# 2010 September 24 # # The author disclaims copyright to this source code. In place of # a legal notice, here is a blessing: # # May you do good and not evil. # May you find forgiveness for yourself and forgive others. # May you share freely, never taking more than you give. # #*********************************************************************** # # This file implements tests to verify that the "testable statements" in # the lang_vacuum.html document are correct. # set testdir [file dirname $argv0] source $testdir/tester.tcl sqlite3_test_control_pending_byte 0x1000000 proc create_db {{sql ""}} { catch { db close } forcedelete test.db sqlite3 db test.db db transaction { execsql { PRAGMA page_size = 1024; } execsql $sql execsql { CREATE TABLE t1(a PRIMARY KEY, b UNIQUE); INSERT INTO t1 VALUES(1, randomblob(400)); INSERT INTO t1 SELECT a+1, randomblob(400) FROM t1; INSERT INTO t1 SELECT a+2, randomblob(400) FROM t1; INSERT INTO t1 SELECT a+4, randomblob(400) FROM t1; INSERT INTO t1 SELECT a+8, randomblob(400) FROM t1; INSERT INTO t1 SELECT a+16, randomblob(400) FROM t1; INSERT INTO t1 SELECT a+32, randomblob(400) FROM t1; INSERT INTO t1 SELECT a+64, randomblob(400) FROM t1; CREATE TABLE t2(a PRIMARY KEY, b UNIQUE); INSERT INTO t2 SELECT * FROM t1; } } return [expr {[file size test.db] / 1024}] } # This proc returns the number of contiguous blocks of pages that make up # the table or index named by the only argument. For example, if the table # occupies database pages 3, 4, 8 and 9, then this command returns 2 (there # are 2 fragments - one consisting of pages 3 and 4, the other of fragments # 8 and 9). # proc fragment_count {name} { execsql { CREATE VIRTUAL TABLE temp.stat USING dbstat } set nFrag 1 db eval {SELECT pageno FROM stat WHERE name = 't1' ORDER BY pageno} { if {[info exists prevpageno] && $prevpageno != $pageno-1} { incr nFrag } set prevpageno $pageno } execsql { DROP TABLE temp.stat } set nFrag } # EVIDENCE-OF: R-63707-33375 -- syntax diagram vacuum-stmt # do_execsql_test e_vacuum-0.1 { VACUUM } {} # EVIDENCE-OF: R-51469-36013 Unless SQLite is running in # "auto_vacuum=FULL" mode, when a large amount of data is deleted from # the database file it leaves behind empty space, or "free" database # pages. # # EVIDENCE-OF: R-60541-63059 Running VACUUM to rebuild the database # reclaims this space and reduces the size of the database file. # foreach {tn avmode sz} { 1 none 7 2 full 8 3 incremental 8 } { set nPage [create_db "PRAGMA auto_vacuum = $avmode"] do_execsql_test e_vacuum-1.1.$tn.1 { DELETE FROM t1; DELETE FROM t2; } {} if {$avmode == "full"} { # This branch tests the "unless ... auto_vacuum=FULL" in the requirement # above. If auto_vacuum is set to FULL, then no empty space is left in # the database file. do_execsql_test e_vacuum-1.1.$tn.2 {PRAGMA freelist_count} 0 } else { set freelist [expr {$nPage - $sz}] if {$avmode == "incremental"} { # The page size is 1024 bytes. Therefore, assuming the database contains # somewhere between 207 and 411 pages (it does), there are 2 pointer-map # pages. incr freelist -2 } do_execsql_test e_vacuum-1.1.$tn.3 {PRAGMA freelist_count} $freelist do_execsql_test e_vacuum-1.1.$tn.4 {VACUUM} {} } do_test e_vacuum-1.1.$tn.5 { expr {[file size test.db] / 1024} } $sz } # EVIDENCE-OF: R-50943-18433 Frequent inserts, updates, and deletes can # cause the database file to become fragmented - where data for a single # table or index is scattered around the database file. # # EVIDENCE-OF: R-05791-54928 Running VACUUM ensures that each table and # index is largely stored contiguously within the database file. # # e_vacuum-1.2.1 - Perform many INSERT, UPDATE and DELETE ops on table t1. # e_vacuum-1.2.2 - Verify that t1 and its indexes are now quite fragmented. # e_vacuum-1.2.3 - Run VACUUM. # e_vacuum-1.2.4 - Verify that t1 and its indexes are now much # less fragmented. # ifcapable vtab { create_db register_dbstat_vtab db do_execsql_test e_vacuum-1.2.1 { DELETE FROM t1 WHERE a%2; INSERT INTO t1 SELECT b, a FROM t2 WHERE a%2; UPDATE t1 SET b=randomblob(600) WHERE (a%2)==0; } {} do_test e_vacuum-1.2.2.1 { expr [fragment_count t1]>100 } 1 do_test e_vacuum-1.2.2.2 { expr [fragment_count sqlite_autoindex_t1_1]>100 } 1 do_test e_vacuum-1.2.2.3 { expr [fragment_count sqlite_autoindex_t1_2]>100 } 1 do_execsql_test e_vacuum-1.2.3 { VACUUM } {} # In practice, the tables and indexes each end up stored as two fragments - # one containing the root page and another containing all other pages. # do_test e_vacuum-1.2.4.1 { fragment_count t1 } 2 do_test e_vacuum-1.2.4.2 { fragment_count sqlite_autoindex_t1_1 } 2 do_test e_vacuum-1.2.4.3 { fragment_count sqlite_autoindex_t1_2 } 2 } # EVIDENCE-OF: R-20474-44465 Normally, the database page_size and # whether or not the database supports auto_vacuum must be configured # before the database file is actually created. # do_test e_vacuum-1.3.1.1 { create_db "PRAGMA page_size = 1024 ; PRAGMA auto_vacuum = FULL" execsql { PRAGMA page_size ; PRAGMA auto_vacuum } } {1024 1} do_test e_vacuum-1.3.1.2 { execsql { PRAGMA page_size = 2048 } execsql { PRAGMA auto_vacuum = NONE } execsql { PRAGMA page_size ; PRAGMA auto_vacuum } } {1024 1} # EVIDENCE-OF: R-08570-19916 However, when not in write-ahead log mode, # the page_size and/or auto_vacuum properties of an existing database # may be changed by using the page_size and/or pragma auto_vacuum # pragmas and then immediately VACUUMing the database. # do_test e_vacuum-1.3.2.1 { execsql { PRAGMA journal_mode = delete } execsql { PRAGMA page_size = 2048 } execsql { PRAGMA auto_vacuum = NONE } execsql VACUUM execsql { PRAGMA page_size ; PRAGMA auto_vacuum } } {2048 0} # EVIDENCE-OF: R-48521-51450 When in write-ahead log mode, only the # auto_vacuum support property can be changed using VACUUM. # ifcapable wal { do_test e_vacuum-1.3.3.1 { execsql { PRAGMA journal_mode = wal } execsql { PRAGMA page_size ; PRAGMA auto_vacuum } } {2048 0} do_test e_vacuum-1.3.3.2 { execsql { PRAGMA page_size = 1024 } execsql { PRAGMA auto_vacuum = FULL } execsql VACUUM execsql { PRAGMA page_size ; PRAGMA auto_vacuum } } {2048 1} } # EVIDENCE-OF: R-38001-03952 VACUUM only works on the main database. It # is not possible to VACUUM an attached database file. forcedelete test.db2 create_db { PRAGMA auto_vacuum = NONE } do_execsql_test e_vacuum-2.1.1 { ATTACH 'test.db2' AS aux; PRAGMA aux.page_size = 1024; CREATE TABLE aux.t3 AS SELECT * FROM t1; DELETE FROM t3; } {} set original_size [file size test.db2] # Try everything we can think of to get the aux database vacuumed: do_execsql_test e_vacuum-2.1.3 { VACUUM } {} do_execsql_test e_vacuum-2.1.4 { VACUUM aux } {} do_execsql_test e_vacuum-2.1.5 { VACUUM 'test.db2' } {} # Despite our efforts, space in the aux database has not been reclaimed: do_test e_vacuum-2.1.6 { expr {[file size test.db2]==$::original_size} } 1 # EVIDENCE-OF: R-17495-17419 The VACUUM command may change the ROWIDs of # entries in any tables that do not have an explicit INTEGER PRIMARY # KEY. # # Tests e_vacuum-3.1.1 - 3.1.2 demonstrate that rowids can change when # a database is VACUUMed. Tests e_vacuum-3.1.3 - 3.1.4 show that adding # an INTEGER PRIMARY KEY column to a table stops this from happening. # do_execsql_test e_vacuum-3.1.1 { CREATE TABLE t4(x); INSERT INTO t4(x) VALUES('x'); INSERT INTO t4(x) VALUES('y'); INSERT INTO t4(x) VALUES('z'); DELETE FROM t4 WHERE x = 'y'; SELECT rowid, x FROM t4; } {1 x 3 z} do_execsql_test e_vacuum-3.1.2 { VACUUM; SELECT rowid, x FROM t4; } {1 x 2 z} do_execsql_test e_vacuum-3.1.3 { CREATE TABLE t5(x, y INTEGER PRIMARY KEY); INSERT INTO t5(x) VALUES('x'); INSERT INTO t5(x) VALUES('y'); INSERT INTO t5(x) VALUES('z'); DELETE FROM t5 WHERE x = 'y'; SELECT rowid, x FROM t5; } {1 x 3 z} do_execsql_test e_vacuum-3.1.4 { VACUUM; SELECT rowid, x FROM t5; } {1 x 3 z} # EVIDENCE-OF: R-49563-33883 A VACUUM will fail if there is an open # transaction, or if there are one or more active SQL statements when it # is run. # do_execsql_test e_vacuum-3.2.1.1 { BEGIN } {} do_catchsql_test e_vacuum-3.2.1.2 { VACUUM } {1 {cannot VACUUM from within a transaction}} do_execsql_test e_vacuum-3.2.1.3 { COMMIT } {} do_execsql_test e_vacuum-3.2.1.4 { VACUUM } {} do_execsql_test e_vacuum-3.2.1.5 { SAVEPOINT x } {} do_catchsql_test e_vacuum-3.2.1.6 { VACUUM } {1 {cannot VACUUM from within a transaction}} do_execsql_test e_vacuum-3.2.1.7 { COMMIT } {} do_execsql_test e_vacuum-3.2.1.8 { VACUUM } {} create_db do_test e_vacuum-3.2.2.1 { set res "" db eval { SELECT a FROM t1 } { if {$a == 10} { set res [catchsql VACUUM] } } set res } {1 {cannot VACUUM - SQL statements in progress}} # EVIDENCE-OF: R-38735-12540 As of SQLite version 3.1, an alternative to # using the VACUUM command to reclaim space after data has been deleted # is auto-vacuum mode, enabled using the auto_vacuum pragma. # do_test e_vacuum-3.3.1 { create_db { PRAGMA auto_vacuum = FULL } execsql { PRAGMA auto_vacuum } } {1} # EVIDENCE-OF: R-64844-34873 When auto_vacuum is enabled for a database # free pages may be reclaimed after deleting data, causing the file to # shrink, without rebuilding the entire database using VACUUM. # do_test e_vacuum-3.3.2.1 { create_db { PRAGMA auto_vacuum = FULL } execsql { DELETE FROM t1; DELETE FROM t2; } expr {[file size test.db] / 1024} } {8} do_test e_vacuum-3.3.2.2 { create_db { PRAGMA auto_vacuum = INCREMENTAL } execsql { DELETE FROM t1; DELETE FROM t2; PRAGMA incremental_vacuum; } expr {[file size test.db] / 1024} } {8} finish_test