diff options
Diffstat (limited to 'src/build.c')
| -rw-r--r-- | src/build.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/src/build.c b/src/build.c index a5931954a..c32195f65 100644 --- a/src/build.c +++ b/src/build.c @@ -3434,10 +3434,11 @@ void sqlite3DefaultRowEst(Index *pIdx){ int i; /* Set the first entry (number of rows in the index) to the estimated - ** number of rows in the table. Or 10, if the estimated number of rows - ** in the table is less than that. */ + ** number of rows in the table, or half the number of rows in the table + ** for a partial index. But do not let the estimate drop below 10. */ a[0] = pIdx->pTable->nRowLogEst; - if( a[0]<33 ) a[0] = 33; assert( 33==sqlite3LogEst(10) ); + if( pIdx->pPartIdxWhere!=0 ) a[0] -= 10; assert( 10==sqlite3LogEst(2) ); + if( a[0]<33 ) a[0] = 33; assert( 33==sqlite3LogEst(10) ); /* Estimate that a[1] is 10, a[2] is 9, a[3] is 8, a[4] is 7, a[5] is ** 6 and each subsequent value (if any) is 5. */ |