Add the experimental SQLITE_DEFAULT_INDEX_SHAPE=1 compile-time option that
makes a much more pessimistic guess at the effectiveness of unanalyzed
indices.
FossilOrigin-Name: d8daaba7dae53c76858ff7d7de695af4763d9b1f
diff --git a/manifest b/manifest
index 15dc352..6135330 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Simplify\sbranch\scoverage\stesting\sby\sinterchanging\sthe\sorder\sof\stwo\stests\nin\sthe\swhereLoopInsert()\sfunction.
-D 2013-09-02T20:22:18.651
+C Add\sthe\sexperimental\sSQLITE_DEFAULT_INDEX_SHAPE=1\scompile-time\soption\sthat\nmakes\sa\smuch\smore\spessimistic\sguess\sat\sthe\seffectiveness\sof\sunanalyzed\nindices.
+D 2013-09-02T23:40:47.395
F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
F Makefile.in 5e41da95d92656a5004b03d3576e8b226858a28e
F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -166,7 +166,7 @@
F src/btree.c b9b57df546df2636294bfb21a986f5707b417df2
F src/btree.h bfe0e8c5759b4ec77b0d18390064a6ef3cdffaaf
F src/btreeInt.h 51cf220a9b9223354770883e93a859dc377aa27f
-F src/build.c f63e8929c7f89c0074fbc74929bc946ea117b2f8
+F src/build.c ec867822b389c3a4b7c4e33ad67448447b051f0c
F src/callback.c d7e46f40c3cf53c43550b7da7a1d0479910b62cc
F src/complete.c dc1d136c0feee03c2f7550bafc0d29075e36deac
F src/ctime.c ea4b7f3623a0fcb1146e7f245d7410033e86859c
@@ -1109,7 +1109,10 @@
F tool/warnings.sh fbc018d67fd7395f440c28f33ef0f94420226381
F tool/wherecosttest.c f407dc4c79786982a475261866a161cd007947ae
F tool/win/sqlite.vsix 97894c2790eda7b5bce3cc79cb2a8ec2fde9b3ac
-P 0a702c4b4c35fdbcb62e3ab88b9e57d7ea0052a8
-R 5255609fa5f702769f786eafe83d1965
+P f7079b5365dd6cd8324a4fb23605e81476122ed6
+R c46c3491c07bd978d38973714a975590
+T *branch * index-shape-1
+T *sym-index-shape-1 *
+T -sym-trunk *
U drh
-Z 3ad66b5373e173075a1fd9a0798ca8c7
+Z 86c8463cb0873ec75b5b5ad032212670
diff --git a/manifest.uuid b/manifest.uuid
index 59f020c..12cc91f 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-f7079b5365dd6cd8324a4fb23605e81476122ed6
\ No newline at end of file
+d8daaba7dae53c76858ff7d7de695af4763d9b1f
\ No newline at end of file
diff --git a/src/build.c b/src/build.c
index 491ca28..67360f6 100644
--- a/src/build.c
+++ b/src/build.c
@@ -2956,6 +2956,8 @@
tRowcnt *a = pIdx->aiRowEst;
int i;
tRowcnt n;
+
+#if !defined(SQLITE_DEFAULT_INDEX_SHAPE) || SQLITE_DEFAULT_INDEX_SHAPE==0
assert( a!=0 );
a[0] = pIdx->pTable->nRowEst;
if( a[0]<10 ) a[0] = 10;
@@ -2967,6 +2969,23 @@
if( pIdx->onError!=OE_None ){
a[pIdx->nColumn] = 1;
}
+#else /* if SQLITE_DEFAULT_INDEX_SHAPE==1 */
+ tRowcnt x = 1, nMax = pIdx->pTable->nRowEst;
+ int iLog;
+ int isUnique = pIdx->onError!=OE_None;
+ assert( a!=0 );
+ a[0] = nMax;
+ n = isUnique ? 1 : 10;
+ for(iLog=1; n<nMax; iLog++, n<<=1){}
+ i = pIdx->nColumn;
+ x <<= iLog/i;
+ //if( x>10 ) x = 10;
+ a[i] = n = isUnique ? 1 : 10;
+ while( i>1 ){
+ n *= x;
+ a[--i] = n;
+ }
+#endif
}
/*