diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/where.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/src/where.c b/src/where.c index 0cda03f45..cdcaa98c0 100644 --- a/src/where.c +++ b/src/where.c @@ -2520,7 +2520,8 @@ range_est_fallback: ** an equality constraint x=VALUE and where that VALUE occurs in ** the histogram data. This only works when x is the left-most ** column of an index and sqlite_stat2 histogram data is available -** for that index. +** for that index. When pExpr==NULL that means the constraint is +** "x IS NULL" instead of "x=VALUE". ** ** Write the estimated row count into *pnRow and return SQLITE_OK. ** If unable to make an estimate, leave *pnRow unchanged and return |