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| 1 # Run this TCL script using "testfixture" to get a report that shows |
| 2 # the sequence of database pages used by a particular table or index. |
| 3 # This information is used for fragmentation analysis. |
| 4 # |
| 5 |
| 6 # Get the name of the database to analyze |
| 7 # |
| 8 |
| 9 if {[llength $argv]!=2} { |
| 10 puts stderr "Usage: $argv0 database-name table-or-index-name" |
| 11 exit 1 |
| 12 } |
| 13 set file_to_analyze [lindex $argv 0] |
| 14 if {![file exists $file_to_analyze]} { |
| 15 puts stderr "No such file: $file_to_analyze" |
| 16 exit 1 |
| 17 } |
| 18 if {![file readable $file_to_analyze]} { |
| 19 puts stderr "File is not readable: $file_to_analyze" |
| 20 exit 1 |
| 21 } |
| 22 if {[file size $file_to_analyze]<512} { |
| 23 puts stderr "Empty or malformed database: $file_to_analyze" |
| 24 exit 1 |
| 25 } |
| 26 set objname [lindex $argv 1] |
| 27 |
| 28 # Open the database |
| 29 # |
| 30 sqlite3 db [lindex $argv 0] |
| 31 set DB [btree_open [lindex $argv 0] 1000 0] |
| 32 |
| 33 # This proc is a wrapper around the btree_cursor_info command. The |
| 34 # second argument is an open btree cursor returned by [btree_cursor]. |
| 35 # The first argument is the name of an array variable that exists in |
| 36 # the scope of the caller. If the third argument is non-zero, then |
| 37 # info is returned for the page that lies $up entries upwards in the |
| 38 # tree-structure. (i.e. $up==1 returns the parent page, $up==2 the |
| 39 # grandparent etc.) |
| 40 # |
| 41 # The following entries in that array are filled in with information retrieved |
| 42 # using [btree_cursor_info]: |
| 43 # |
| 44 # $arrayvar(page_no) = The page number |
| 45 # $arrayvar(entry_no) = The entry number |
| 46 # $arrayvar(page_entries) = Total number of entries on this page |
| 47 # $arrayvar(cell_size) = Cell size (local payload + header) |
| 48 # $arrayvar(page_freebytes) = Number of free bytes on this page |
| 49 # $arrayvar(page_freeblocks) = Number of free blocks on the page |
| 50 # $arrayvar(payload_bytes) = Total payload size (local + overflow) |
| 51 # $arrayvar(header_bytes) = Header size in bytes |
| 52 # $arrayvar(local_payload_bytes) = Local payload size |
| 53 # $arrayvar(parent) = Parent page number |
| 54 # |
| 55 proc cursor_info {arrayvar csr {up 0}} { |
| 56 upvar $arrayvar a |
| 57 foreach [list a(page_no) \ |
| 58 a(entry_no) \ |
| 59 a(page_entries) \ |
| 60 a(cell_size) \ |
| 61 a(page_freebytes) \ |
| 62 a(page_freeblocks) \ |
| 63 a(payload_bytes) \ |
| 64 a(header_bytes) \ |
| 65 a(local_payload_bytes) \ |
| 66 a(parent) \ |
| 67 a(first_ovfl) ] [btree_cursor_info $csr $up] break |
| 68 } |
| 69 |
| 70 # Determine the page-size of the database. This global variable is used |
| 71 # throughout the script. |
| 72 # |
| 73 set pageSize [db eval {PRAGMA page_size}] |
| 74 |
| 75 # Find the root page of table or index to be analyzed. Also find out |
| 76 # if the object is a table or an index. |
| 77 # |
| 78 if {$objname=="sqlite_master"} { |
| 79 set rootpage 1 |
| 80 set type table |
| 81 } else { |
| 82 db eval { |
| 83 SELECT rootpage, type FROM sqlite_master |
| 84 WHERE name=$objname |
| 85 } break |
| 86 if {![info exists rootpage]} { |
| 87 puts stderr "no such table or index: $objname" |
| 88 exit 1 |
| 89 } |
| 90 if {$type!="table" && $type!="index"} { |
| 91 puts stderr "$objname is something other than a table or index" |
| 92 exit 1 |
| 93 } |
| 94 if {![string is integer -strict $rootpage]} { |
| 95 puts stderr "invalid root page for $objname: $rootpage" |
| 96 exit 1 |
| 97 } |
| 98 } |
| 99 |
| 100 # The cursor $csr is pointing to an entry. Print out information |
| 101 # about the page that $up levels above that page that contains |
| 102 # the entry. If $up==0 use the page that contains the entry. |
| 103 # |
| 104 # If information about the page has been printed already, then |
| 105 # this is a no-op. |
| 106 # |
| 107 proc page_info {csr up} { |
| 108 global seen |
| 109 cursor_info ci $csr $up |
| 110 set pg $ci(page_no) |
| 111 if {[info exists seen($pg)]} return |
| 112 set seen($pg) 1 |
| 113 |
| 114 # Do parent pages first |
| 115 # |
| 116 if {$ci(parent)} { |
| 117 page_info $csr [expr {$up+1}] |
| 118 } |
| 119 |
| 120 # Find the depth of this page |
| 121 # |
| 122 set depth 1 |
| 123 set i $up |
| 124 while {$ci(parent)} { |
| 125 incr i |
| 126 incr depth |
| 127 cursor_info ci $csr $i |
| 128 } |
| 129 |
| 130 # print the results |
| 131 # |
| 132 puts [format {LEVEL %d: %6d} $depth $pg] |
| 133 } |
| 134 |
| 135 |
| 136 |
| 137 |
| 138 # Loop through the object and print out page numbers |
| 139 # |
| 140 set csr [btree_cursor $DB $rootpage 0] |
| 141 for {btree_first $csr} {![btree_eof $csr]} {btree_next $csr} { |
| 142 page_info $csr 0 |
| 143 set i 1 |
| 144 foreach pg [btree_ovfl_info $DB $csr] { |
| 145 puts [format {OVFL %3d: %6d} $i $pg] |
| 146 incr i |
| 147 } |
| 148 } |
| 149 exit 0 |
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