Here's the diff I'm using: ```diff diff --git a/datasette/views/table.py b/datasette/views/table.py index d66adb8..f15ef1e 100644 --- a/datasette/views/table.py +++ b/datasette/views/table.py @@ -1,3 +1,4 @@ +import asyncio import itertools import json

@@ -5,6 +6,7 @@ import markupsafe

from datasette.plugins import pm from datasette.database import QueryInterrupted +from datasette import tracer from datasette.utils import ( await_me_maybe, CustomRow, @@ -150,6 +152,16 @@ class TableView(DataView): default_labels=False, _next=None, _size=None, + ): + with tracer.trace_child_tasks(): + return await self._data_traced(request, default_labels, _next, _size) + + async def _data_traced( + self, + request, + default_labels=False, + _next=None, + _size=None, ): database_route = tilde_decode(request.url_vars["database"]) table_name = tilde_decode(request.url_vars["table"]) @@ -159,6 +171,20 @@ class TableView(DataView): raise NotFound("Database not found: {}".format(database_route)) database_name = db.name

• For performance profiling purposes, ?_parallel=1 turns on asyncio.gather

• async def _gather_parallel(*args):
• return await asyncio.gather(*args) +
• async def _gather_sequential(*args):
• results = []
• for fn in args:
• results.append(await fn)
• return results +
• gather = (
• _gather_parallel if request.args.get("_parallel") else _gather_sequential

• ) + # If this is a canned query, not a table, then dispatch to QueryView instead canned_query = await self.ds.get_canned_query( database_name, table_name, request.actor @@ -174,8 +200,12 @@ class TableView(DataView): write=bool(canned_query.get("write")), )

• is_view = bool(await db.get_view_definition(table_name))

• table_exists = bool(await db.table_exists(table_name))
• is_view, table_exists = map(
• bool,
• await gather(
• db.get_view_definition(table_name), db.table_exists(table_name)
• ),

• )

   # If table or view not found, return 404
   if not is_view and not table_exists:
  

  @@ -497,33 +527,44 @@ class TableView(DataView): ) )

• if not nofacet:

• for facet in facet_instances:
• (
• async def execute_facets():
• if not nofacet:

• Run them in parallel

• facet_awaitables = [facet.facet_results() for facet in facet_instances]
• facet_awaitable_results = await gather(*facet_awaitables)
• for ( instance_facet_results, instance_facets_timed_out,
• ) = await facet.facet_results()
• for facet_info in instance_facet_results:
• base_key = facet_info["name"]
• key = base_key
• i = 1
• while key in facet_results:
• i += 1
• key = f"{base_key}_{i}"
• facet_results[key] = facet_info

• facets_timed_out.extend(instance_facets_timed_out)

• Calculate suggested facets

• ) in facet_awaitable_results:
• for facet_info in instance_facet_results:
• base_key = facet_info["name"]
• key = base_key
• i = 1
• while key in facet_results:
• i += 1
• key = f"{base_key}_{i}"
• facet_results[key] = facet_info
• facets_timed_out.extend(instance_facets_timed_out) + suggested_facets = []
• if (
• self.ds.setting("suggest_facets")
• and self.ds.setting("allow_facet")
• and not _next
• and not nofacet
• and not nosuggest
• ):
• for facet in facet_instances:
• suggested_facets.extend(await facet.suggest()) +
• async def execute_suggested_facets():

• Calculate suggested facets

• if (
• self.ds.setting("suggest_facets")
• and self.ds.setting("allow_facet")
• and not _next
• and not nofacet
• and not nosuggest
• ):

• Run them in parallel

• facet_suggest_awaitables = [
• facet.suggest() for facet in facet_instances
• ]
• for suggest_result in await gather(*facet_suggest_awaitables):
• suggested_facets.extend(suggest_result) +
• await gather(execute_facets(), execute_suggested_facets())

   # Figure out columns and rows for the query
   columns = [r[0] for r in results.description]
  

  ```