.  However,
+    they overflow at 4 billion, and then the O<SMALL>ID</SMALL>s start
+    being duplicated. PostgreSQL uses <SMALL>OID</SMALL>s to link its
+    internal system tables together.</P>
+
+    <P>To uniquely number columns in user tables, it is best to use
+    <SMALL>SERIAL</> rather than O<SMALL>ID</SMALL>s because
+    <SMALL>SERIAL<SMALL> sequences are unique only within a single
+    table. and are therefore less likely to overflow.
+    <SMALL>SERIAL8</SMALL> is available for storing eight-byte sequence
+    values.</P>
 
     <P>T<SMALL>ID</SMALL>s are used to identify specific physical rows
     with block and offset values. T<SMALL>ID</SMALL>s change after rows