issue_comments: 1111602802

Tried this but I'm getting back an empty JSON array of traces at the bottom of the page most of the time (intermittently it works correctly):

```diff diff --git a/datasette/database.py b/datasette/database.py index ba594a8..d7f9172 100644 --- a/datasette/database.py +++ b/datasette/database.py @@ -7,7 +7,7 @@ import sys import threading import uuid

-from .tracer import trace +from .tracer import trace, trace_child_tasks from .utils import ( detect_fts, detect_primary_keys, @@ -207,30 +207,31 @@ class Database: time_limit_ms = custom_time_limit

         with sqlite_timelimit(conn, time_limit_ms):

• try:
• cursor = conn.cursor()
• cursor.execute(sql, params if params is not None else {})
• max_returned_rows = self.ds.max_returned_rows
• if max_returned_rows == page_size:
• max_returned_rows += 1
• if max_returned_rows and truncate:
• rows = cursor.fetchmany(max_returned_rows + 1)
• truncated = len(rows) > max_returned_rows
• rows = rows[:max_returned_rows]
• else:
• rows = cursor.fetchall()
• truncated = False
• except (sqlite3.OperationalError, sqlite3.DatabaseError) as e:
• if e.args == ("interrupted",):
• raise QueryInterrupted(e, sql, params)
• if log_sql_errors:
• sys.stderr.write(
• "ERROR: conn={}, sql = {}, params = {}: {}\n".format(
• conn, repr(sql), params, e
• with trace("sql", database=self.name, sql=sql.strip(), params=params):
• try:
• cursor = conn.cursor()
• cursor.execute(sql, params if params is not None else {})
• max_returned_rows = self.ds.max_returned_rows
• if max_returned_rows == page_size:
• max_returned_rows += 1
• if max_returned_rows and truncate:
• rows = cursor.fetchmany(max_returned_rows + 1)
• truncated = len(rows) > max_returned_rows
• rows = rows[:max_returned_rows]
• else:
• rows = cursor.fetchall()
• truncated = False
• except (sqlite3.OperationalError, sqlite3.DatabaseError) as e:
• if e.args == ("interrupted",):
• raise QueryInterrupted(e, sql, params)
• if log_sql_errors:
• sys.stderr.write(
• "ERROR: conn={}, sql = {}, params = {}: {}\n".format(
• conn, repr(sql), params, e
• ) )
• )
• sys.stderr.flush()
• raise
• sys.stderr.flush()

• raise

       if truncate:
           return Results(rows, truncated, cursor.description)
  

  @@ -238,9 +239,8 @@ class Database: else: return Results(rows, False, cursor.description)

• with trace("sql", database=self.name, sql=sql.strip(), params=params):

• results = await self.execute_fn(sql_operation_in_thread)
• return results
• with trace_child_tasks():

• return await self.execute_fn(sql_operation_in_thread)

  @property def size(self): ```