Improved comments on virtual table query planning. Added many new

WHERETRACE() macros.

FossilOrigin-Name: 4c89c2534abcf67bc486d5a900a84a6c4f59537e

diff --git a/manifest b/manifest
index bb6f77ee42db90fcd8f0d78b188ad52acfbf7334..25c4175d4afe547c3c0d1f9a6c5d0b1ff14ada79 100644 (file)
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C In\smemjournal.c,\sreuse\sthe\ssame\ssqlite3_file\sobject\sfor\sboth\sthe\sin-memory\nphase\sand\sthe\son-disk\sphase.
-D 2016-03-08T17:59:19.784
+C Improved\scomments\son\svirtual\stable\squery\splanning.\s\sAdded\smany\snew\nWHERETRACE()\smacros.
+D 2016-03-08T23:18:51.182
 F Makefile.in f53429fb2f313c099283659d0df6f20f932c861f
 F Makefile.linux-gcc 7bc79876b875010e8c8f9502eb935ca92aa3c434
 F Makefile.msc df0bf9ff7f8b3f4dd9fb4cc43f92fe58f6ec5c66
@@ -429,7 +429,7 @@ F src/vxworks.h d2988f4e5a61a4dfe82c6524dd3d6e4f2ce3cdb9
 F src/wal.c 10deb6b43887662691e5f53d10b3c171c401169b
 F src/wal.h 2f7c831cf3b071fa548bf2d5cac640846a7ff19c
 F src/walker.c 0f142b5bd3ed2041fc52d773880748b212e63354
-F src/where.c dff52f7f0842430f80a7017c7859124685b08453
+F src/where.c a3f6db088f335a9217fe53d976f9441610061a2f
 F src/whereInt.h 93297d56edd137b7ea004490690fb6e2ce028a34
 F src/wherecode.c 863aedf086131743763c1960637fde904eadc442
 F src/whereexpr.c fb87944b1254234e5bba671aaf6dee476241506a
@@ -1455,8 +1455,7 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P f6d3156ba9af1da517dd77c1df03fa7869888463 d99ac4154812065eef26c298de52954d7ee0bd75
-R bec56382cb26d93b90f8b590f852c457
-T +closed d99ac4154812065eef26c298de52954d7ee0bd75
+P e7fbbdc25c0991d4e58d78a5fcb7386e1aa7f3af
+R 624279792742522c1a4793f09c7ca2f6
 U drh
-Z 55dc3dcac976fd228dc3d62385f9ab1a
+Z ab3adc4bc8a1b11824c36206a5455ed4

diff --git a/manifest.uuid b/manifest.uuid
index 45d67c3642b2d0c765af765bdd5f3d8c2e0d5463..572a4db2fbc5e651c84774e85236fb23cef8c020 100644 (file)
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-e7fbbdc25c0991d4e58d78a5fcb7386e1aa7f3af
\ No newline at end of file
+4c89c2534abcf67bc486d5a900a84a6c4f59537e
\ No newline at end of file

diff --git a/src/where.c b/src/where.c
index 2d7272a74276394249822d4b486770d59d805a83..364bfca3c501c8bb8bbaecb5e82304dbd8c4166e 100644 (file)
--- a/src/where.c
+++ b/src/where.c
@@ -2892,6 +2892,9 @@ static int whereLoopAddVirtualOne(
     sqlite3_free(pNew->u.vtab.idxStr);
     pNew->u.vtab.needFree = 0;
   }
+  WHERETRACE(0xffff, ("  bIn=%d prereqIn=%04llx prereqOut=%04llx\n",
+                      *pbIn, (sqlite3_uint64)mPrereq,
+                      (sqlite3_uint64)(pNew->prereq & ~mPrereq)));
 
   return SQLITE_OK;
 }
@@ -2958,15 +2961,15 @@ static int whereLoopAddVirtual(
   }
 
   /* First call xBestIndex() with all constraints usable. */
+  WHERETRACE(0x40, ("  VirtualOne: all usable\n"));
   rc = whereLoopAddVirtualOne(pBuilder, mPrereq, ALLBITS, 0, p, &bIn);
-  mBest = pNew->prereq & ~mPrereq;
 
   /* If the call to xBestIndex() with all terms enabled produced a plan
-  ** that does not require any source tables, there is no point in making
-  ** any further calls - if the xBestIndex() method is sane they will all
-  ** return the same plan anyway.
-  */
-  if( mBest ){
+  ** that does not require any source tables (IOW: a plan with mBest==0),
+  ** then there is no point in making any further calls to xBestIndex() 
+  ** since they will all return the same result (if the xBestIndex()
+  ** implementation is sane). */
+  if( rc==SQLITE_OK && (mBest = (pNew->prereq & ~mPrereq))!=0 ){
     int seenZero = 0;             /* True if a plan with no prereqs seen */
     int seenZeroNoIN = 0;         /* Plan with no prereqs and no IN(...) seen */
     Bitmask mPrev = 0;
@@ -2974,7 +2977,8 @@ static int whereLoopAddVirtual(
 
     /* If the plan produced by the earlier call uses an IN(...) term, call
     ** xBestIndex again, this time with IN(...) terms disabled. */
-    if( rc==SQLITE_OK && bIn ){
+    if( bIn ){
+      WHERETRACE(0x40, ("  VirtualOne: all usable w/o IN\n"));
       rc = whereLoopAddVirtualOne(pBuilder, mPrereq, ALLBITS, WO_IN, p, &bIn);
       assert( bIn==0 );
       mBestNoIn = pNew->prereq & ~mPrereq;
@@ -2999,6 +3003,8 @@ static int whereLoopAddVirtual(
       mPrev = mNext;
       if( mNext==ALLBITS ) break;
       if( mNext==mBest || mNext==mBestNoIn ) continue;
+      WHERETRACE(0x40, ("  VirtualOne: mPrev=%04llx mNext=%04llx\n",
+                       (sqlite3_uint64)mPrev, (sqlite3_uint64)mNext));
       rc = whereLoopAddVirtualOne(pBuilder, mPrereq, mNext|mPrereq, 0, p, &bIn);
       if( pNew->prereq==mPrereq ){
         seenZero = 1;
@@ -3010,6 +3016,7 @@ static int whereLoopAddVirtual(
     ** that requires no source tables at all (i.e. one guaranteed to be
     ** usable), make a call here with all source tables disabled */
     if( rc==SQLITE_OK && seenZero==0 ){
+      WHERETRACE(0x40, ("  VirtualOne: all disabled\n"));
       rc = whereLoopAddVirtualOne(pBuilder, mPrereq, mPrereq, 0, p, &bIn);
       if( bIn==0 ) seenZeroNoIN = 1;
     }
@@ -3018,6 +3025,7 @@ static int whereLoopAddVirtual(
     ** that requires no source tables at all and does not use an IN(...)
     ** operator, make a final call to obtain one here.  */
     if( rc==SQLITE_OK && seenZeroNoIN==0 ){
+      WHERETRACE(0x40, ("  VirtualOne: all disabled and w/o IN\n"));
       rc = whereLoopAddVirtualOne(pBuilder, mPrereq, mPrereq, WO_IN, p, &bIn);
     }
   }