Hi Sergei, Please find my input below.

diff --git a/sql/sql_select.cc b/sql/sql_select.cc index 0dfe95e81b0..fa07608177a 100644 --- a/sql/sql_select.cc +++ b/sql/sql_select.cc @@ -7910,28 +7910,27 @@ best_access_path(JOIN *join, can make an adjustment is a special case of the criteria used in ReuseRangeEstimateForRef-3. */ - if (table->opt_range_keys.is_set(key) && + auto use_range_estimates= table->opt_range_keys.is_set(key) && (const_part &

What is the reason for this change? Please restore the old code.

(((key_part_map)1 << table->opt_range[key].key_parts)-1)) == (((key_part_map)1 << table->opt_range[key].key_parts)-1) && table->opt_range[key].ranges == 1 && - records > (double) table->opt_range[key].rows) + records > (double) table->opt_range[key].rows; + if (use_range_estimates) { records= (double) table->opt_range[key].rows; trace_access_idx.add("used_range_estimates", "clipped down"); } else { + trace_access_idx.add("used_range_estimates",false); if (table->opt_range_keys.is_set(key)) { - trace_access_idx.add("used_range_estimates",false) - .add("cause", - "not better than ref estimates"); + cause= "not better than ref estimates";

As we have already discussed: Do not assign this to "cause". To avoid duplicate names, change the name above from "cause" to e.g. "reason".

} else { - trace_access_idx.add("used_range_estimates", false) - .add("cause", "not available"); + cause= "not available"; }

The same as above.

} } @@ -8217,9 +8215,10 @@ best_access_path(JOIN *join, best_uses_jbuf= TRUE; best_filter= 0; best_type= JT_HASH; + Json_writer_object trace_access_hash(thd); trace_access_hash.add("type", "hash"); trace_access_hash.add("index", "hj-key"); - trace_access_hash.add("cost", rnd_records); + trace_access_hash.add("est_records_cost", rnd_records);

Please use "rnd_records" instead of "est_records_cost".

trace_access_hash.add("cost", best); trace_access_hash.add("chosen", true); }

commit 0e8b82dbcbd8ae96e0758114c87e48061d603c5f Author: Sergei Krivonos <sergei.krivonos@mariadb.com> Date: Fri Nov 12 03:36:10 2021 +0200

MDEV-27036: add assert to detect duplicated JSON keys

diff --git a/sql/my_json_writer.cc b/sql/my_json_writer.cc index 9470ba57855..501f0b72318 100644 --- a/sql/my_json_writer.cc +++ b/sql/my_json_writer.cc @@ -39,6 +41,9 @@ inline void Json_writer::on_start_object() #if !defined(NDEBUG) || defined(JSON_WRITER_UNIT_TEST) if(!fmt_helper.is_making_writer_calls()) { + if(got_name != named_item_expected()){ + std::cout <<"got_name["<<got_name<<"] != named_item_expected["<<named_item_expected()<<']'<<std::endl; + }

First: as I've already mentioned, please don't write anything to to stderr or stdout directly. Use the sql_print_error() function. Second: the message is not informative. The above will print something like: got_name[1] != named_item_expected[0] which is not at all informative. What's "got_name[1]" ? Please change the printout to be something like: Json_writer: attempt to write invalid JSON. Last data in JSON: %s here %s should print last 256 chars in the JSON document.

VALIDITY_ASSERT(got_name == named_item_expected()); named_items_expectation.push_back(true); }

@@ -140,7 +150,19 @@ Json_writer& Json_writer::add_member(const char *name, size_t len) } #if !defined(NDEBUG) || defined(JSON_WRITER_UNIT_TEST) if (!fmt_helper.is_making_writer_calls()) + { + VALIDITY_ASSERT(!got_name); got_name= true; + VALIDITY_ASSERT(named_items.size()); + auto& named_items_keys= named_items.top(); + auto emplaced= named_items_keys.emplace(name, len); + auto is_uniq_key= emplaced.second; + if(!is_uniq_key) + { + std::cerr << "Duplicated key: " << *emplaced.first << std::endl; + VALIDITY_ASSERT(is_uniq_key);

Same input as above: use sql_print_error and make the error message helpful.

+ } + } #endif return *this; }

commit 57e8f68955954ff96104c8356733bfa73feae849 (HEAD -> bb-10.8-MDEV-27036, origin/bb-10.8-MDEV-27036) Author: Sergei Krivonos <sergei.krivonos@mariadb.com> Date: Mon Nov 15 05:57:25 2021 +0200

MDEV-27036: unittest JSON object member name collision

diff --git a/unittest/sql/my_json_writer-t.cc b/unittest/sql/my_json_writer-t.cc index 6398a589c33..7d20802527d 100644 --- a/unittest/sql/my_json_writer-t.cc +++ b/unittest/sql/my_json_writer-t.cc @@ -119,7 +119,14 @@ int main(int args, char **argv) ok(w.invalid_json, "JSON array end of object"); }

- + { + Json_writer w; + w.start_object(); + w.add_member("name").add_ll(1); + w.add_member("name").add_ll(2); + w.end_object(); + ok(w.invalid_json, "JSON object member name collision"); + }

Please add more unit test coverage. Check that this is accepted: { "foo": { "foo": {} } } Check that this is not accepted: { "foo": { "bar": {} }, "foo": "something else" } BR Sergei -- Sergei Petrunia, Software Developer MariaDB Corporation | Skype: sergefp | Blog: http://petrunia.net