Skip to content

Fix COUNT(DISTINCT ...) collision for multi-column comma values #3781

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Closed
chiliec wants to merge 1 commit into from
Closed

Fix COUNT(DISTINCT ...) collision for multi-column comma values #3781

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
15 changes: 15 additions & 0 deletions sql/expression/function/aggregation/count_test.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -137,6 +137,21 @@ func TestCountDistinctEvalString(t *testing.T) {
require.Equal(int64(2), evalBuffer(t, b))
}

func TestCountDistinctEvalMultiColumn(t *testing.T) {
require := require.New(t)
ctx := sql.NewEmptyContext()

c := NewCountDistinct(
expression.NewGetField(0, types.Text, "", true),
expression.NewGetField(1, types.Text, "", true),
)
b, _ := c.NewBuffer(ctx)

require.NoError(b.Update(ctx, sql.NewRow("a,", "b")))
require.NoError(b.Update(ctx, sql.NewRow("a", ",b")))
require.Equal(int64(2), evalBuffer(t, b))
}

func TestCountDistinctEvalExtendedType(t *testing.T) {
require := require.New(t)
ctx := sql.NewEmptyContext()
Expand Down
15 changes: 5 additions & 10 deletions sql/expression/function/aggregation/unary_agg_buffers.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -486,7 +486,7 @@ func (c *countDistinctBuffer) Update(ctx *sql.Context, row sql.Row) error {
}
}

var str string
hash := xxhash.New()
for _, val := range value.(sql.Row) {
// skip nil values
if val == nil {
Expand All @@ -500,16 +500,11 @@ func (c *countDistinctBuffer) Update(ctx *sql.Context, row sql.Row) error {
if !ok {
return fmt.Errorf("count distinct unable to hash value: %s", err)
}
str += vv + ","
}

hash := xxhash.New()
_, err := hash.WriteString(str)
if err != nil {
return err
if _, err = fmt.Fprintf(hash, "%d:%s", len(vv), vv); err != nil {
return err
}
}
h := hash.Sum64()
c.seen[h] = struct{}{}
c.seen[hash.Sum64()] = struct{}{}

return nil
}
Expand Down
Loading