# 2007 April 12 # # 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 regression tests for SQLite library. # The focus of the tests in this file are to verify that the # pager optimizations implemented in version 3.3.14 work. # # $Id: pageropt.test,v 1.1.1.1 2012/02/21 17:04:16 misho Exp $ set testdir [file dirname $argv0] source $testdir/tester.tcl ifcapable {!pager_pragmas||secure_delete||direct_read} { finish_test return } # Run the SQL statement supplied by the argument and return # the results. Prepend four integers to the beginning of the # result which are # # (1) The number of page reads from the database # (2) The number of page writes to the database # (3) The number of page writes to the journal # (4) The number of cache pages freed # proc pagercount_sql {sql {db db}} { global sqlite3_pager_readdb_count global sqlite3_pager_writedb_count global sqlite3_pager_writej_count global sqlite3_pager_pgfree_count set sqlite3_pager_readdb_count 0 set sqlite3_pager_writedb_count 0 set sqlite3_pager_writej_count 0 set r [$db eval $sql] set cnt [list $sqlite3_pager_readdb_count \ $sqlite3_pager_writedb_count \ $sqlite3_pager_writej_count ] return [concat $cnt $r] } # Setup the test database # do_test pageropt-1.1 { sqlite3_soft_heap_limit 0 execsql { PRAGMA auto_vacuum = OFF; PRAGMA page_size = 1024; } pagercount_sql { CREATE TABLE t1(x); } } {0 2 0} do_test pageropt-1.2 { pagercount_sql { INSERT INTO t1 VALUES(randomblob(5000)); } } {0 6 2} # Verify that values remain in cache on for subsequent reads. # We should not have to go back to disk. # do_test pageropt-1.3 { pagercount_sql { SELECT length(x) FROM t1 } } {0 0 0 5000} # If another thread reads the database, the original cache # remains valid. # sqlite3 db2 test.db set blobcontent [db2 one {SELECT hex(x) FROM t1}] do_test pageropt-1.4 { pagercount_sql { SELECT hex(x) FROM t1 } } [list 0 0 0 $blobcontent] # But if the other thread modifies the database, then the cache # must refill. # do_test pageropt-1.5 { db2 eval {CREATE TABLE t2(y)} pagercount_sql { SELECT hex(x) FROM t1 } } [list 6 0 0 $blobcontent] do_test pageropt-1.6 { pagercount_sql { SELECT hex(x) FROM t1 } } [list 0 0 0 $blobcontent] # Verify that the last page of an overflow chain is not read from # disk when deleting a row. The one row of t1(x) has four pages # of overflow. So deleting that row from t1 should involve reading # the sqlite_master table (1 page) the main page of t1 (1 page) and # the three overflow pages of t1 for a total of 5 pages. # # Pages written are page 1 (for the freelist pointer), the root page # of the table, and one of the overflow chain pointers because it # becomes the trunk of the freelist. Total 3. # do_test pageropt-2.1 { db close sqlite3 db test.db pagercount_sql { DELETE FROM t1 WHERE rowid=1 } } {5 3 3} # When pulling pages off of the freelist, there is no reason # to actually bring in the old content. # do_test pageropt-2.2 { db close sqlite3 db test.db pagercount_sql { INSERT INTO t1 VALUES(randomblob(1500)); } } {3 4 3} do_test pageropt-2.3 { pagercount_sql { INSERT INTO t1 VALUES(randomblob(1500)); } } {0 4 3} # Note the new optimization that when pulling the very last page off of the # freelist we do not read the content of that page. # do_test pageropt-2.4 { pagercount_sql { INSERT INTO t1 VALUES(randomblob(1500)); } } {0 5 3} # Appending a large quantity of data does not involve writing much # to the journal file. # do_test pageropt-3.1 { pagercount_sql { INSERT INTO t2 SELECT * FROM t1; } } {1 7 2} # Once again, we do not need to read the last page of an overflow chain # while deleting. # do_test pageropt-3.2 { pagercount_sql { DROP TABLE t2; } } {0 2 3} do_test pageropt-3.3 { pagercount_sql { DELETE FROM t1; } } {0 3 3} # There are now 11 pages on the freelist. Move them all into an # overflow chain by inserting a single large record. Starting from # a cold cache, only page 1, the root page of table t1, and the trunk # of the freelist need to be read (3 pages). And only those three # pages need to be journalled. But 13 pages need to be written: # page1, the root page of table t1, and an 11 page overflow chain. # do_test pageropt-4.1 { db close sqlite3 db test.db pagercount_sql { INSERT INTO t1 VALUES(randomblob(11300)) } } {3 13 3} # Now we delete that big entries starting from a cold cache and an # empty freelist. The first 10 of the 11 pages overflow chain have # to be read, together with page1 and the root of the t1 table. 12 # reads total. But only page1, the t1 root, and the trunk of the # freelist need to be journalled and written back. # do_test pageropt-4.2 { db close sqlite3 db test.db pagercount_sql { DELETE FROM t1 } } {12 3 3} sqlite3_soft_heap_limit $cmdlinearg(soft-heap-limit) catch {db2 close} finish_test