xref: /titanic_41/usr/src/lib/libsqlite/tool/space_used.tcl (revision 5cff782560a1c3cf913ba5574a5123a299f3315e)
1
2#pragma ident	"%Z%%M%	%I%	%E% SMI"
3
4# Run this TCL script using "testfixture" in order get a report that shows
5# how much disk space is used by a particular data to actually store data
6# versus how much space is unused.
7#
8
9# Get the name of the database to analyze
10#
11if {[llength $argv]!=1} {
12  puts stderr "Usage: $argv0 database-name"
13  exit 1
14}
15set file_to_analyze [lindex $argv 0]
16
17# Open the database
18#
19sqlite db [lindex $argv 0]
20set DB [btree_open [lindex $argv 0]]
21
22# Output the schema for the generated report
23#
24puts \
25{BEGIN;
26CREATE TABLE space_used(
27   name clob,        -- Name of a table or index in the database file
28   is_index boolean, -- TRUE if it is an index, false for a table
29   payload int,      -- Total amount of data stored in this table or index
30   pri_pages int,    -- Number of primary pages used
31   ovfl_pages int,   -- Number of overflow pages used
32   pri_unused int,   -- Number of unused bytes on primary pages
33   ovfl_unused int   -- Number of unused bytes on overflow pages
34);}
35
36# This query will be used to find the root page number for every index and
37# table in the database.
38#
39set sql {
40  SELECT name, type, rootpage FROM sqlite_master
41  UNION ALL
42  SELECT 'sqlite_master', 'table', 2
43  ORDER BY 1
44}
45
46# Initialize variables used for summary statistics.
47#
48set total_size 0
49set total_primary 0
50set total_overflow 0
51set total_unused_primary 0
52set total_unused_ovfl 0
53
54# Analyze every table in the database, one at a time.
55#
56foreach {name type rootpage} [db eval $sql] {
57  set cursor [btree_cursor $DB $rootpage 0]
58  set go [btree_first $cursor]
59  set size 0
60  catch {unset pg_used}
61  set unused_ovfl 0
62  set n_overflow 0
63  while {$go==0} {
64    set payload [btree_payload_size $cursor]
65    incr size $payload
66    set stat [btree_cursor_dump $cursor]
67    set pgno [lindex $stat 0]
68    set freebytes [lindex $stat 4]
69    set pg_used($pgno) $freebytes
70    if {$payload>238} {
71      set n [expr {($payload-238+1019)/1020}]
72      incr n_overflow $n
73      incr unused_ovfl [expr {$n*1020+238-$payload}]
74    }
75    set go [btree_next $cursor]
76  }
77  btree_close_cursor $cursor
78  set n_primary [llength [array names pg_used]]
79  set unused_primary 0
80  foreach x [array names pg_used] {incr unused_primary $pg_used($x)}
81  regsub -all ' $name '' name
82  puts -nonewline "INSERT INTO space_used VALUES('$name'"
83  puts -nonewline ",[expr {$type=="index"}]"
84  puts ",$size,$n_primary,$n_overflow,$unused_primary,$unused_ovfl);"
85  incr total_size $size
86  incr total_primary $n_primary
87  incr total_overflow $n_overflow
88  incr total_unused_primary $unused_primary
89  incr total_unused_ovfl $unused_ovfl
90}
91
92# Output summary statistics:
93#
94puts "-- Total payload size: $total_size"
95puts "-- Total pages used: $total_primary primary and $total_overflow overflow"
96set file_pgcnt [expr {[file size [lindex $argv 0]]/1024}]
97puts -nonewline "-- Total unused bytes on primary pages: $total_unused_primary"
98if {$total_primary>0} {
99  set upp [expr {$total_unused_primary/$total_primary}]
100  puts " (avg $upp bytes/page)"
101} else {
102  puts ""
103}
104puts -nonewline "-- Total unused bytes on overflow pages: $total_unused_ovfl"
105if {$total_overflow>0} {
106  set upp [expr {$total_unused_ovfl/$total_overflow}]
107  puts " (avg $upp bytes/page)"
108} else {
109  puts ""
110}
111set n_free [expr {$file_pgcnt-$total_primary-$total_overflow}]
112if {$n_free>0} {incr n_free -1}
113puts "-- Total pages on freelist: $n_free"
114puts "COMMIT;"
115