From e965728f2218402981d659dcd27c91f9c02d373a Mon Sep 17 00:00:00 2001
From: taniabogatsch <44262898+taniabogatsch@users.noreply.github.com>
Date: Tue, 10 Sep 2024 12:42:10 +0200
Subject: [PATCH 1/8] started working on profiling

---
 appender.go       |  4 +--
 errors.go         | 12 +++++----
 errors_test.go    |  8 +++---
 profiling.go      | 67 +++++++++++++++++++++++++++++++++++++++++++++++
 profiling_test.go | 46 ++++++++++++++++++++++++++++++++
 5 files changed, 126 insertions(+), 11 deletions(-)
 create mode 100644 profiling.go
 create mode 100644 profiling_test.go

diff --git a/appender.go b/appender.go
index 31396201..fa611903 100644
--- a/appender.go
+++ b/appender.go
@@ -34,10 +34,10 @@ type Appender struct {
 func NewAppenderFromConn(driverConn driver.Conn, schema, table string) (*Appender, error) {
 	con, ok := driverConn.(*conn)
 	if !ok {
-		return nil, getError(errAppenderInvalidCon, nil)
+		return nil, getError(errInvalidCon, nil)
 	}
 	if con.closed {
-		return nil, getError(errAppenderClosedCon, nil)
+		return nil, getError(errClosedCon, nil)
 	}
 
 	var cSchema *C.char
diff --git a/errors.go b/errors.go
index 06112b04..77ff5c1f 100644
--- a/errors.go
+++ b/errors.go
@@ -60,14 +60,14 @@ var (
 	errAPI        = errors.New("API error")
 	errVectorSize = errors.New("data chunks cannot exceed duckdb's internal vector size")
 
-	errParseDSN  = errors.New("could not parse DSN for database")
-	errOpen      = errors.New("could not open database")
-	errSetConfig = errors.New("could not set invalid or local option for global database config")
+	errParseDSN   = errors.New("could not parse DSN for database")
+	errOpen       = errors.New("could not open database")
+	errSetConfig  = errors.New("could not set invalid or local option for global database config")
+	errInvalidCon = errors.New("not a DuckDB driver connection")
+	errClosedCon  = errors.New("closed connection")
 
 	errUnsupportedMapKeyType = errors.New("MAP key type not supported")
 
-	errAppenderInvalidCon       = errors.New("could not create appender: not a DuckDB driver connection")
-	errAppenderClosedCon        = errors.New("could not create appender: appender creation on a closed connection")
 	errAppenderCreation         = errors.New("could not create appender")
 	errAppenderDoubleClose      = errors.New("could not close appender: already closed")
 	errAppenderAppendRow        = errors.New("could not append row")
@@ -75,6 +75,8 @@ var (
 	errAppenderClose            = errors.New("could not close appender")
 	errAppenderFlush            = errors.New("could not flush appender")
 
+	errProfilingInfoEmpty = errors.New("no profiling information available for this connection")
+
 	// Errors not covered in tests.
 	errConnect      = errors.New("could not connect to database")
 	errCreateConfig = errors.New("could not create config for database")
diff --git a/errors_test.go b/errors_test.go
index be1e8811..63467409 100644
--- a/errors_test.go
+++ b/errors_test.go
@@ -59,13 +59,13 @@ func TestErrNestedMap(t *testing.T) {
 func TestErrAppender(t *testing.T) {
 	t.Parallel()
 
-	t.Run(errAppenderInvalidCon.Error(), func(t *testing.T) {
+	t.Run(errInvalidCon.Error(), func(t *testing.T) {
 		var con driver.Conn
 		_, err := NewAppenderFromConn(con, "", "test")
-		testError(t, err, errAppenderInvalidCon.Error())
+		testError(t, err, errInvalidCon.Error())
 	})
 
-	t.Run(errAppenderClosedCon.Error(), func(t *testing.T) {
+	t.Run(errClosedCon.Error(), func(t *testing.T) {
 		c, err := NewConnector("", nil)
 		require.NoError(t, err)
 
@@ -74,7 +74,7 @@ func TestErrAppender(t *testing.T) {
 		require.NoError(t, con.Close())
 
 		_, err = NewAppenderFromConn(con, "", "test")
-		testError(t, err, errAppenderClosedCon.Error())
+		testError(t, err, errClosedCon.Error())
 		require.NoError(t, c.Close())
 	})
 
diff --git a/profiling.go b/profiling.go
new file mode 100644
index 00000000..4292a344
--- /dev/null
+++ b/profiling.go
@@ -0,0 +1,67 @@
+package duckdb
+
+/*
+#include <duckdb.h>
+*/
+import "C"
+import (
+	"unsafe"
+)
+
+type ProfilingInfo struct {
+	Metrics  map[string]string
+	Children []ProfilingInfo
+}
+
+func GetProfilingInfo(driverConn any) (ProfilingInfo, error) {
+	info := ProfilingInfo{}
+
+	con, ok := driverConn.(*conn)
+	if !ok {
+		return info, getError(errInvalidCon, nil)
+	}
+	if con.closed {
+		return info, getError(errClosedCon, nil)
+	}
+
+	duckdbInfo := C.duckdb_get_profiling_info(con.duckdbCon)
+	if duckdbInfo == nil {
+		return info, getError(errProfilingInfoEmpty, nil)
+	}
+
+	// Recursive tree traversal.
+	info.getMetrics(duckdbInfo)
+	return info, nil
+}
+
+func (info *ProfilingInfo) getMetrics(duckdbInfo C.duckdb_profiling_info) {
+	m := C.duckdb_profiling_info_get_metrics(duckdbInfo)
+	count := C.duckdb_get_map_size(m)
+
+	for i := C.idx_t(0); i < count; i++ {
+		key := C.duckdb_get_map_key(m, i)
+		value := C.duckdb_get_map_value(m, i)
+
+		cKey := C.duckdb_get_varchar(key)
+		cValue := C.duckdb_get_varchar(value)
+
+		keyStr := C.GoString(cKey)
+		valueStr := C.GoString(cValue)
+
+		info.Metrics[keyStr] = valueStr
+
+		C.duckdb_destroy_value(&key)
+		C.duckdb_destroy_value(&value)
+		C.duckdb_free(unsafe.Pointer(cKey))
+		C.duckdb_free(unsafe.Pointer(cValue))
+	}
+	C.duckdb_destroy_value(&m)
+
+	childCount := C.duckdb_profiling_info_get_child_count(duckdbInfo)
+	for i := C.idx_t(0); i < childCount; i++ {
+		duckdbChildInfo := C.duckdb_profiling_info_get_child(duckdbInfo, i)
+		childInfo := ProfilingInfo{}
+		childInfo.getMetrics(duckdbChildInfo)
+		info.Children = append(info.Children, childInfo)
+	}
+}
diff --git a/profiling_test.go b/profiling_test.go
new file mode 100644
index 00000000..742f94df
--- /dev/null
+++ b/profiling_test.go
@@ -0,0 +1,46 @@
+package duckdb
+
+import (
+	"context"
+	"database/sql"
+	"fmt"
+	"github.com/stretchr/testify/require"
+	"testing"
+)
+
+func TestProfiling(t *testing.T) {
+	db, err := sql.Open("duckdb", "")
+	require.NoError(t, err)
+
+	con, err := db.Conn(context.Background())
+	require.NoError(t, err)
+
+	_, err = con.ExecContext(context.Background(), `PRAGMA enable_profiling = 'no_output'`)
+	require.NoError(t, err)
+
+	_, err = con.ExecContext(context.Background(), `PRAGMA profiling_mode = 'detailed'`)
+	require.NoError(t, err)
+
+	res, err := con.QueryContext(context.Background(), "SELECT range AS i FROM range(100) ORDER BY i")
+	require.NoError(t, err)
+
+	//var info ProfilingInfo
+	err = con.Raw(func(driverCon any) error {
+		info, errGetInfo := GetProfilingInfo(driverCon)
+		require.NoError(t, errGetInfo)
+		fmt.Println(info)
+		return nil
+	})
+
+	//info, err := GetProfilingInfo(con)
+	//require.NoError(t, err)
+
+	require.NoError(t, res.Close())
+	require.NoError(t, con.Close())
+	require.NoError(t, db.Close())
+
+	// Verify our metrics.
+	//require.NotEmpty(t, info.Metrics, "metrics must not be empty")
+	//require.NotEmpty(t, info.Children, "children must not be empty")
+	//fmt.Println(info)
+}

From bc5ba8daf0d80a1ebf0420c65032296f5f35c62b Mon Sep 17 00:00:00 2001
From: taniabogatsch <44262898+taniabogatsch@users.noreply.github.com>
Date: Tue, 10 Sep 2024 15:52:38 +0200
Subject: [PATCH 2/8] add profiling support

---
 errors_test.go    | 37 +++++++++++++++++++++++++++++++++++++
 profiling_test.go | 20 ++++++++++----------
 2 files changed, 47 insertions(+), 10 deletions(-)

diff --git a/errors_test.go b/errors_test.go
index 63467409..ac217408 100644
--- a/errors_test.go
+++ b/errors_test.go
@@ -302,6 +302,43 @@ func TestErrAPISetValue(t *testing.T) {
 	testError(t, err, errAPI.Error(), columnCountErrMsg)
 }
 
+func TestErrProfiling(t *testing.T) {
+	t.Parallel()
+
+	t.Run(errInvalidCon.Error(), func(t *testing.T) {
+		var con driver.Conn
+		_, err := GetProfilingInfo(con)
+		testError(t, err, errInvalidCon.Error())
+	})
+
+	t.Run(errClosedCon.Error(), func(t *testing.T) {
+		c, err := NewConnector("", nil)
+		require.NoError(t, err)
+
+		con, err := c.Connect(context.Background())
+		require.NoError(t, err)
+		require.NoError(t, con.Close())
+
+		_, err = GetProfilingInfo(con)
+		testError(t, err, errClosedCon.Error())
+		require.NoError(t, c.Close())
+	})
+
+	t.Run(errProfilingInfoEmpty.Error(), func(t *testing.T) {
+		c, err := NewConnector("", nil)
+		require.NoError(t, err)
+
+		con, err := c.Connect(context.Background())
+		require.NoError(t, err)
+
+		_, err = GetProfilingInfo(con)
+		testError(t, err, errProfilingInfoEmpty.Error())
+
+		require.NoError(t, con.Close())
+		require.NoError(t, c.Close())
+	})
+}
+
 func TestDuckDBErrors(t *testing.T) {
 	db := openDB(t)
 	defer db.Close()
diff --git a/profiling_test.go b/profiling_test.go
index 742f94df..7e6d0e00 100644
--- a/profiling_test.go
+++ b/profiling_test.go
@@ -9,6 +9,8 @@ import (
 )
 
 func TestProfiling(t *testing.T) {
+	t.Parallel()
+
 	db, err := sql.Open("duckdb", "")
 	require.NoError(t, err)
 
@@ -24,23 +26,21 @@ func TestProfiling(t *testing.T) {
 	res, err := con.QueryContext(context.Background(), "SELECT range AS i FROM range(100) ORDER BY i")
 	require.NoError(t, err)
 
-	//var info ProfilingInfo
+	var info ProfilingInfo
 	err = con.Raw(func(driverCon any) error {
-		info, errGetInfo := GetProfilingInfo(driverCon)
-		require.NoError(t, errGetInfo)
-		fmt.Println(info)
-		return nil
+		info, err = GetProfilingInfo(driverCon)
+		return err
 	})
-
-	//info, err := GetProfilingInfo(con)
-	//require.NoError(t, err)
+	require.NoError(t, err)
 
 	require.NoError(t, res.Close())
 	require.NoError(t, con.Close())
 	require.NoError(t, db.Close())
 
-	// Verify our metrics.
+	// Verify the metrics.
+	// TODO: currently failing due to C API bug.
+	fmt.Println(info) // Dummy print to use variable.
 	//require.NotEmpty(t, info.Metrics, "metrics must not be empty")
 	//require.NotEmpty(t, info.Children, "children must not be empty")
-	//fmt.Println(info)
+	//require.NotEmpty(t, info.Children[0].Metrics, "child metrics must not be empty")
 }

From 9b99a4b1dfe0131affe6d24cabcb396eb9d3cfd7 Mon Sep 17 00:00:00 2001
From: taniabogatsch <44262898+taniabogatsch@users.noreply.github.com>
Date: Tue, 10 Sep 2024 15:53:32 +0200
Subject: [PATCH 3/8] formatter

---
 profiling.go      | 1 +
 profiling_test.go | 9 +++++----
 2 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/profiling.go b/profiling.go
index 4292a344..c3eb1f00 100644
--- a/profiling.go
+++ b/profiling.go
@@ -4,6 +4,7 @@ package duckdb
 #include <duckdb.h>
 */
 import "C"
+
 import (
 	"unsafe"
 )
diff --git a/profiling_test.go b/profiling_test.go
index 7e6d0e00..c07c467c 100644
--- a/profiling_test.go
+++ b/profiling_test.go
@@ -4,8 +4,9 @@ import (
 	"context"
 	"database/sql"
 	"fmt"
-	"github.com/stretchr/testify/require"
 	"testing"
+
+	"github.com/stretchr/testify/require"
 )
 
 func TestProfiling(t *testing.T) {
@@ -40,7 +41,7 @@ func TestProfiling(t *testing.T) {
 	// Verify the metrics.
 	// TODO: currently failing due to C API bug.
 	fmt.Println(info) // Dummy print to use variable.
-	//require.NotEmpty(t, info.Metrics, "metrics must not be empty")
-	//require.NotEmpty(t, info.Children, "children must not be empty")
-	//require.NotEmpty(t, info.Children[0].Metrics, "child metrics must not be empty")
+	// require.NotEmpty(t, info.Metrics, "metrics must not be empty")
+	// require.NotEmpty(t, info.Children, "children must not be empty")
+	// require.NotEmpty(t, info.Children[0].Metrics, "child metrics must not be empty")
 }

From 6b761fdfac1c0366cb7198d3fcae670bb4113903 Mon Sep 17 00:00:00 2001
From: taniabogatsch <44262898+taniabogatsch@users.noreply.github.com>
Date: Wed, 11 Sep 2024 11:27:30 +0200
Subject: [PATCH 4/8] add profiling documentation

---
 README.md         | 36 ++++++++++++++++++++++++++++++++++++
 profiling.go      | 10 +++++++++-
 profiling_test.go |  5 ++++-
 3 files changed, 49 insertions(+), 2 deletions(-)

diff --git a/README.md b/README.md
index f459a07c..53f78a69 100644
--- a/README.md
+++ b/README.md
@@ -129,6 +129,42 @@ if err != nil {
 }
 ```
 
+## DuckDB Profiling API
+
+This section describes using the [DuckDB Profiling API](https://duckdb.org/docs/dev/profiling.html).
+DuckDB's profiling information is connection-local.
+The following example walks you through the necessary steps to obtain the `ProfilingInformation` type, which contains all available metrics.
+Please refer to the [DuckDB documentation](https://duckdb.org/docs/dev/profiling.html) on configuring and collecting specific metrics.
+
+- First, you need to obtain a connection.
+- Then, you enable profiling for the connection.
+- Now, for each subsequent query on this connection, DuckDB will collect profiling information.
+    - Optionally, you can turn off profiling at any point.
+- Next, you execute the query for which you want to obtain profiling information.
+- Finally, directly after executing the query, you use the underlying DuckDB connection to retrieve any available profiling information.
+
+For readability, we omit error handling in this example.
+```Go
+db, err := sql.Open("duckdb", "")
+con, err := db.Conn(context.Background())
+
+_, err = con.ExecContext(context.Background(), `PRAGMA enable_profiling = 'no_output'`)
+_, err = con.ExecContext(context.Background(), `PRAGMA profiling_mode = 'detailed'`)
+
+res, err := con.QueryContext(context.Background(), `SELECT 42`)
+
+var info ProfilingInfo
+err = con.Raw(func(driverCon any) error {
+    info, err = GetProfilingInfo(driverCon)
+    return err
+})
+err = res.Close()
+
+_, err = con.ExecContext(context.Background(), `PRAGMA disable_profiling`)
+err = con.Close()
+err = db.Close()
+```
+
 ## DuckDB Apache Arrow Interface
 
 If you want to use the [DuckDB Arrow Interface](https://duckdb.org/docs/api/c/api#arrow-interface), you can obtain a new `Arrow` by passing a DuckDB connection to `NewArrowFromConn()`.
diff --git a/profiling.go b/profiling.go
index c3eb1f00..cc4ec427 100644
--- a/profiling.go
+++ b/profiling.go
@@ -9,11 +9,19 @@ import (
 	"unsafe"
 )
 
+// ProfilingInfo is a recursive type containing metrics for each node in DuckDB's query plan.
+// There are two types of nodes: the QUERY_ROOT and OPERATOR nodes.
+// The QUERY_ROOT refers exclusively to the top-level node; its metrics are measured over the entire query.
+// The OPERATOR nodes refer to the individual operators in the query plan.
 type ProfilingInfo struct {
-	Metrics  map[string]string
+	// Metrics contains all key-value pairs of the current node.
+	// The key represents the name and corresponds to the measured value.
+	Metrics map[string]string
+	// Children contains all children of the node and their respective metrics.
 	Children []ProfilingInfo
 }
 
+// GetProfilingInfo obtains all available metrics set by the current connection.
 func GetProfilingInfo(driverConn any) (ProfilingInfo, error) {
 	info := ProfilingInfo{}
 
diff --git a/profiling_test.go b/profiling_test.go
index c07c467c..e345ec9d 100644
--- a/profiling_test.go
+++ b/profiling_test.go
@@ -24,7 +24,7 @@ func TestProfiling(t *testing.T) {
 	_, err = con.ExecContext(context.Background(), `PRAGMA profiling_mode = 'detailed'`)
 	require.NoError(t, err)
 
-	res, err := con.QueryContext(context.Background(), "SELECT range AS i FROM range(100) ORDER BY i")
+	res, err := con.QueryContext(context.Background(), `SELECT range AS i FROM range(100) ORDER BY i`)
 	require.NoError(t, err)
 
 	var info ProfilingInfo
@@ -34,6 +34,9 @@ func TestProfiling(t *testing.T) {
 	})
 	require.NoError(t, err)
 
+	_, err = con.ExecContext(context.Background(), `PRAGMA disable_profiling`)
+	require.NoError(t, err)
+
 	require.NoError(t, res.Close())
 	require.NoError(t, con.Close())
 	require.NoError(t, db.Close())

From 86c4e331902c501b093dc5d09810ef396aeb2d38 Mon Sep 17 00:00:00 2001
From: taniabogatsch <44262898+taniabogatsch@users.noreply.github.com>
Date: Wed, 11 Sep 2024 15:44:30 +0200
Subject: [PATCH 5/8] nit

---
 profiling_test.go | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/profiling_test.go b/profiling_test.go
index e345ec9d..92ff840a 100644
--- a/profiling_test.go
+++ b/profiling_test.go
@@ -28,8 +28,8 @@ func TestProfiling(t *testing.T) {
 	require.NoError(t, err)
 
 	var info ProfilingInfo
-	err = con.Raw(func(driverCon any) error {
-		info, err = GetProfilingInfo(driverCon)
+	err = con.Raw(func(driverConn any) error {
+		info, err = GetProfilingInfo(driverConn)
 		return err
 	})
 	require.NoError(t, err)

From db3245d144a228f6399ca2fb58772752b56b9b22 Mon Sep 17 00:00:00 2001
From: taniabogatsch <44262898+taniabogatsch@users.noreply.github.com>
Date: Tue, 24 Sep 2024 13:51:16 +0200
Subject: [PATCH 6/8] small fixes after moving to latest duckdb

---
 errors_test.go     | 37 -------------------------------------
 profiling.go       | 31 ++++++++++++++-----------------
 profiling_test.go  | 32 +++++++++++++++++---------------
 scalar_udf_test.go |  2 +-
 4 files changed, 32 insertions(+), 70 deletions(-)

diff --git a/errors_test.go b/errors_test.go
index 4bc347ca..00bb91ae 100644
--- a/errors_test.go
+++ b/errors_test.go
@@ -306,43 +306,6 @@ func TestErrAPISetValue(t *testing.T) {
 	testError(t, err, errAPI.Error(), columnCountErrMsg)
 }
 
-func TestErrProfiling(t *testing.T) {
-	t.Parallel()
-
-	t.Run(errInvalidCon.Error(), func(t *testing.T) {
-		var con driver.Conn
-		_, err := GetProfilingInfo(con)
-		testError(t, err, errInvalidCon.Error())
-	})
-
-	t.Run(errClosedCon.Error(), func(t *testing.T) {
-		c, err := NewConnector("", nil)
-		require.NoError(t, err)
-
-		con, err := c.Connect(context.Background())
-		require.NoError(t, err)
-		require.NoError(t, con.Close())
-
-		_, err = GetProfilingInfo(con)
-		testError(t, err, errClosedCon.Error())
-		require.NoError(t, c.Close())
-	})
-
-	t.Run(errProfilingInfoEmpty.Error(), func(t *testing.T) {
-		c, err := NewConnector("", nil)
-		require.NoError(t, err)
-
-		con, err := c.Connect(context.Background())
-		require.NoError(t, err)
-
-		_, err = GetProfilingInfo(con)
-		testError(t, err, errProfilingInfoEmpty.Error())
-
-		require.NoError(t, con.Close())
-		require.NoError(t, c.Close())
-	})
-}
-
 func TestDuckDBErrors(t *testing.T) {
 	db := openDB(t)
 	createTable(db, t, `CREATE TABLE duckdb_error_test(bar VARCHAR UNIQUE, baz INT32, u_1 UNION("string" VARCHAR))`)
diff --git a/profiling.go b/profiling.go
index cc4ec427..cd146a12 100644
--- a/profiling.go
+++ b/profiling.go
@@ -6,6 +6,7 @@ package duckdb
 import "C"
 
 import (
+	"database/sql"
 	"unsafe"
 )
 
@@ -22,30 +23,26 @@ type ProfilingInfo struct {
 }
 
 // GetProfilingInfo obtains all available metrics set by the current connection.
-func GetProfilingInfo(driverConn any) (ProfilingInfo, error) {
+func GetProfilingInfo(c *sql.Conn) (ProfilingInfo, error) {
 	info := ProfilingInfo{}
+	err := c.Raw(func(driverConn any) error {
+		con := driverConn.(*conn)
+		duckdbInfo := C.duckdb_get_profiling_info(con.duckdbCon)
+		if duckdbInfo == nil {
+			return getError(errProfilingInfoEmpty, nil)
+		}
 
-	con, ok := driverConn.(*conn)
-	if !ok {
-		return info, getError(errInvalidCon, nil)
-	}
-	if con.closed {
-		return info, getError(errClosedCon, nil)
-	}
-
-	duckdbInfo := C.duckdb_get_profiling_info(con.duckdbCon)
-	if duckdbInfo == nil {
-		return info, getError(errProfilingInfoEmpty, nil)
-	}
-
-	// Recursive tree traversal.
-	info.getMetrics(duckdbInfo)
-	return info, nil
+		// Recursive tree traversal.
+		info.getMetrics(duckdbInfo)
+		return nil
+	})
+	return info, err
 }
 
 func (info *ProfilingInfo) getMetrics(duckdbInfo C.duckdb_profiling_info) {
 	m := C.duckdb_profiling_info_get_metrics(duckdbInfo)
 	count := C.duckdb_get_map_size(m)
+	info.Metrics = make(map[string]string, count)
 
 	for i := C.idx_t(0); i < count; i++ {
 		key := C.duckdb_get_map_key(m, i)
diff --git a/profiling_test.go b/profiling_test.go
index 92ff840a..74f10411 100644
--- a/profiling_test.go
+++ b/profiling_test.go
@@ -3,7 +3,6 @@ package duckdb
 import (
 	"context"
 	"database/sql"
-	"fmt"
 	"testing"
 
 	"github.com/stretchr/testify/require"
@@ -14,37 +13,40 @@ func TestProfiling(t *testing.T) {
 
 	db, err := sql.Open("duckdb", "")
 	require.NoError(t, err)
-
 	con, err := db.Conn(context.Background())
 	require.NoError(t, err)
 
 	_, err = con.ExecContext(context.Background(), `PRAGMA enable_profiling = 'no_output'`)
 	require.NoError(t, err)
-
 	_, err = con.ExecContext(context.Background(), `PRAGMA profiling_mode = 'detailed'`)
 	require.NoError(t, err)
-
 	res, err := con.QueryContext(context.Background(), `SELECT range AS i FROM range(100) ORDER BY i`)
 	require.NoError(t, err)
 
-	var info ProfilingInfo
-	err = con.Raw(func(driverConn any) error {
-		info, err = GetProfilingInfo(driverConn)
-		return err
-	})
+	info, err := GetProfilingInfo(con)
 	require.NoError(t, err)
 
 	_, err = con.ExecContext(context.Background(), `PRAGMA disable_profiling`)
 	require.NoError(t, err)
-
 	require.NoError(t, res.Close())
 	require.NoError(t, con.Close())
 	require.NoError(t, db.Close())
 
 	// Verify the metrics.
-	// TODO: currently failing due to C API bug.
-	fmt.Println(info) // Dummy print to use variable.
-	// require.NotEmpty(t, info.Metrics, "metrics must not be empty")
-	// require.NotEmpty(t, info.Children, "children must not be empty")
-	// require.NotEmpty(t, info.Children[0].Metrics, "child metrics must not be empty")
+	require.NotEmpty(t, info.Metrics, "metrics must not be empty")
+	require.NotEmpty(t, info.Children, "children must not be empty")
+	require.NotEmpty(t, info.Children[0].Metrics, "child metrics must not be empty")
+}
+
+func TestErrProfiling(t *testing.T) {
+	t.Parallel()
+	db, err := sql.Open("duckdb", "")
+	require.NoError(t, err)
+	con, err := db.Conn(context.Background())
+	require.NoError(t, err)
+
+	_, err = GetProfilingInfo(con)
+	testError(t, err, errProfilingInfoEmpty.Error())
+	require.NoError(t, con.Close())
+	require.NoError(t, db.Close())
 }
diff --git a/scalar_udf_test.go b/scalar_udf_test.go
index feb939fb..0a59b306 100644
--- a/scalar_udf_test.go
+++ b/scalar_udf_test.go
@@ -368,7 +368,7 @@ func TestANYScalarUDF(t *testing.T) {
 	require.NoError(t, db.Close())
 }
 
-func TestScalarUDFErrors(t *testing.T) {
+func TestErrScalarUDF(t *testing.T) {
 	t.Parallel()
 
 	db, err := sql.Open("duckdb", "")

From ddeeff7503711cbb8b96d76c747045e2215fbd29 Mon Sep 17 00:00:00 2001
From: taniabogatsch <44262898+taniabogatsch@users.noreply.github.com>
Date: Tue, 24 Sep 2024 14:09:19 +0200
Subject: [PATCH 7/8] nit

---
 errors.go    | 16 +++++-----------
 profiling.go |  1 -
 2 files changed, 5 insertions(+), 12 deletions(-)

diff --git a/errors.go b/errors.go
index 3c84364c..054ce8ec 100644
--- a/errors.go
+++ b/errors.go
@@ -84,21 +84,17 @@ var (
 
 	errUnsupportedMapKeyType = errors.New("MAP key type not supported")
 
-	errAppenderCreation   = errors.New("could not create appender")
-	errAppenderInvalidCon = fmt.Errorf("%w: not a DuckDB driver connection", errAppenderCreation)
-	errAppenderClosedCon  = fmt.Errorf("%w: appender creation on a closed connection", errAppenderCreation)
-
-	errAppenderClose       = errors.New("could not close appender")
-	errAppenderDoubleClose = fmt.Errorf("%w: already closed", errAppenderClose)
-
+	errAppenderCreation         = errors.New("could not create appender")
+	errAppenderClose            = errors.New("could not close appender")
+	errAppenderDoubleClose      = fmt.Errorf("%w: already closed", errAppenderClose)
 	errAppenderAppendRow        = errors.New("could not append row")
 	errAppenderAppendAfterClose = fmt.Errorf("%w: appender already closed", errAppenderAppendRow)
-
-	errAppenderFlush = errors.New("could not flush appender")
+	errAppenderFlush            = errors.New("could not flush appender")
 
 	errEmptyName           = errors.New("empty name")
 	errInvalidDecimalWidth = fmt.Errorf("the DECIMAL with must be between 1 and %d", MAX_DECIMAL_WIDTH)
 	errInvalidDecimalScale = errors.New("the DECIMAL scale must be less than or equal to the width")
+	errSetSQLNULLValue     = errors.New("cannot write to a NULL column")
 
 	errScalarUDFCreate          = errors.New("could not create scalar UDF")
 	errScalarUDFNoName          = fmt.Errorf("%w: missing name", errScalarUDFCreate)
@@ -110,8 +106,6 @@ var (
 	errScalarUDFCreateSet       = fmt.Errorf("could not create scalar UDF set")
 	errScalarUDFAddToSet        = fmt.Errorf("%w: could not add the function to the set", errScalarUDFCreateSet)
 
-	errSetSQLNULLValue = errors.New("cannot write to a NULL column")
-
 	errProfilingInfoEmpty = errors.New("no profiling information available for this connection")
 
 	// Errors not covered in tests.
diff --git a/profiling.go b/profiling.go
index cd146a12..6fe8960a 100644
--- a/profiling.go
+++ b/profiling.go
@@ -50,7 +50,6 @@ func (info *ProfilingInfo) getMetrics(duckdbInfo C.duckdb_profiling_info) {
 
 		cKey := C.duckdb_get_varchar(key)
 		cValue := C.duckdb_get_varchar(value)
-
 		keyStr := C.GoString(cKey)
 		valueStr := C.GoString(cValue)
 

From 9c9511e1b19ea5249cbe8aec2af2e73617b98ba9 Mon Sep 17 00:00:00 2001
From: taniabogatsch <44262898+taniabogatsch@users.noreply.github.com>
Date: Tue, 24 Sep 2024 14:11:19 +0200
Subject: [PATCH 8/8] nit

---
 errors.go | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/errors.go b/errors.go
index 054ce8ec..9131d0ab 100644
--- a/errors.go
+++ b/errors.go
@@ -82,8 +82,6 @@ var (
 	errInvalidCon = errors.New("not a DuckDB driver connection")
 	errClosedCon  = errors.New("closed connection")
 
-	errUnsupportedMapKeyType = errors.New("MAP key type not supported")
-
 	errAppenderCreation         = errors.New("could not create appender")
 	errAppenderClose            = errors.New("could not close appender")
 	errAppenderDoubleClose      = fmt.Errorf("%w: already closed", errAppenderClose)
@@ -91,10 +89,11 @@ var (
 	errAppenderAppendAfterClose = fmt.Errorf("%w: appender already closed", errAppenderAppendRow)
 	errAppenderFlush            = errors.New("could not flush appender")
 
-	errEmptyName           = errors.New("empty name")
-	errInvalidDecimalWidth = fmt.Errorf("the DECIMAL with must be between 1 and %d", MAX_DECIMAL_WIDTH)
-	errInvalidDecimalScale = errors.New("the DECIMAL scale must be less than or equal to the width")
-	errSetSQLNULLValue     = errors.New("cannot write to a NULL column")
+	errUnsupportedMapKeyType = errors.New("MAP key type not supported")
+	errEmptyName             = errors.New("empty name")
+	errInvalidDecimalWidth   = fmt.Errorf("the DECIMAL with must be between 1 and %d", MAX_DECIMAL_WIDTH)
+	errInvalidDecimalScale   = errors.New("the DECIMAL scale must be less than or equal to the width")
+	errSetSQLNULLValue       = errors.New("cannot write to a NULL column")
 
 	errScalarUDFCreate          = errors.New("could not create scalar UDF")
 	errScalarUDFNoName          = fmt.Errorf("%w: missing name", errScalarUDFCreate)