diff --git a/ext/stats/percentile.go b/ext/stats/percentile.go
index dafd339..c60ca22 100644
--- a/ext/stats/percentile.go
+++ b/ext/stats/percentile.go
@@ -28,11 +28,13 @@ type percentile struct {
 }
 
 func (q *percentile) Step(ctx sqlite3.Context, arg ...sqlite3.Value) {
-	if a := arg[0]; a.NumericType() != sqlite3.NULL {
-		q.nums = append(q.nums, a.Float())
+	a := arg[0]
+	f := a.Float()
+	if f != 0.0 || a.NumericType() != sqlite3.NULL {
+		q.nums = append(q.nums, f)
 	}
-	if q.kind != median {
-		q.arg1 = append(q.arg1[:0], arg[1].RawText()...)
+	if q.kind != median && q.arg1 == nil {
+		q.arg1 = append(q.arg1, arg[1].RawText()...)
 	}
 }
 
diff --git a/ext/stats/stats.go b/ext/stats/stats.go
index f16423d..cddbffa 100644
--- a/ext/stats/stats.go
+++ b/ext/stats/stats.go
@@ -121,14 +121,18 @@ func (fn *variance) Value(ctx sqlite3.Context) {
 }
 
 func (fn *variance) Step(ctx sqlite3.Context, arg ...sqlite3.Value) {
-	if a := arg[0]; a.NumericType() != sqlite3.NULL {
-		fn.enqueue(a.Float())
+	a := arg[0]
+	f := a.Float()
+	if f != 0.0 || a.NumericType() != sqlite3.NULL {
+		fn.enqueue(f)
 	}
 }
 
 func (fn *variance) Inverse(ctx sqlite3.Context, arg ...sqlite3.Value) {
-	if a := arg[0]; a.NumericType() != sqlite3.NULL {
-		fn.dequeue(a.Float())
+	a := arg[0]
+	f := a.Float()
+	if f != 0.0 || a.NumericType() != sqlite3.NULL {
+		fn.dequeue(f)
 	}
 }
 
@@ -178,14 +182,22 @@ func (fn *covariance) Value(ctx sqlite3.Context) {
 
 func (fn *covariance) Step(ctx sqlite3.Context, arg ...sqlite3.Value) {
 	b, a := arg[1], arg[0] // avoid a bounds check
-	if a.NumericType() != sqlite3.NULL && b.NumericType() != sqlite3.NULL {
-		fn.enqueue(a.Float(), b.Float())
+	fa := a.Float()
+	fb := b.Float()
+	if true &&
+		(fa != 0.0 || a.NumericType() != sqlite3.NULL) &&
+		(fb != 0.0 || b.NumericType() != sqlite3.NULL) {
+		fn.enqueue(fa, fb)
 	}
 }
 
 func (fn *covariance) Inverse(ctx sqlite3.Context, arg ...sqlite3.Value) {
 	b, a := arg[1], arg[0] // avoid a bounds check
-	if a.NumericType() != sqlite3.NULL && b.NumericType() != sqlite3.NULL {
-		fn.dequeue(a.Float(), b.Float())
+	fa := a.Float()
+	fb := b.Float()
+	if true &&
+		(fa != 0.0 || a.NumericType() != sqlite3.NULL) &&
+		(fb != 0.0 || b.NumericType() != sqlite3.NULL) {
+		fn.dequeue(fa, fb)
 	}
 }
diff --git a/sqlite3/bind.c b/sqlite3/bind.c
index 254c232..bce1177 100644
--- a/sqlite3/bind.c
+++ b/sqlite3/bind.c
@@ -2,12 +2,12 @@
 
 #include "sqlite3.h"
 
-int sqlite3_bind_text_go(sqlite3_stmt* stmt, int i, const char* zData,
+int sqlite3_bind_text_go(sqlite3_stmt *stmt, int i, const char *zData,
                          sqlite3_uint64 nData) {
   return sqlite3_bind_text64(stmt, i, zData, nData, &sqlite3_free, SQLITE_UTF8);
 }
 
-int sqlite3_bind_blob_go(sqlite3_stmt* stmt, int i, const char* zData,
+int sqlite3_bind_blob_go(sqlite3_stmt *stmt, int i, const char *zData,
                          sqlite3_uint64 nData) {
   return sqlite3_bind_blob64(stmt, i, zData, nData, &sqlite3_free);
 }
\ No newline at end of file
diff --git a/sqlite3/result.c b/sqlite3/result.c
index 6e79772..b59b26a 100644
--- a/sqlite3/result.c
+++ b/sqlite3/result.c
@@ -1,13 +1,14 @@
+#include <math.h>
 #include <stdlib.h>
 
 #include "sqlite3.h"
 
-void sqlite3_result_text_go(sqlite3_context* ctx, const char* zData,
+void sqlite3_result_text_go(sqlite3_context *ctx, const char *zData,
                             sqlite3_uint64 nData) {
   sqlite3_result_text64(ctx, zData, nData, &sqlite3_free, SQLITE_UTF8);
 }
 
-void sqlite3_result_blob_go(sqlite3_context* ctx, const void* zData,
+void sqlite3_result_blob_go(sqlite3_context *ctx, const void *zData,
                             sqlite3_uint64 nData) {
   sqlite3_result_blob64(ctx, zData, nData, &sqlite3_free);
 }
\ No newline at end of file
diff --git a/vfs/memdb/api.go b/vfs/memdb/api.go
index 8434889..eb12eba 100644
--- a/vfs/memdb/api.go
+++ b/vfs/memdb/api.go
@@ -43,7 +43,8 @@ func Create(name string, data []byte) {
 	}
 
 	// Convert data from WAL/2 to rollback journal.
-	if len(data) >= 20 && (data[18] == 2 && data[19] == 2 ||
+	if len(data) >= 20 && (false ||
+		data[18] == 2 && data[19] == 2 ||
 		data[18] == 3 && data[19] == 3) {
 		data[18] = 1
 		data[19] = 1