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authorHans-Christoph Steiner <hans@eds.org>2012-03-30 20:42:12 -0400
committerHans-Christoph Steiner <hans@eds.org>2012-03-30 20:42:12 -0400
commit7bb481fda9ecb134804b49c2ce77ca28f7eea583 (patch)
tree31b520b9914d3e2453968abe375f2c102772c3dc /tool/fragck.tcl
Imported Upstream version 2.0.3
Diffstat (limited to 'tool/fragck.tcl')
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+# Run this TCL script using "testfixture" to get a report that shows
+# the sequence of database pages used by a particular table or index.
+# This information is used for fragmentation analysis.
+#
+
+# Get the name of the database to analyze
+#
+
+if {[llength $argv]!=2} {
+ puts stderr "Usage: $argv0 database-name table-or-index-name"
+ exit 1
+}
+set file_to_analyze [lindex $argv 0]
+if {![file exists $file_to_analyze]} {
+ puts stderr "No such file: $file_to_analyze"
+ exit 1
+}
+if {![file readable $file_to_analyze]} {
+ puts stderr "File is not readable: $file_to_analyze"
+ exit 1
+}
+if {[file size $file_to_analyze]<512} {
+ puts stderr "Empty or malformed database: $file_to_analyze"
+ exit 1
+}
+set objname [lindex $argv 1]
+
+# Open the database
+#
+sqlite3 db [lindex $argv 0]
+set DB [btree_open [lindex $argv 0] 1000 0]
+
+# This proc is a wrapper around the btree_cursor_info command. The
+# second argument is an open btree cursor returned by [btree_cursor].
+# The first argument is the name of an array variable that exists in
+# the scope of the caller. If the third argument is non-zero, then
+# info is returned for the page that lies $up entries upwards in the
+# tree-structure. (i.e. $up==1 returns the parent page, $up==2 the
+# grandparent etc.)
+#
+# The following entries in that array are filled in with information retrieved
+# using [btree_cursor_info]:
+#
+# $arrayvar(page_no) = The page number
+# $arrayvar(entry_no) = The entry number
+# $arrayvar(page_entries) = Total number of entries on this page
+# $arrayvar(cell_size) = Cell size (local payload + header)
+# $arrayvar(page_freebytes) = Number of free bytes on this page
+# $arrayvar(page_freeblocks) = Number of free blocks on the page
+# $arrayvar(payload_bytes) = Total payload size (local + overflow)
+# $arrayvar(header_bytes) = Header size in bytes
+# $arrayvar(local_payload_bytes) = Local payload size
+# $arrayvar(parent) = Parent page number
+#
+proc cursor_info {arrayvar csr {up 0}} {
+ upvar $arrayvar a
+ foreach [list a(page_no) \
+ a(entry_no) \
+ a(page_entries) \
+ a(cell_size) \
+ a(page_freebytes) \
+ a(page_freeblocks) \
+ a(payload_bytes) \
+ a(header_bytes) \
+ a(local_payload_bytes) \
+ a(parent) \
+ a(first_ovfl) ] [btree_cursor_info $csr $up] break
+}
+
+# Determine the page-size of the database. This global variable is used
+# throughout the script.
+#
+set pageSize [db eval {PRAGMA page_size}]
+
+# Find the root page of table or index to be analyzed. Also find out
+# if the object is a table or an index.
+#
+if {$objname=="sqlite_master"} {
+ set rootpage 1
+ set type table
+} else {
+ db eval {
+ SELECT rootpage, type FROM sqlite_master
+ WHERE name=$objname
+ } break
+ if {![info exists rootpage]} {
+ puts stderr "no such table or index: $objname"
+ exit 1
+ }
+ if {$type!="table" && $type!="index"} {
+ puts stderr "$objname is something other than a table or index"
+ exit 1
+ }
+ if {![string is integer -strict $rootpage]} {
+ puts stderr "invalid root page for $objname: $rootpage"
+ exit 1
+ }
+}
+
+# The cursor $csr is pointing to an entry. Print out information
+# about the page that $up levels above that page that contains
+# the entry. If $up==0 use the page that contains the entry.
+#
+# If information about the page has been printed already, then
+# this is a no-op.
+#
+proc page_info {csr up} {
+ global seen
+ cursor_info ci $csr $up
+ set pg $ci(page_no)
+ if {[info exists seen($pg)]} return
+ set seen($pg) 1
+
+ # Do parent pages first
+ #
+ if {$ci(parent)} {
+ page_info $csr [expr {$up+1}]
+ }
+
+ # Find the depth of this page
+ #
+ set depth 1
+ set i $up
+ while {$ci(parent)} {
+ incr i
+ incr depth
+ cursor_info ci $csr $i
+ }
+
+ # print the results
+ #
+ puts [format {LEVEL %d: %6d} $depth $pg]
+}
+
+
+
+
+# Loop through the object and print out page numbers
+#
+set csr [btree_cursor $DB $rootpage 0]
+for {btree_first $csr} {![btree_eof $csr]} {btree_next $csr} {
+ page_info $csr 0
+ set i 1
+ foreach pg [btree_ovfl_info $DB $csr] {
+ puts [format {OVFL %3d: %6d} $i $pg]
+ incr i
+ }
+}
+exit 0