Add comment to speculate when setting journal_mode=OFF on VACUUM does not

help performance.  No changes to code. (CVS 5071)

FossilOrigin-Name: 9c8b4babb2222a5e0c2ecf7a116b7df90084c81d

diff --git a/manifest b/manifest
index f26fd0202a9e6321c17cacd0e6010947c97ad200..6271f7af8307469afe5e9ecf88807e8e9c613542 100644 (file)
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Improved\soption\shandling\sin\sspeedtest8.c.\s\sAdded\s-quiet\sand\s-priority\soptions.\s\sAdded\sreporting\sof\stotal\suser\sand\ssystem\stime.\s(CVS\s5070)
-D 2008-04-30T15:55:34
+C Add\scomment\sto\sspeculate\swhen\ssetting\sjournal_mode=OFF\son\sVACUUM\sdoes\snot\nhelp\sperformance.\s\sNo\schanges\sto\scode.\s(CVS\s5071)
+D 2008-04-30T16:38:23
 F Makefile.arm-wince-mingw32ce-gcc ac5f7b2cef0cd850d6f755ba6ee4ab961b1fadf7
 F Makefile.in 25b3282a4ac39388632c2fb0e044ff494d490952
 F Makefile.linux-gcc d53183f4aa6a9192d249731c90dbdffbd2c68654
@@ -168,7 +168,7 @@ F src/trigger.c 9bd3b6fa0beff4a02d262c96466f752ec15a7fc3
 F src/update.c 2d7143b9014e955509cc4f323f9a9584fb898f34
 F src/utf.c 8c94fa10efc78c2568d08d436acc59df4df7191b
 F src/util.c a3907b05dcc3720a6d71bb39e61d67b0d994b51f
-F src/vacuum.c 3524411bfb58aac0d87eadd3e5b7cd532772af30
+F src/vacuum.c c3b2b70677f874102b8753bf494c232e777f3998
 F src/vdbe.c 26964ba7ed76d2a1c52747d601aaf2dc5b09b651
 F src/vdbe.h bfd84bda447f39cb599302c7ec85067dae20453c
 F src/vdbeInt.h 05316345da487b0cf540482576f9ae3337d133cd
@@ -633,7 +633,7 @@ F www/tclsqlite.tcl 8be95ee6dba05eabcd27a9d91331c803f2ce2130
 F www/vdbe.tcl 87a31ace769f20d3627a64fa1fade7fed47b90d0
 F www/version3.tcl 890248cf7b70e60c383b0e84d77d5132b3ead42b
 F www/whentouse.tcl fc46eae081251c3c181bd79c5faef8195d7991a5
-P fc0ca647bd1c7c953bb0f3eb7d3471572fd18c34
-R 8bd12bf8a3eaadb4e117c1f015393938
-U shane
-Z 09702a98c8183287a6fdc49d86797b33
+P aa59974ec15508d69c5b65ab89ec7bc32690018c
+R 75f14acd3f2bae6b9a939b5711d86e5b
+U drh
+Z 924c040e6c27c40e097c580fa3feeda2

diff --git a/manifest.uuid b/manifest.uuid
index 49e5a1914d680a6657bd56fbeb3ac1affa78b910..340a72eb2e9cdc2ec4b4ea194ba4466fce1de481 100644 (file)
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-aa59974ec15508d69c5b65ab89ec7bc32690018c
\ No newline at end of file
+9c8b4babb2222a5e0c2ecf7a116b7df90084c81d
\ No newline at end of file

diff --git a/src/vacuum.c b/src/vacuum.c
index 2bfd7aea9b6da5631d75a948a8aaa90e94b9a7e6..469c314d68216711c8a2ba9ba7ff6eae54946192 100644 (file)
--- a/src/vacuum.c
+++ b/src/vacuum.c
@@ -14,7 +14,7 @@
 ** Most of the code in this file may be omitted by defining the
 ** SQLITE_OMIT_VACUUM macro.
 **
-** $Id: vacuum.c,v 1.77 2008/03/20 11:04:21 danielk1977 Exp $
+** $Id: vacuum.c,v 1.78 2008/04/30 16:38:23 drh Exp $
 */
 #include "sqliteInt.h"
 #include "vdbeInt.h"
@@ -106,6 +106,12 @@ int sqlite3RunVacuum(char **pzErrMsg, sqlite3 *db){
   ** sqlite3BtreeCopyFile() is called.
   **
   ** An optimisation would be to use a non-journaled pager.
+  ** (Later:) I tried setting "PRAGMA vacuum_db.journal_mode=OFF" but
+  ** that actually made the VACUUM run slower.  Very little journalling
+  ** actually occurs when doing a vacuum since the vacuum_db is initially
+  ** empty.  Only the journal header is written.  Apparently it takes more
+  ** time to parse and run the PRAGMA to turn journalling off than it does
+  ** to write the journal header file.
   */
   zSql = "ATTACH '' AS vacuum_db;";
   rc = execSql(db, zSql);