SQLite

Check-in [b739189204]
Login

Many hyperlinks are disabled.
Use anonymous login to enable hyperlinks.

Overview
Comment:Change the way overflow pages are allocated from the free-list to increase the chance that they are a contiguous block. Much more can still be done. (CVS 4023)
Downloads: Tarball | ZIP archive
Timelines: family | ancestors | descendants | both | trunk
Files: files | file ages | folders
SHA1: b7391892041eb72b0ebcbb7a9a6721ae3482dd80
User & Date: danielk1977 2007-05-17 18:28:11.000
Context
2007-05-19
06:48
Add a few extra words to the sqlite3_finalize() documentation. (CVS 4024) (check-in: 315dc71b92 user: danielk1977 tags: trunk)
2007-05-17
18:28
Change the way overflow pages are allocated from the free-list to increase the chance that they are a contiguous block. Much more can still be done. (CVS 4023) (check-in: b739189204 user: danielk1977 tags: trunk)
16:38
Bring the autoconf based build system up to date with the recent changes. #2366, #2367 and #2368. (CVS 4022) (check-in: ae644bc7aa user: danielk1977 tags: trunk)
Changes
Side-by-Side Diff Ignore Whitespace Patch
Changes to src/btree.c. 
1
2
3
4
5
6
7
8
9
10
11
12

13
14
15
16
17
18
19

1
2
3
4
5
6
7
8
9
10
11

12
13
14
15
16
17
18
19












-
+








/*
** 2004 April 6
**
** 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.
**
*************************************************************************
** $Id: btree.c,v 1.382 2007/05/16 17:28:43 danielk1977 Exp $
** $Id: btree.c,v 1.383 2007/05/17 18:28:11 danielk1977 Exp $
**
** This file implements a external (disk-based) database using BTrees.
** See the header comment on "btreeInt.h" for additional information.
** Including a description of file format and an overview of operation.
*/
#include "btreeInt.h"
︙
3839
3840
3841
3842
3843
3844
3845

3846
3847










3848
3849

3850
3851
3852
3853
3854
3855
3856

3839
3840
3841
3842
3843
3844
3845
3846
3847
3848
3849
3850
3851
3852
3853
3854
3855
3856
3857
3858
3859

3860
3861
3862
3863
3864
3865
3866
3867








+


+
+
+
+
+
+
+
+
+
+

-
+








  *pnSize = info.nSize;
  spaceLeft = info.nLocal;
  pPayload = &pCell[nHeader];
  pPrior = &pCell[info.iOverflow];

  while( nPayload>0 ){
    if( spaceLeft==0 ){
      int isExact = 0;
#ifndef SQLITE_OMIT_AUTOVACUUM
      Pgno pgnoPtrmap = pgnoOvfl; /* Overflow page pointer-map entry page */
      if( pBt->autoVacuum ){
        do{
          pgnoOvfl++;
        } while( 
          PTRMAP_ISPAGE(pBt, pgnoOvfl) || pgnoOvfl==PENDING_BYTE_PAGE(pBt) 
        );
        if( pgnoOvfl>1 ){
          /* isExact = 1; */
        }
      }
#endif
      rc = allocateBtreePage(pBt, &pOvfl, &pgnoOvfl, pgnoOvfl, 0);
      rc = allocateBtreePage(pBt, &pOvfl, &pgnoOvfl, pgnoOvfl, isExact);
#ifndef SQLITE_OMIT_AUTOVACUUM
      /* If the database supports auto-vacuum, and the second or subsequent
      ** overflow page is being allocated, add an entry to the pointer-map
      ** for that page now. The entry for the first overflow page will be
      ** added later, by the insertCell() routine.
      */
      if( pBt->autoVacuum && pgnoPtrmap!=0 && rc==SQLITE_OK ){
︙
Changes to test/speed3.test.
︙
8
9
10
11
12
13
14
15

16
17
18
19
20
21
22

8
9
10
11
12
13
14

15
16
17
18
19
20
21
22








-
+








#    May you share freely, never taking more than you give.
#
#*************************************************************************
# This file implements regression tests for SQLite library. The 
# focus of this script is testing that the overflow-page related
# enhancements added after version 3.3.17 speed things up.
#
# $Id: speed3.test,v 1.1 2007/05/17 14:45:13 danielk1977 Exp $
# $Id: speed3.test,v 1.2 2007/05/17 18:28:11 danielk1977 Exp $
#

#---------------------------------------------------------------------
# Test plan:
#
# If auto-vacuum is enabled for the database, the following cases
# should show performance improvement with respect to 3.3.17.
︙
92
93
94
95
96
97
98












99
100
101
102
103
104
105

92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117








+
+
+
+
+
+
+
+
+
+
+
+








  array set stats1 [btree_pager_stats [btree_from_db db]]
  array set stats2 [btree_pager_stats [btree_from_db db 2]]
# puts "1: [array get stats1]"
# puts "2: [array get stats2]"
  puts "Incrvacuum: Read $stats1(read), wrote $stats1(write)"
  puts "Normal    : Read $stats2(read), wrote $stats2(write)"
}

proc overflow_report {db} {
  set bt [btree_from_db db]
  set csr [btree_cursor $bt 3 0]

  for {btree_first $csr} {![btree_eof $csr]} {btree_next $csr} {
    puts "[btree_ovfl_info $bt $csr]"
  }

  btree_close_cursor $csr
  
}

proc reset_db {} {
  db close
  sqlite3 db test.db
  db eval { 
    PRAGMA main.cache_size = 200000;
    PRAGMA main.auto_vacuum = 'incremental';
︙
142
143
144
145
146
147
148

149
150
151
152
153
154
155
156
157

158

159
160
161
162
163
164
165

154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169

170
171
172
173
174
175
176
177
178
179








+








-
+

+








    PRAGMA aux.auto_vacuum;
  }
} {2 0}

# Delete all content in a table, one row at a time.
#
#io_log db
#overflow_report db
reset_db
speed_trial speed3-1.incrvacuum $::NROW row {DELETE FROM main.t1 WHERE 1}
speed_trial speed3-1.normal     $::NROW row {DELETE FROM aux.t1 WHERE 1}
io_log db

# Select the "C" column (located at the far end of the overflow 
# chain) from each table row.
#
db eval {PRAGMA incremental_vacuum(500000)}
#db eval {PRAGMA incremental_vacuum(500000)}
populate_t1 db
#overflow_report db
reset_db
speed_trial speed3-2.incrvacuum $::NROW row {SELECT c FROM main.t1}
speed_trial speed3-2.normal     $::NROW row {SELECT c FROM aux.t1}
io_log db

finish_test