Update tuple header size.

diff --git a/doc/FAQ b/doc/FAQ
index b054d06914fd30106873ebf8c2e59561e1964243..3b9ec250a2de3da78d336a12a1c4fdd2c1c806a2 100644 (file)
--- a/doc/FAQ
+++ b/doc/FAQ
@@ -1,7 +1,7 @@
 
                 Frequently Asked Questions (FAQ) for PostgreSQL
                                        
-   Last updated: Mon Jul 19 16:28:37 EDT 2004
+   Last updated: Mon Jul 26 23:27:08 EDT 2004
    
    Current maintainer: Bruce Momjian ([email protected])
    
@@ -735,23 +735,23 @@
    twenty bytes in length. The flat file would be 2.8 MB. The size of the
    PostgreSQL database file containing this data can be estimated as 6.4
    MB:
-    36 bytes: each row header (approximate)
+    32 bytes: each row header (approximate)
     24 bytes: one int field and one text field
    + 4 bytes: pointer on page to tuple
    ----------------------------------------
-    64 bytes per row
+    60 bytes per row
 
    The data page size in PostgreSQL is 8192 bytes (8 KB), so:
 
    8192 bytes per page
-   -------------------   =  128 rows per database page (rounded down)
-     64 bytes per row
+   -------------------   =  136 rows per database page (rounded down)
+     60 bytes per row
 
    100000 data rows
-   --------------------  =  782 database pages (rounded up)
+   --------------------  =  735 database pages (rounded up)
       128 rows per page
 
-782 database pages * 8192 bytes per page  =  6,406,144 bytes (6.4 MB)
+735 database pages * 8192 bytes per page  =  6,021,120 bytes (6 MB)
 
    Indexes do not require as much overhead, but do contain the data that
    is being indexed, so they can be large also.

diff --git a/doc/src/FAQ/FAQ.html b/doc/src/FAQ/FAQ.html
index c3e305c4255de0ca04b3518724fadb024d2b6c60..2272703f3c5efc7592ec1f1eb7f0a2216bdcdbdd 100644 (file)
--- a/doc/src/FAQ/FAQ.html
+++ b/doc/src/FAQ/FAQ.html
@@ -10,7 +10,7 @@
   alink="#0000ff">
     Frequently Asked Questions (FAQ) for PostgreSQL
 
-    Last updated: Mon Jul 19 16:28:37 EDT 2004
+    Last updated: Mon Jul 26 23:27:08 EDT 2004
 
     Current maintainer: Bruce Momjian (
     "mailto:[email protected]">[email protected])
@@ -927,23 +927,23 @@
     The size of the PostgreSQL database file containing this data can
     be estimated as 6.4 MB:
 
-    36 bytes: each row header (approximate)
+    32 bytes: each row header (approximate)
     24 bytes: one int field and one text field
    + 4 bytes: pointer on page to tuple
    ----------------------------------------
-    64 bytes per row
+    60 bytes per row
 
    The data page size in PostgreSQL is 8192 bytes (8 KB), so:
 
    8192 bytes per page
-   -------------------   =  128 rows per database page (rounded down)
-     64 bytes per row
+   -------------------   =  136 rows per database page (rounded down)
+     60 bytes per row
 
    100000 data rows
-   --------------------  =  782 database pages (rounded up)
+   --------------------  =  735 database pages (rounded up)
       128 rows per page
 
-782 database pages * 8192 bytes per page  =  6,406,144 bytes (6.4 MB)
+735 database pages * 8192 bytes per page  =  6,021,120 bytes (6 MB)
 
 
     Indexes do not require as much overhead, but do contain the data